A Minimum Assumption Tornado-Hazard Probability Model.

NASA Astrophysics Data System (ADS)

Schaefer, Joseph T.; Kelly, Donald L.; Abbey, Robert F.

1986-12-01

One of the principle applications of climatological tornado data is in tornado-hazard assessment. To perform such a hazard-potential determination, historical tornado characteristics in either a regional or tom area are complied. A model is then used to determine a site-specific point probability of a tornado greater than a specified intensity occurring. Various models require different climatological input. However, a knowledge of the mean values of tornado track width, tornado track width, tornado affected area and tornado occurrence rate as both a function of tornado intensity and geographic area, along with a violence frequency distribution, enable Mod of the models to be applied.The NSSFC-NRC tornado data base is used to supply input for the determination of these parameters over the United States. This climatic data base has undergone extensive updating and quality control since it was last reported. For track parameters, internally redundant data were used to cheek consistency. Further, reports which derivated significantly from the mean wore individually checked. Intensity data have been compared with the University of Chicago DAPPLE tornado base. All tornadoes whose recorded intensifies differed by more than one category were reclassified by an independent scientist so that the two data sets are consistent.

Superoutbreak tornadoes of April 3, 1974 as seen in ATS pictures

NASA Technical Reports Server (NTRS)

Fujita, T. T.; Forbes, G. S.

1974-01-01

A total of 122 confirmed tornadoes during the April 3-4 superoutbreak is studied by conducting an extensive aerial survey for mapping the precise paths and characteristics of individual tornadoes. Major conclusions are that the life of a tornado varies between 1 and 125 min, that 74% of the tornadoes can be grouped together into 30 tornado families with the mean family life about 5 times the mean individual life, that the identification of family-producing thunderstorms appears to be extremely useful in issuing a tornado alert, and that a tornado-producing thunderstorm within a 50-mile radar range often shows a hook echo on PPI scope as a probable tornado indicator.

Tame a Tornado

ERIC Educational Resources Information Center

Cronin, Jim

2003-01-01

The author was looking for a demonstration that actually used wind shear forces to set up the tornado effect when he saw a video produced by The Tornado Project called "Secrets of the Tornado". This video not only shows dozens of actual tornadoes, but also gives construction techniques for several different styles of tornado boxes that are…

Predictors of compliance with tornado warnings issued in Joplin, Missouri, in 2011.

PubMed

Paul, Bimal Kanti; Stimers, Mitchel; Caldas, Marcellus

2015-01-01

Joplin, a city in the southwest corner of Missouri, United States, suffered an EF-5 tornado in the late afternoon of 22 May 2011. This event, which claimed the lives of 162 people, represents the deadliest single tornado to strike the US since modern record-keeping began in 1950. This study examines the factors associated with responses to tornado warnings. Based on a post-tornado survey of survivors in Joplin, it reveals that tornado warnings were adequate and timely. Multivariate logistic regression identified four statistically significant determinants of compliance with tornado warnings: number of warning sources, whether respondents were at home when the tornado struck, past tornado experience, and gender. The findings suggest several recommendations, the implementation of which will further improve responses to tornado warnings. © 2014 The Author(s). Disasters © Overseas Development Institute, 2014.

On the temporal and spatial characteristics of tornado days in the United States

NASA Astrophysics Data System (ADS)

Moore, Todd W.

2017-02-01

More tornadoes are produced per year in the United States than in any other country, and these tornadoes have produced tremendous losses of life and property. Understanding how tornado activity will respond to climate change is important if we wish to prepare for future changes. Trends in various tornado and tornado day characteristics, including their annual frequencies, their temporal variability, and their spatial distributions, have been reported in the past few years. This study contributes to this body of literature by further analyzing the temporal and spatial characteristics of tornado days in the United States. The analyses performed in this study support previously reported findings in addition to providing new perspectives, including that the temporal trends are observed only in low-frequency and high-frequency tornado days and that the eastward shift in tornado activity is produced, in part, by the increasing number of high-frequency tornado days, which tend to occur to the east of the traditionally depicted tornado alley in the Great Plains.

Tornadoes: Nature's Most Violent Storms. A Preparedness Guide Including Safety Information for Schools.

ERIC Educational Resources Information Center

American National Red Cross, Washington, DC.

This preparedness guide explains and describes tornadoes, and includes safety information for schools. A tornado is defined as a violently rotating column of air extending from a thunderstorm to the ground. The guide explains the cause of tornadoes, provides diagrams of how they form, describes variations of tornadoes, and classifies tornadoes by…

Climate analysis of tornadoes in China

NASA Astrophysics Data System (ADS)

Yao, Yeqing; Yu, Xiaoding; Zhang, Yijun; Zhou, Zijiang; Xie, Wusan; Lu, Yanyu; Yu, Jinlong; Wei, Lingxiang

2015-06-01

Based on analysis of historical tornado observation data provided by the primary network of national weather stations in China for the period from 1960 to 2009, it is found that most tornadoes in China (85%) occurred over plains. Specifically, large numbers of tornado occurrences are found in the Northeast Plain, the North China Plain, the middle-lower Yangtze Plain, and the Pearl River Delta Plain. A flat underlying surface is conducive to tornado occurrence, while the latitudal variation of tornado occurrence in China is not so obvious. Tornadoes mainly occur in summer, and the highest frequency is in July. Note that the beginning and the time span of tornado outbreaks are different in North and South China. Tornadoes occur during May-September in South China (south of 25°N), June-September in Northeast China (north of 40°N), July-September in the middle-lower Yangtze Plain, and July-August in North China (between 25° and 40°N). More than 80% of total tornadoes occurred during the above periods for the specific regions. The 1960s and 1970s have seen about twice the average number of tornadoes (7.5 times per year) compared to the mean for 1960-2009. The most frequent occurrence of tornado was in the early and mid 1960s; there were large fluctuations in the 1970s; and the number of tornadoes in the 1980s approached the 50-yr average. Tornado occurrences gradually decreased in the late 1980s, and an abrupt change with dramatic decrease occurred in 1994. The decrease in the tornado occurrence frequency is consistent with the simultaneous climatic change in the meteorological elements that are favorable for tornado formation. Tornado formation requires large vertical wind shear and sufficient atmospheric moisture content near the ground. Changes in the vertical wind shear at both 0-1 and 0-6 km appear to be one important factor that results in the decrease in tornado formation. The changing tendency of relative humidity also has contributed to the decrease in tornado formation in China.

what is a tornado?

Science.gov Websites

all the same. It appears that tornadoes arise in many different ways, and perhaps different process can be associated with the tornado at different times in its life cycle. Moreover, not all tornadoes , mesocyclone) be? Where do you propose to put the dividing lines between tornado-tornado cyclone-mesocyclone? c

Relationship between tornadoes and hook echoes on April 3, 1974

NASA Technical Reports Server (NTRS)

Forbes, G. S.

1975-01-01

Radar observations of tornado families occurring on April 3, 1974 are discussed. Of the 93 tornadoes included in the sample, 81% were associated with hook-like echoes with appendages at least 40 deg to the south of the echo movement. At least one tornado was associated with 62% of the hook-like echoes observed. All of the tornadoes with intensities of F 4 and F 5 were produced by hook-like echoes; the mean intensity of all tornadoes associated with this type of echo was F 3, while the mean intensity of the remaining tornadoes was F1. The tornadic hook-like echoes moved to the right of the non-tornadic echoes forming a tornado line in advance of the squall line. Some tornadoes were associated with 'spiral' echoes.

Economics and societal impacts of tornadoes

NASA Astrophysics Data System (ADS)

Bluestein, Howard B.

2011-08-01

During the spring of 2011, there were a record number of unusually strong and devastating tornadoes in the United States, which killed more than 500 people, the most in the country since 1953. Tornadoes are responsible for more than $1 billion annually (adjusted to 2007 U.S. dollars) in property damage and for disrupting thousands of lives and businesses. The most notable tornado this past spring devastated Joplin, Mo.; tornadoes also struck such diverse locations as Springfield, Mass.; Tuscaloosa, Ala.; Raleigh, N. C.; communities near Oklahoma City, Okla.; Minneapolis, Minn.; central and east Texas; Philadelphia, Pa.; and St. Louis, Mo. It is therefore timely to assess the economic and societal impacts of tornadoes. In this book the authors use various statistical techniques to evaluate the cost of tornadoes to society. They begin by reviewing the methodologies of formulating a tornado climatology across diverse regions according to tornado intensity, deaths, injuries, and property damage, and they then provide a history of the U.S. National Weather Service's (NWS) public warning efforts, describe tornado shelters and how the public responds to warnings, and suggest ways to reduce tornado risk.

Survey of a violent tornado in far southwestern Texas: The Bakersfield Valley storm of June 1, 1990

NASA Astrophysics Data System (ADS)

Woodall, Gary R.; Mathews, George N.

During the late afternoon of June 1, 1990, a violent tornado struck northern and eastern Pecos County, Texas. This tornado killed two people, injured 21, and caused over $5 million in damage. The tornado passed over the unincorporated ranching community of Bakersfield Valley, so the tornado will be referred to as the Bakersfield Valley (BV) tornado.

Pneumonia cases following an EF-5 tornado.

PubMed

Forshee-Hakala, Beth A

2015-07-01

Infections following a natural disaster such as an EF-5 tornado can be atypical and difficult to treat. Studies have looked at illness following several natural disasters, but few have studied respiratory illness following a tornado. A review of patients with pneumonia admitted during the period from May 22, 2009, through May 21, 2012, was completed. The Tornado Zone Group included adult patients who lived or worked in the tornado zone during the year following the tornado. Data were isolated by number of pneumonia cases within and outside the tornado zone per month per year. An analysis of variance comparing the number of pneumonia cases from the tornado zone per month per year was significant at F2,38 = 12.93 and P < .001, with increased cases in the Tornado Zone Group (P < .05). A t test comparing age of pneumonia patients found Tornado Zone patients to be younger than controls (t390 = 5.14; P < .01). Microbes isolated from the Tornado Zone Group included uncommon pathogens not isolated during the 2 years prior. The number of pneumonia cases may increase following tornadoes. Although current guidelines recommend narrow-spectrum antibiotics for community-acquired pneumonia, results of this study suggest the possible need for broader antimicrobial coverage after tornadoes. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.

Dynamics of a Solar Prominence Tornado Observed by SDO/AIA on 2012 November 7-8

NASA Astrophysics Data System (ADS)

Mghebrishvili, Irakli; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil; Ramishvili, Giorgi; Shergelashvili, Bidzina; Veronig, Astrid; Poedts, Stefaan

2015-09-01

We study the detailed dynamics of a solar prominence tornado using time series of 171, 304, 193, and 211 Å spectral lines obtained by the Solar Dynamics Observatory/Atmospheric Imaging Assembly during 2012 November 7-8. The tornado first appeared at 08:00 UT, November 07, near the surface, gradually rose upwards with the mean speed of ˜1.5 km s-1 and persisted over 30 hr. Time-distance plots show two patterns of quasi-periodic transverse displacements of the tornado axis with periods of 40 and 50 minutes at different phases of the tornado evolution. The first pattern occurred during the rising phase and can be explained by the upward motion of the twisted tornado. The second pattern occurred during the later stage of evolution when the tornado already stopped rising and could be caused either by MHD kink waves in the tornado or by the rotation of two tornado threads around a common axis. The later hypothesis is supported by the fact that the tornado sometimes showed a double structure during the quasi-periodic phase. 211 and 193 Å spectral lines show a coronal cavity above the prominence/tornado, which started expansion at ˜13:00 UT and continuously rose above the solar limb. The tornado finally became unstable and erupted together with the corresponding prominence as coronal mass ejection (CME) at 15:00 UT, November 08. The final stage of the evolution of the cavity and the tornado-related prominence resembles the magnetic breakout model. On the other hand, the kink instability may destabilize the twisted tornado, and consequently prominence tornadoes can be used as precursors for CMEs.

DYNAMICS OF A SOLAR PROMINENCE TORNADO OBSERVED BY SDO/AIA ON 2012 NOVEMBER 7–8

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mghebrishvili, Irakli; Zaqarashvili, Teimuraz V.; Kukhianidze, Vasil

We study the detailed dynamics of a solar prominence tornado using time series of 171, 304, 193, and 211 Å spectral lines obtained by the Solar Dynamics Observatory/Atmospheric Imaging Assembly during 2012 November 7–8. The tornado first appeared at 08:00 UT, November 07, near the surface, gradually rose upwards with the mean speed of ∼1.5 km s{sup −1} and persisted over 30 hr. Time–distance plots show two patterns of quasi-periodic transverse displacements of the tornado axis with periods of 40 and 50 minutes at different phases of the tornado evolution. The first pattern occurred during the rising phase and canmore » be explained by the upward motion of the twisted tornado. The second pattern occurred during the later stage of evolution when the tornado already stopped rising and could be caused either by MHD kink waves in the tornado or by the rotation of two tornado threads around a common axis. The later hypothesis is supported by the fact that the tornado sometimes showed a double structure during the quasi-periodic phase. 211 and 193 Å spectral lines show a coronal cavity above the prominence/tornado, which started expansion at ∼13:00 UT and continuously rose above the solar limb. The tornado finally became unstable and erupted together with the corresponding prominence as coronal mass ejection (CME) at 15:00 UT, November 08. The final stage of the evolution of the cavity and the tornado-related prominence resembles the magnetic breakout model. On the other hand, the kink instability may destabilize the twisted tornado, and consequently prominence tornadoes can be used as precursors for CMEs.« less

Modeling the Excitation of Seismic Waves by the Joplin Tornado

NASA Astrophysics Data System (ADS)

Valovcin, Anne; Tanimoto, Toshiro

2017-10-01

Tornadoes generate seismic signals when they contact the ground. Here we examine the signals excited by the Joplin tornado, which passed within 2 km of a station in the Earthscope Transportable Array. We model the tornado-generated vertical seismic signal at low frequencies (0.01-0.03 Hz) and solve for the strength of the seismic source. The resulting source amplitude is largest when the tornado was reported to be strongest (EF 4-5), and the amplitude is smallest when the tornado was weak (EF 0-2). A further understanding of the relationship between source amplitude and tornado intensity could open up new ways to study tornadoes from the ground.

Kinetic Energy of Tornadoes in the United States

PubMed Central

Fricker, Tyler; Elsner, James B.

2015-01-01

Tornadoes can cause catastrophic destruction. Here total kinetic energy (TKE) as a metric of destruction is computed from the fraction of the tornado path experiencing various damage levels and a characteristic wind speed for each level. The fraction of the path is obtained from a model developed for the Nuclear Regulatory Commission that combines theory with empirical data. TKE is validated as a useful metric by comparing it to other indexes and loss indicators. Half of all tornadoes have TKE exceeding 62.1 GJ and a quarter have TKE exceeding 383.2 GJ. One percent of the tornadoes have TKE exceeding 31.9 TJ. April has more energy than May with fewer tornadoes; March has more energy than June with half as many tornadoes. September has the least energy but November and December have the fewest tornadoes. Alabama ranks number one in terms of tornado energy with 2.48 PJ over the period 2007–2013. TKE can be used to help better understand the changing nature of tornado activity. PMID:26132830

Buoyancy and shear characteristics of hurricane-tornado environments

NASA Technical Reports Server (NTRS)

Mccaul, Eugene W., Jr.

1991-01-01

This study presents detailed composite profiles of temperature, moisture, and wind constructed for tornado environments in tropical cyclones that affected the U.S. between 1948 and 1986. Winds are composited in components radial and tangential to the tropical cyclone center at observation time. Guided by observed patterns of tornado occurrence, composites are constructed for a variety of different stratifications of the data, including proximity to tornadoes, position relative to the cyclone center, time of day, time after cyclone landfall, cyclone translation speed, and landfall location. The composites are also compared to composite soundings from Great Plains tornado environments. A variety of sounding parameters are examined to see which are most closely related to the tornado distribution patterns. Lower-tropospheric vertical shears are found to be stronger in the tropical cyclone tornado environments than on the Great Plains. Buoyancy for the tropical cyclone tornado cases is much smaller than that seen with Great Plains tornado events and exhibits a weak negative correlation with tornado outbreak severity.

Kinetic Energy of Tornadoes in the United States.

PubMed

Fricker, Tyler; Elsner, James B

2015-01-01

Tornadoes can cause catastrophic destruction. Here total kinetic energy (TKE) as a metric of destruction is computed from the fraction of the tornado path experiencing various damage levels and a characteristic wind speed for each level. The fraction of the path is obtained from a model developed for the Nuclear Regulatory Commission that combines theory with empirical data. TKE is validated as a useful metric by comparing it to other indexes and loss indicators. Half of all tornadoes have TKE exceeding 62.1 GJ and a quarter have TKE exceeding 383.2 GJ. One percent of the tornadoes have TKE exceeding 31.9 TJ. April has more energy than May with fewer tornadoes; March has more energy than June with half as many tornadoes. September has the least energy but November and December have the fewest tornadoes. Alabama ranks number one in terms of tornado energy with 2.48 PJ over the period 2007-2013. TKE can be used to help better understand the changing nature of tornado activity.

Observations and laboratory simulations of tornadoes in complex topographical regions

NASA Astrophysics Data System (ADS)

Karstens, Christopher Daniel

Aerial photos taken along the damage paths of the Joplin, MO, and Tuscaloosa-Birmingham, AL, tornadoes of 2011 captured and preserved several unique patterns of damage. In particular, a few distinct tree-fall patterns were noted along the Tuscaloosa-Birmingham tornado track that appeared highly influenced by the underlying topography. One such region was the focus of a damage survey and motivated laboratory vortex simulations with a 3-D foam representation of the underlying topography, in addition to simulations performed with idealized 2D topographic features, using Iowa State University's tornado simulator. The purpose of this dissertation is to explore various aspects related to the interaction of a tornado or a tornado-like vortex with its underlying topography. Three topics are examined: 1) Analysis of tornado-induced tree-fall using aerial photography from the Joplin, MO, and Tuscaloosa-Birmingham, AL, tornadoes of 2011, 2) Laboratory investigation of topographical influences on a simulated tornado-like vortex, and 3) On the use of non-standard EF-scale damage indicators to categorize tornadoes.

Can We Eliminate the Major Tornado Threats in Tornado Alley?

NASA Astrophysics Data System (ADS)

Tao, R.

2014-03-01

The recent devastating tornado attacks in Oklahoma, Iowa, Nebraska, and South Dakota raise an important question: can we do something to eliminate the major tornado threats in Tornado Alley? Violent tornado attacks in Tornado Alley are starting from intensive encounters between the northbound warm air flow and southbound cold air flow. As there is no mountain in Tornado Alley ranging from west to east to weaken or block such air flows, some encounters are violent, creating instability: The strong wind changes direction and increases in speed and height. As a result, it creates a supercell, violent vortex, an invisible horizontal spinning motion in the lower atmosphere. When the rising air tilts the spinning air from horizontal to vertical, tornadoes with radii of miles are formed and cause tremendous damage. Here we show that if we build three east-west great walls in the American Midwest, 300m high and 50m wide, one in North Dakota, one along the border between Kansas and Oklahoma to east, and the third one in the south Texas and Louisiana, we will diminish the tornado threats in the Tornado Alley forever. We may also build such great walls at some area with frequent devastating tornado attacks first, then gradually extend it. This research is supported in part by a grant from US Naval Research Lab.

77 FR 41475 - El Expreso Group, LLC-Asset Acquisition-CUSA EE, LLC D/B/A El Expreso

Federal Register 2010, 2011, 2012, 2013, 2014

2012-07-13

... carrier operating authority (MC-276747), Tornado also holds intrastate authority in Texas. Tornado's... Expreso Group's application identified Tornado Bus Company, Inc. (Tornado), an affiliate, as a second... and assignment of certain executory contracts and unexpired leases. Applicant and Tornado, a motor...

Disaster Preparation and Recovery - Multiple Languages

MedlinePlus

... Telephone Alerts - العربية (Arabic) PDF Healthy Roads Media Tornadoes - English PDF Tornadoes - العربية (Arabic) PDF Healthy Roads Media Volunteers Needed - ... Telephone Alerts - bosanski (Bosnian) MP4 Healthy Roads Media Tornadoes - English PDF Tornadoes - bosanski (Bosnian) PDF Tornadoes - English ...

Impact of tornadoes on hospital admissions for acute cardiovascular events.

PubMed

Silva-Palacios, Federico; Casanegra, Ana Isabel; Shapiro, Alan; Phan, Minh; Hawkins, Beau; Li, Ji; Stoner, Julie; Tafur, Alfonso

2015-11-01

There is a paucity of data describing cardiovascular events after tornado outbreaks. We proposed to study the effects of tornadoes on the incidence of cardiovascular events at a tertiary care institution. Hospital admission records from a single center situated in a tornado-prone area three months before and after a 2013 tornado outbreak were abstracted. To control for seasonal variation, we also abstracted data from the same period of the prior year (control). Hospital admissions for cardiovascular events (CVEs) including acute myocardial infarction, stroke and venous thromboembolism (VTE) were summated by zip codes, and compared by time period. There were 22,607 admissions analyzed, of which 6,705 (30%), 7,980 (35%), and 7,922 (35%) were during the pre-tornado, post-tornado, and control time frames, respectively. There were 344 CVE in the controls, 317 CVE in pre-tornado and 364 CVEs in post tornado periods. There was no difference in the prevalence of CVE during the post-tornado season compared with the control (PPR=1.05 95% CI: 0.91 to 1.21, p=0.50) or the pre-tornado season (PPR=0.96, 95% CI: 0.83 to 1.21, p=0.63). In conclusion, tornado outbreaks did not increase the prevalence of cardiovascular events. In contrast to the effect of hurricanes, implementation of a healthcare policy change directed toward the early treatment and prevention of cardiovascular events after tornadoes does not seem warranted. Copyright © 2015 Elsevier Ltd. All rights reserved.

Impact of tornadoes on hospital admissions for acute cardiovascular events

PubMed Central

Silva-Palacios, Federico; Casanegra, Ana Isabel; Shapiro, Alan; Phan, Minh; Hawkins, Beau; Li, Ji; Stoner, Julie; Tafur, Alfonso

2016-01-01

Background There is a paucity of data describing cardiovascular events after tornado outbreaks. We proposed to study the effects of tornadoes on the incidence of cardiovascular events at a tertiary care institution. Population and methods Hospital admission records from a single center situated in a tornado-prone area three months before and after a 2013 tornado outbreak were abstracted. To control for seasonal variation, we also abstracted data from the same period of the prior year (control). Hospital admissions for cardiovascular events (CVEs) including acute myocardial infarction, stroke and venous thromboembolism (VTE) were summated by zip codes, and compared by time period. Results There were 22,607 admissions analyzed, of which 6,705 (30%), 7,980 (35%), and 7,922 (35%) were during the pre-tornado, post-tornado, and control time frames, respectively. There were 344 CVE in the controls, 317 CVE in pre-tornado and 364 CVEs in post tornado periods. There was no difference in the prevalence of CVE during the post-tornado season compared with the control (PPR = 1.05 95% CI: 0.91 to 1.21, p = 0.50) or the pre-tornado season (PPR= 0.96, 95% CI: 0.83 to 1.21, p = 0.63). Conclusion In conclusion, tornado outbreaks did not increase the prevalence of cardiovascular events. In contrast to the effect of hurricanes, implementation of a healthcare policy change directed toward the early treatment and prevention of cardiovascular events after tornadoes does not seem warranted. PMID:26388119

Tornado damage risk assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reinhold, T.A.; Ellingwood, B.

1982-09-01

Several proposed models were evaluated for predicting tornado wind speed probabilities at nuclear plant sites as part of a program to develop statistical data on tornadoes needed for probability-based load combination analysis. A unified model was developed which synthesized the desired aspects of tornado occurrence and damage potential. The sensitivity of wind speed probability estimates to various tornado modeling assumptions are examined, and the probability distributions of tornado wind speed that are needed for load combination studies are presented.

Three scales of motions associated with tornadoes. [Cyclones, tornadoes, and suction vortexs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forbes, G.S.

1978-03-01

This dissertation explores three scales of motion commonly associated with tornadoes, and the interaction of these scales: the tornado cyclone, the tornado, and the suction vortex. The goal of the research is to specify in detail the character and interaction of these scales of motion to explain tornadic phenomena.

Close-up view of 20 March 1976 tornadoes - Sinking cloud tops to suction vortices

NASA Technical Reports Server (NTRS)

Fujita, T. T.; Forbes, G. S.; Umenhofer, T. A.

1976-01-01

The article describes an airborne mission using a Learjet to secure direct data on a family of tornadoes spawned by a rotating thunderstorm in the Missouri-Illinois-Indiana area in March 1976 following an unusually warm February. Weakening of the tornado following increased cloud-scale vertical motion, predicted by a model constructed by Fujita (1972), was confirmed. The aircraft inspected overshooting cloud tops, examined subsidence (holes and depressions) in anvil tops it overflew, and surveyed footprints left by the tornadoes and tornado-blown litter on the ground traversed by the disturbances. Subsidence of cloud tops in advance of violent tornadoes below was confirmed. Isolated and multiple suction vortices left their characteristic ground marks; three scales of motion: tornado cyclone, tornado, and suction vortex, are evidenced by the ground truth.

Increased variability of tornado occurrence in the United States.

PubMed

Brooks, Harold E; Carbin, Gregory W; Marsh, Patrick T

2014-10-17

Whether or not climate change has had an impact on the occurrence of tornadoes in the United States has become a question of high public and scientific interest, but changes in how tornadoes are reported have made it difficult to answer it convincingly. We show that, excluding the weakest tornadoes, the mean annual number of tornadoes has remained relatively constant, but their variability of occurrence has increased since the 1970s. This is due to a decrease in the number of days per year with tornadoes combined with an increase in days with many tornadoes, leading to greater variability on annual and monthly time scales and changes in the timing of the start of the tornado season. Copyright © 2014, American Association for the Advancement of Science.

A Tornado on the Sun

NASA Astrophysics Data System (ADS)

Kohler, Susanna

2015-10-01

On 7 November, 2012 at 08:00 UT, an enormous tornado of plasma rose from the surface of the Sun. It twisted around and around, climbing over the span of 10 hours to a height of 50 megameters roughly four times the diameter of the Earth! Eventually, this monster tornado became unstable and erupted violently as a coronal mass ejection (CME).Now, a team of researchers has analyzed this event in an effort to better understand the evolution of giant solar tornadoes like this one.Oscillating AxisIn this study, led by Irakli Mghebrishvili and Teimuraz Zaqarashvili of Ilia State University (Georgia), images taken by the Solar Dynamics Observatorys Atmospheric Imaging Assembly were used to track the tornados motion as it grew, along with a prominence, on the solar surface.The team found that as the tornado evolved, there were several intervals during which it moved back and forth quasi-periodically. The authors think these oscillations were due to one of two effects when the tornado was at a steady height: either twisted threads of the tornado were rotating around each other, or a magnetic effect known as kink waves caused the tornado to sway back and forth.Determining which effect was at work is an important subject of future research, because the structure and magnetic configuration of the tornado has implications for the next stage of this tornados evolution: eruption.Eruption from InstabilitySDO/AIA 3-channel composite image of the tornado an hour before it erupted in a CME. A coronal cavity has opened above the tornado; the top of the cavity is indicated by an arrow. [NASA/SDO/AIA; Mghebrishvili et al. 2015]Thirty hours after its formation, the tornado (and the solar prominence associated with it) erupted as a CME, releasing enormous amounts of energy. In the images from shortly before that moment, the authors observed a cavity open in the solar corona above the tornado. This cavity gradually expanded and rose above the solar limb until the tornado and prominence erupted into the space that had been opened.Based on these observations, the authors hypothesize that the eruption could be explained using the following model:A tornado and a related solar prominence forms.Magnetic field lines within it are gradually twisted by the tornados rotation, until the tornado becomes unstable to the kink instability (a magnetic instability).The tornado then destabilizes the entire prominence, which expands upwards and erupts into a CME through something known as the magnetic breakout model.If solar tornadoes such as this one generally cause instabilities of prominences, they could be used to predict when a related CME is about to happen providing important information for space weather predictions.CitationIrakli Mghebrishvili et al 2015 ApJ 810 89. doi:10.1088/0004-637X/810/2/89

On forecasting severe storms in Alberta using environmental sounding data

NASA Astrophysics Data System (ADS)

Dupilka, Maxwell L.

Thermodynamic and dynamic parameters computed from observed sounding data are examined to determine whether they can aid in forecasting the potential for severe weather in Alberta. The primary focus is to investigate which sounding parameters can provide probabilistic guidance to distinguish between Significant Tornadoes (F2 to F4), Weak Tornadoes (F0 and F1), and Non-Tornado severe hail storms (≥ 3 cm diameter hail but no reported tornado). The observational data set contains 87 thunderstorm events from 1967 to 2000 within 200 km of Stony Plain, Alberta. Three tornadic thunderstorms with F-scale ratings of F3 and F4 are examined in more detail. A secondary focus is to determine whether sounding data can be used to predict 24 hour snowfall amounts (specifically amounts ≥ 10 cm). Snowfall data covered all of Alberta east of the mountains from October 1990 to April 1993. The major findings were: (a) Significant Tornadoes tended to have stronger environmental bulk wind shear values than Weak Tornadoes or Non-Tornado storms, with a shear magnitude in the 900-500 mb layer exceeding 3 m s-1 km-1. Combining the 900-500 mb shear with the 900-800 mb shear increased the probabilistic guidance for the likelihood of Significant Tornado occurrence. (b) Values of storm-relative helicity showed skill in distinguishing Significant Tornadoes from both Weak Tornadoes and Non-Tornadoes. Significant Tornadoes tended to occur with 0-3 km storm-relative helicity >140 m2 s-2 whereas Weak Tornadoes were typically formed with values between 30 and 150 m 2 s-2. (c) The amount of precipitable water showed statistically significant differences between Significant Tornadoes and the other two groups. Significant Tornadoes had values exceeding 21 mm. Combining precipitable water values with the 900-500 mb shear increased the probabilistic guidance for the potential of Significant Tornadoes. (d) Values of thermal buoyancy, storm convergence, and height of the lifted condensation level provided no skill in discriminating between the three storm categories. (e) The Edmonton tornado case, unlike the Holden and Pine Lake cases, did not feature a prominent synoptic scale moisture front. (f) Observed snowfall amounts showed a roughly linear dependence on the 850 mb temperature, supporting a moisture conservation theory.

Prevention of child injuries during tornadoes: cases from the 2011 tornado outbreak in Alabama.

PubMed

Campbell, Christine M; Baker, Mark D; Monroe, Kathy W

2012-12-01

Tornadoes and violent weather pose a hazard to children, yet little is known about the use of personal protective devices during storms. An outbreak of tornadoes on April 27, 2011, resulted in the deaths of 23 children in Alabama. Records from 60 patients seen in a pediatric emergency department for tornado-related injuries were reviewed to identify the use of injury prevention devices. Three children directly exposed to a violent tornado (Enhanced Fujita Scale 4) were using safety equipment, specifically, a helmet and infant car seats. These 3 children sustained only minor injuries. Personal protective devices may have played a role in preventing child injuries from tornadoes. To our knowledge, this is the first report in the medical literature on helmet and infant car seat use as child protective devices during tornadoes.

Solar Tornadoes Triggered by Interaction between Filaments and EUV Jets

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Huadong; Zhang, Jun; Ma, Suli

We investigate the formations and evolutions of two successive solar tornadoes in/near AR 12297 during 2015 March 19–20. Recurrent EUV jets close to two filaments were detected along a large-scale coronal loop prior to the appearances of the tornadoes. Under the disturbances from the activities, the filaments continually ascended and finally interacted with the loops tracked by the jets. Subsequently, the structures of the filaments and the loop were merged together, probably via magnetic reconnections, and formed tornado-like structures with a long spiral arm. Our observations suggest that solar tornadoes can be triggered by the interaction between filaments and nearbymore » coronal jets, which has rarely been reported before. At the earlier development phase of the first tornado, about 30 small-scale sub-jets appeared in the tornado’s arm, accompanied by local EUV brightenings. They have an ejection direction approximately vertical to the axis of the arm and a typical maximum speed of ∼280 km s{sup −1}. During the ruinations of the two tornadoes, fast plasma outflows from the strong EUV brightenings inside tornadoes are observed, in company with the untangling or unwinding of the highly twisted tornado structures. These observational features indicate that self reconnections probably occurred between the tangled magnetic fields of the tornadoes and resulted in the rapid disintegrations and disappearances of the tornadoes. According to the reconnection theory, we also derive the field strength of the tornado core to be ∼8 G.« less

Solar Tornadoes Triggered by Interaction between Filaments and EUV Jets

NASA Astrophysics Data System (ADS)

Chen, Huadong; Zhang, Jun; Ma, Suli; Yan, Xiaoli; Xue, Jianchao

2017-05-01

We investigate the formations and evolutions of two successive solar tornadoes in/near AR 12297 during 2015 March 19-20. Recurrent EUV jets close to two filaments were detected along a large-scale coronal loop prior to the appearances of the tornadoes. Under the disturbances from the activities, the filaments continually ascended and finally interacted with the loops tracked by the jets. Subsequently, the structures of the filaments and the loop were merged together, probably via magnetic reconnections, and formed tornado-like structures with a long spiral arm. Our observations suggest that solar tornadoes can be triggered by the interaction between filaments and nearby coronal jets, which has rarely been reported before. At the earlier development phase of the first tornado, about 30 small-scale sub-jets appeared in the tornado’s arm, accompanied by local EUV brightenings. They have an ejection direction approximately vertical to the axis of the arm and a typical maximum speed of ˜280 km s-1. During the ruinations of the two tornadoes, fast plasma outflows from the strong EUV brightenings inside tornadoes are observed, in company with the untangling or unwinding of the highly twisted tornado structures. These observational features indicate that self reconnections probably occurred between the tangled magnetic fields of the tornadoes and resulted in the rapid disintegrations and disappearances of the tornadoes. According to the reconnection theory, we also derive the field strength of the tornado core to be ˜8 G.

Numerical Simulation of a Tornado Generating Supercell

NASA Technical Reports Server (NTRS)

Proctor, Fred H.; Ahmad, Nashat N.; LimonDuparcmeur, Fanny M.

2012-01-01

The development of tornadoes from a tornado generating supercell is investigated with a large eddy simulation weather model. Numerical simulations are initialized with a sounding representing the environment of a tornado producing supercell that affected North Carolina and Virginia during the Spring of 2011. The structure of the simulated storm was very similar to that of a classic supercell, and compared favorably to the storm that affected the vicinity of Raleigh, North Carolina. The presence of mid-level moisture was found to be important in determining whether a supercell would generate tornadoes. The simulations generated multiple tornadoes, including cyclonic-anticyclonic pairs. The structure and the evolution of these tornadoes are examined during their lifecycle.

Dynamics and thermodynamics of a tornado: Rotation effects

NASA Astrophysics Data System (ADS)

Ben-Amots, N.

2016-09-01

This paper investigates the relevant processes in the tornado including the dynamics of rotation and thermodynamics as well as condensation. The main novelty of this paper is the explanation of the phenomena occurring in the central downflow. The reduced pressure in the tornado's funnel sucks air and water vapor from the cloud above the tornado. The latent heat of condensation is released in the funnel. The centrifugal force drives the generated water drops out of the funnel. The latent heat of condensation released is also transferred out of the funnel, and supplies the helically ascending air flow surrounding the tornado with additional buoyancy energy. This process gives the tornado increased strength compared to the dust devil type of flow, thus explaining why tornadoes occur always under a cloud, and why the tornado pipe can reach a height of a kilometer and more. To sustain a tornado, the temperature of water vapor at the cloud's base should be higher than the surroundings by a certain minimal value. Remote infrared temperature measurements of clouds' bases may provide indications of the probability that a cloud can spawn a tornado, which may increase the lead time.

A probabilistic tornado wind hazard model for the continental United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hossain, Q; Kimball, J; Mensing, R

A probabilistic tornado wind hazard model for the continental United States (CONUS) is described. The model incorporates both aleatory (random) and epistemic uncertainties associated with quantifying the tornado wind hazard parameters. The temporal occurrences of tornadoes within the continental United States (CONUS) is assumed to be a Poisson process. A spatial distribution of tornado touchdown locations is developed empirically based on the observed historical events within the CONUS. The hazard model is an aerial probability model that takes into consideration the size and orientation of the facility, the length and width of the tornado damage area (idealized as a rectanglemore » and dependent on the tornado intensity scale), wind speed variation within the damage area, tornado intensity classification errors (i.e.,errors in assigning a Fujita intensity scale based on surveyed damage), and the tornado path direction. Epistemic uncertainties in describing the distributions of the aleatory variables are accounted for by using more than one distribution model to describe aleatory variations. The epistemic uncertainties are based on inputs from a panel of experts. A computer program, TORNADO, has been developed incorporating this model; features of this program are also presented.« less

Level 1 Tornado PRA for the High Flux Beam Reactor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bozoki, G.E.; Conrad, C.S.

This report describes a risk analysis primarily directed at providing an estimate for the frequency of tornado induced damage to the core of the High Flux Beam Reactor (HFBR), and thus it constitutes a Level 1 Probabilistic Risk Assessment (PRA) covering tornado induced accident sequences. The basic methodology of the risk analysis was to develop a ``tornado specific`` plant logic model that integrates the internal random hardware failures with failures caused externally by the tornado strike and includes operator errors worsened by the tornado modified environment. The tornado hazard frequency, as well as earlier prepared structural and equipment fragility data,more » were used as input data to the model. To keep modeling/calculational complexity as simple as reasonable a ``bounding`` type, slightly conservative, approach was applied. By a thorough screening process a single dominant initiating event was selected as a representative initiator, defined as: ``Tornado Induced Loss of Offsite Power.`` The frequency of this initiator was determined to be 6.37E-5/year. The safety response of the HFBR facility resulted in a total Conditional Core Damage Probability of .621. Thus, the point estimate of the HFBR`s Tornado Induced Core Damage Frequency (CDF) was found to be: (CDF){sub Tornado} = 3.96E-5/year. This value represents only 7.8% of the internal CDF and thus is considered to be a small contribution to the overall facility risk expressed in terms of total Core Damage Frequency. In addition to providing the estimate of (CDF){sub Tornado}, the report documents, the relative importance of various tornado induced system, component, and operator failures that contribute most to (CDF){sub Tornado}.« less

Modern tornado design of nuclear and other potentially hazardous facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stevenson, J.D.; Zhao, Y.

Tornado wind loads and other tornado phenomena, including tornado missiles and differential pressure effects, have not usually been considered in the design of conventional industrial, commercial, or residential facilities in the United States; however, tornado resistance has often become a design requirement for certain hazardous facilities, such as large nuclear power plants and nuclear materials and waste storage facilities, as well as large liquefied natural gas storage facilities. This article provides a review of current procedures for the design of hazardous industrial facilities to resist tornado effects. 23 refs., 19 figs., 13 tabs.

Examining social, physical, and environmental dimensions of tornado vulnerability in Texas.

PubMed

Siebeneck, Laura

2016-01-01

To develop a vulnerability model that captures the social, physical, and environmental dimensions of tornado vulnerability of Texas counties. Guided by previous research and methodologies proposed in the hazards and emergency management literature, a principle components analysis is used to create a tornado vulnerability index. Data were gathered from open source information available through the US Census Bureau, American Community Surveys, and the Texas Natural Resources Information System. Texas counties. The results of the model yielded three indices that highlight geographic variability of social vulnerability, built environment vulnerability, and tornado hazard throughout Texas. Further analyses suggest that counties with the highest tornado vulnerability include those with high population densities and high tornado risk. This article demonstrates one method for assessing statewide tornado vulnerability and presents how the results of this type of analysis can be applied by emergency managers towards the reduction of tornado vulnerability in their communities.

SOLAR MAGNETIZED 'TORNADOES': RELATION TO FILAMENTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su Yang; Veronig, Astrid; Temmer, Manuela

Solar magnetized 'tornadoes', a phenomenon discovered in the solar atmosphere, appear as tornado-like structures in the corona but are rooted in the photosphere. Like other solar phenomena, solar tornadoes are a feature of magnetized plasma and therefore differ distinctly from terrestrial tornadoes. Here we report the first analysis of solar 'tornadoes' (two papers which focused on different aspects of solar tornadoes were published in the Astrophysical Journal Letters and Nature, respectively, during the revision of this Letter). A detailed case study of two events indicates that they are rotating vertical magnetic structures probably driven by underlying vortex flows in themore » photosphere. They usually exist as a group and are related to filaments/prominences, another important solar phenomenon whose formation and eruption are still mysteries. Solar tornadoes may play a distinct role in the supply of mass and twists to filaments. These findings could lead to a new explanation of filament formation and eruption.« less

Changing volatility of U.S. annual tornado reports

NASA Astrophysics Data System (ADS)

Tippett, Michael K.

2014-10-01

United States (U.S.) tornado activity results in substantial loss of life and property damage each year. A simple measure of the U.S. tornado climatology is the average number of tornadoes per year. However, even this statistic is elusive because of nonstationary behavior due in large part to changes in reporting practices. Differencing of the annual report data results in a quantity without mean trends and whose standard deviation we denote as volatility, since it is an indication of the likely year-to-year variation in the number of tornadoes reported. While volatility changes detected prior to 2000 can be associated with known reporting practice changes, an increase in volatility in the 2000s across intensity levels cannot. A volatility increase is also seen in a tornado environment index which measures the favorability of atmospheric conditions to tornado activity, providing evidence that the recent increase in tornado report volatility is related to the physical environment.

Weather Advisory: Tornados | Poster

Cancer.gov

Summer months carry the threat of severe storms and tornados in our area. Take a few moments to consider how well you are prepared in the event of a tornado warning. The time to prepare for a tornado is before it happens. The Federal Emergency Management Agency (FEMA) provides information on how to prepare and what to do in the event of a tornado. Take a few moments to read

A Statistical Model for Regional Tornado Climate Studies

PubMed Central

Jagger, Thomas H.; Elsner, James B.; Widen, Holly M.

2015-01-01

Tornado reports are locally rare, often clustered, and of variable quality making it difficult to use them directly to describe regional tornado climatology. Here a statistical model is demonstrated that overcomes some of these difficulties and produces a smoothed regional-scale climatology of tornado occurrences. The model is applied to data aggregated at the level of counties. These data include annual population, annual tornado counts and an index of terrain roughness. The model has a term to capture the smoothed frequency relative to the state average. The model is used to examine whether terrain roughness is related to tornado frequency and whether there are differences in tornado activity by County Warning Area (CWA). A key finding is that tornado reports increase by 13% for a two-fold increase in population across Kansas after accounting for improvements in rating procedures. Independent of this relationship, tornadoes have been increasing at an annual rate of 1.9%. Another finding is the pattern of correlated residuals showing more Kansas tornadoes in a corridor of counties running roughly north to south across the west central part of the state consistent with the dryline climatology. The model is significantly improved by adding terrain roughness. The effect amounts to an 18% reduction in the number of tornadoes for every ten meter increase in elevation standard deviation. The model indicates that tornadoes are 51% more likely to occur in counties served by the CWAs of DDC and GID than elsewhere in the state. Flexibility of the model is illustrated by fitting it to data from Illinois, Mississippi, South Dakota, and Ohio. PMID:26244881

A Statistical Model for Regional Tornado Climate Studies.

PubMed

Jagger, Thomas H; Elsner, James B; Widen, Holly M

2015-01-01

Tornado reports are locally rare, often clustered, and of variable quality making it difficult to use them directly to describe regional tornado climatology. Here a statistical model is demonstrated that overcomes some of these difficulties and produces a smoothed regional-scale climatology of tornado occurrences. The model is applied to data aggregated at the level of counties. These data include annual population, annual tornado counts and an index of terrain roughness. The model has a term to capture the smoothed frequency relative to the state average. The model is used to examine whether terrain roughness is related to tornado frequency and whether there are differences in tornado activity by County Warning Area (CWA). A key finding is that tornado reports increase by 13% for a two-fold increase in population across Kansas after accounting for improvements in rating procedures. Independent of this relationship, tornadoes have been increasing at an annual rate of 1.9%. Another finding is the pattern of correlated residuals showing more Kansas tornadoes in a corridor of counties running roughly north to south across the west central part of the state consistent with the dryline climatology. The model is significantly improved by adding terrain roughness. The effect amounts to an 18% reduction in the number of tornadoes for every ten meter increase in elevation standard deviation. The model indicates that tornadoes are 51% more likely to occur in counties served by the CWAs of DDC and GID than elsewhere in the state. Flexibility of the model is illustrated by fitting it to data from Illinois, Mississippi, South Dakota, and Ohio.

Assessing a Tornado Climatology from Global Tornado Intensity Distributions.

NASA Astrophysics Data System (ADS)

Feuerstein, Bernold; Dotzek, Nikolai; Grieser, Jürgen

2005-02-01

Recent work demonstrated that the shape of tornado intensity distributions from various regions worldwide is well described by Weibull functions. This statistical modeling revealed a strong correlation between the fit parameters c for shape and b for scale regardless of the data source. In the present work it is shown that the quality of the Weibull fits is optimized if only tornado reports of F1 and higher intensity are used and that the c-b correlation does indeed reflect a universal feature of the observed tornado intensity distributions. For regions with likely supercell tornado dominance, this feature is the number ratio of F4 to F3 tornado reports R(F4/F3) = 0.238. The c-b diagram for the Weibull shape and scale parameters is used as a climatological chart, which allows different types of tornado climatology to be distinguished, presumably arising from supercell versus nonsupercell tornadogenesis. Assuming temporal invariance of the climatology and using a detection efficiency function for tornado observations, a stationary climatological probability distribution from large tornado records (U.S. decadal data 1950-99) is extracted. This can be used for risk assessment, comparative studies on tornado intensity distributions worldwide, and estimates of the degree of underreporting for areas with poor databases. For the 1990s U.S. data, a likely tornado underreporting of the weak events (F0, F1) by a factor of 2 can be diagnosed, as well as asymptotic climatological c,b values of c = 1.79 and b = 2.13, to which a convergence in the 1950-99 U.S. decadal data is verified.

Characteristics of anvil-top associated with the Poplar Bluff tornado of 7 May 1973

NASA Technical Reports Server (NTRS)

Pearl, E. W.

1973-01-01

Investigation of potential tornado-producing thunderstorms was performed during part of the 1972 and 1973 tornado seasons. On May 7, 1973 twenty-one tornadoes were confirmed over southern Missouri, northern Arkansas, and southwestern Illinois. The region was surveyed by high altitude photography performed on a Learjet over the region of reported tornadoes. Two storms were chosen from aircraft observation with the guidance of ground and radar reports, and a series of photographs were taken of a tornado producing cloud. An analysis of the activity before and during the tornado is made, and most noteworthy were changes detected in the growth and collapse of overshooting domes above the anvil. Suggestions are included for a comprehensive study.

Human holistic and energetic responses following a tornado.

PubMed

Slater, Victoria E

2004-03-01

After an F-4 tornado destroyed a large section of our town, I gave 50 complementary energy treatments to tornado victims. I discovered that the same energetic, physical, emotional, mental, and spiritual disruption occurred in people directly and indirectly exposed to the tornado, and that the damage did not repair spontaneously over time. This article describes the energetic damage people sustained from the tornado and their physical, mental, emotional, and spiritual responses. It also describes the energetic treatment that effectively eliminated the trauma, returning the tornado victim to a stable state. The article concludes with clinical and research implications and relates the treatment of the tornado victims to holistic nursing. The treatment holds promise for victims of posttraumatic stress disorder.

Tornadogenesis Versus Newton's Third Law of Motion

NASA Astrophysics Data System (ADS)

Hardwig, R. B.

2015-12-01

For over 90 years scientists have tried to explain how tornadoes form and function. The present general consensus is that a tornado is just a function of the thunderstorm. Much research has been done to find the answer and numerous articles and papers have been written, all to no avail. This research explores the fact that a tornado cannot be just a function of a thunderstorm, as there is no opposite force within the thunderstorm to the air drawn up by the tornado, so there must be some external force involved in a tornado's formation. To have compliance with Newton's Third Law of Motion we must see an equal downforce or some other force within the thunderstorm, to that drawn up by the tornado. And if there was a downforce, that force would be virtually as damaging as the tornado itself. But we don't see this downforce or any other opposing force within the thunderstorm. Therefore, we must look for some other force that could cause a tornado's formation. And if that opposing force is not within the thunderstorm we need to be looking for some external force, outside the thunderstorm, that could cause a tornado. Also the fact that we have Waterspouts, Landspouts and Gustnadoes all without a thunderstorm, but since they all look and function just like a tornado, tells us that there must be some other force that is responsible for causing a tornado just like a Waterspout, Landspout or Gustnado. My research shows that there is one other force of energy that could cause all of these vortexes and is most likely the source of energy for a tornado's formation. That force is the High Velocity Overhead Jet Stream. My research shows a direct relationship between the High Velocity Overhead Jet Stream and Tornadogenesis as well as Waterspouts, Landspouts and Gustnadoes. Therefore, with the High Velocity Overhead Jet Stream providing the Action, at its interface with the tornado in the stratosphere, the Reaction is what we see on the ground as a tornado. With this explanation we now have compliance with Newton's Third Law of Motion. The Action is the air being entrained, in some way, by the jet stream passing over the top of the tornado and the Reaction is the tornado we see on the ground.

Population influences on tornado reports in the United States

USGS Publications Warehouse

Anderson, C.J.; Wikle, C.K.; Zhou, Q.; Royle, J. Andrew

2007-01-01

The number of tornadoes reported in the United States is believed to be less than the actual incidence of tornadoes, especially prior to the 1990s, because tornadoes may be undetectable by human witnesses in sparsely populated areas and areas in which obstructions limit the line of sight. A hierarchical Bayesian model is used to simultaneously correct for population-based sampling bias and estimate tornado density using historical tornado report data. The expected result is that F2-F5 compared with F0-F1 tornado reports would vary less with population density. The results agree with this hypothesis for the following population centers: Atlanta, Georgia; Champaign, Illinois; and Des Moines, Iowa. However, the results indicated just the opposite in Oklahoma. It is hypothesized that the result is explained by the misclassification of tornadoes that were worthy of F2-F5 rating but were classified as F0-F1 tornadoes, thereby artificially decreasing the number of F2-F5 and increasing the number of F0-F1 reports in rural Oklahoma.

Numerical study of the effects of rotating forced downdraft in reproducing tornado-like vortices

NASA Astrophysics Data System (ADS)

Zhu, Jinwei; Cao, Shuyang; Tamura, Tetsuro; Tokyo Institute of Technology Collaboration; Tongji Univ Collaboration

2016-11-01

Appropriate physical modeling of a tornado-like vortex is a prerequisite to studying near-surface tornado structure and tornado-induced wind loads on structures. Ward-type tornado simulator modeled tornado-like flow by mounting guide vanes around the test area to provide angular momentum to converging flow. Iowa State University, USA modified the Ward-type simulator by locating guide vanes at a high position to allow vertical circulation of flow that creates a rotating forced downdraft in the process of generating a tornado. However, the characteristics of the generated vortices have not been sufficiently investigated till now. In this study, large-eddy simulations were conducted to compare the dynamic vortex structure generated with/without the effect of rotating forced downdraft. The results were also compared with other CFD and experimental results. Particular attention was devoted to the behavior of vortex wander of generated tornado-like vortices. The present study shows that the vortex center wanders more significantly when the rotating forced downdraft is introduced into the flow. The rotating forced downdraft is advantageous for modeling the rear flank downdraft phenomenon of a real tornado.

The human ecology of tornadoes.

PubMed

Aguirre, B E; Saenz, R; Edmiston, J; Yang, N; Agramonte, E; Stuart, D L

1993-11-01

This paper offers an empirical test of the impact of human ecological patterns and other known correlates on tornado occurrence. It uses the National Severe Storms Forecast Center's information on tornadoes from 1950 through 1990 and employs ecological data from the U.S. Bureau of the Census and the Environmental Protection Agency. The results show that metropolitan and other urban counties have higher odds of tornado occurrence than rural counties, and that the probability of occurrence of tornadoes increases with increases in the number of previous tornadoes. The paper assesses the meaning of this finding for demographers, atmospheric scientists, engineers, and disaster managers.

The Atlanta tornado of 1975

NASA Technical Reports Server (NTRS)

Greneker, E. F.; Wilson, C. S.; Metcalf, J. I.

1976-01-01

Joint observations by radar and high-frequency sferics detectors at Georgia Institute of Technology provided unique data on the Atlanta tornado of Mar. 24, 1975. The classic hook echo was detected by radar at a range of about 26 km, 15 min before the tornado touched down. While the tornado was on the ground the sferics burst rate was very low, despite very high values recorded immediately before and after this interval. This observation, together with visual reports of a strong cloud-to-ground discharge at the time of tornado touchdown, suggests an interaction of the tornado with the electric field of the storm.

The Tornado.

ERIC Educational Resources Information Center

Snow, John T.

1984-01-01

Although tornadoes have been one of the most elusive phenomena in meteorology, new observation techniques are now revealing how they are spawned by thunderstorms. Tornado structure and formation, thunderstorms, tornadic thunderstorms, and the evolution and structure of such thunderstorms are considered. Why the Midwest has frequent tornadoes is…

More tornadoes in the most extreme U.S. tornado outbreaks

NASA Astrophysics Data System (ADS)

Tippett, Michael K.; Lepore, Chiara; Cohen, Joel E.

2016-12-01

Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion (US). The largest U.S. effects of tornadoes result from tornado outbreaks, which are sequences of tornadoes that occur in close succession. Here, using extreme value analysis, we find that the frequency of U.S. outbreaks with many tornadoes is increasing and that it is increasing faster for more extreme outbreaks. We model this behavior by extreme value distributions with parameters that are linear functions of time or of some indicators of multidecadal climatic variability. Extreme meteorological environments associated with severe thunderstorms show consistent upward trends, but the trends do not resemble those currently expected to result from global warming.

On the Environment of Supercells That Produce Anticyclonic-Cyclonic Tornado Pairs

NASA Astrophysics Data System (ADS)

Bluestein, H. B.; Snyder, J.; Houser, J.

2015-12-01

Anticyclonic tornadoes in supercells are very rare events, which have been documented in anticyclonically rotating, left-moving supercells in the Northern Hemisphere. It is well known that anticyclonic supercells, which can spawn anticyclonic tornadoes, form in an environment in which the vertical shear vector turns in a counterclockwise manner with height. Less rare, however, are anticyclonic tornadoes that appear in cyclonically rotating, right-moving supercells. When these anticyclonic tornadoes have been documented, they have occurred in tandem with a cyclonic tornado or intense mesocyclone. In this talk we will present Doppler radar documentation and photographs and videos of anticyclonic-cyclonic tornado pairs. We will then describe the environmental conditions under which they occur, with emphasis on any special conditions that observationally seem to favor their development.

Genesis of tornadoes associated with hurricanes

NASA Technical Reports Server (NTRS)

Gentry, R. C.

1983-01-01

The climatological history of hurricane-tornadoes is brought up to date through 1982. Most of the tornadoes either form near the center of the hurricane, from the outer edge of the eyewall outward, or in an area between north and east-southeast of the hurricane center. The blackbody temperatures of the cloud tops which were analyzed for several hurricane-tornadoes that formed in the years 1974, 1975, and 1979, did not furnish strong precursor signals of tornado formation, but followed one of two patterns: either the temperatures were very low, or the tornado formed in areas of strong temperature gradients. Tornadoes with tropical cyclones most frequently occur at 1200-1800 LST, and although most are relatively weak, they can reach the F3 intensity level. Most form in association with the outer rainbands of the hurricane.

Development of a Probabilistic Tornado Wind Hazard Model for the Continental United States Volume I: Main Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boissonnade, A; Hossain, Q; Kimball, J

Since the mid-l980's, assessment of the wind and tornado risks at the Department of Energy (DOE) high and moderate hazard facilities has been based on the straight wind/tornado hazard curves given in UCRL-53526 (Coats, 1985). These curves were developed using a methodology that utilized a model, developed by McDonald, for severe winds at sub-tornado wind speeds and a separate model, developed by Fujita, for tornado wind speeds. For DOE sites not covered in UCRL-53526, wind and tornado hazard assessments are based on the criteria outlined in DOE-STD-1023-95 (DOE, 1996), utilizing the methodology in UCRL-53526; Subsequent to the publication of UCRL53526,more » in a study sponsored by the Nuclear Regulatory Commission (NRC), the Pacific Northwest Laboratory developed tornado wind hazard curves for the contiguous United States, NUREG/CR-4461 (Ramsdell, 1986). Because of the different modeling assumptions and underlying data used to develop the tornado wind information, the wind speeds at specified exceedance levels, at a given location, based on the methodology in UCRL-53526, are different than those based on the methodology in NUREG/CR-4461. In 1997, Lawrence Livermore National Laboratory (LLNL) was funded by the DOE to review the current methodologies for characterizing tornado wind hazards and to develop a state-of-the-art wind/tornado characterization methodology based on probabilistic hazard assessment techniques and current historical wind data. This report describes the process of developing the methodology and the database of relevant tornado information needed to implement the methodology. It also presents the tornado wind hazard curves obtained from the application of the method to DOE sites throughout the contiguous United States.« less

Doppler Radar and Lightning Network Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

NASA Technical Reports Server (NTRS)

Mccaul, Eugene W., Jr.; Buechler, Dennis E.; Goodman, Steven J.; Cammarata, Michael

2004-01-01

Data from a single Weather Surveillance Radar-1988 Doppler (WSR-88D) and the National Lightning Detection Network are used to examine the characteristics of the convective storms that produced a severe tornado outbreak, including three tornadoes that reached F3 intensity, within Tropical Storm Beryl s remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 13 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 h. spawning tornadoes over a time period spanning approximately 6.5 h. Several other tornadic cells also exhibited great longevity, with cell lifetimes longer than ever previously documented in a landfalling tropical cyclone (TC) tornado event. This event is easily the most intense TC tornado outbreak yet documented with WSR-88Ds. Time-height analyses of the three strongest tornadic supercells are presented in order to document storm kinematic structure and to show how these storms appear at different ranges from a WSR-88D. In addition, cloud-to-ground (CG) lightning data are examined in Beryl s remnants. Although the tornadic cells were responsible for most of Beryl's CG lightning, their flash rates were only weak to moderate, and in all the tornadic storms the lightning flashes were almost entirely negative in polarity. A few of the single-tornado storms produced no detectable CG lightning at all. There is evidence that CG lightning rates decreased during the tornadoes, compared to 30-min periods before the tornadoes. A number of the storms spawned tornadoes just after producing their final CG lightning flashes. Contrary to the findings for flash rates, both peak currents and positive flash percentages were larger in Beryl's nontornadic storms than in the tornadic ones.

Dual-Polarimetric Radar-Based Tornado Debris Signatures and Paths Associated with Tornadoes Over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Christopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Jedloved, Gary J.; Carcione, Brian C.; Darden, Christopher B.;

The environment associated with significant tornadoes in Bangladesh

NASA Astrophysics Data System (ADS)

Bikos, Dan; Finch, Jonathan; Case, Jonathan L.

2016-01-01

This paper investigates the environmental parameters favoring significant tornadoes in Bangladesh through a simulation of ten high-impact events. A climatological perspective is first presented on classifying significant tornadoes in Bangladesh, noting the challenges since reports of tornadoes are not documented in a formal manner. The statistical relationship between United States and Bangladesh tornado-related deaths suggests that significant tornadoes do occur in Bangladesh so this paper identifies the most significant tornadic events and analyzes the environmental conditions associated with these events. Given the scarcity of observational data to assess the near-storm environment in this region, high-resolution (3-km horizontal grid spacing) numerical weather prediction simulations are performed for events identified to be associated with a significant tornado. In comparison to similar events over the United States, significant tornado environments in Bangladesh are characterized by relatively high convective available potential energy, sufficient deep-layer vertical shear, and a propensity for deviant (i.e., well to the right of the mean flow) storm motion along a low-level convergence boundary.

Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity.

PubMed

Tippett, Michael K; Cohen, Joel E

2016-02-29

Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from 'outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related.

Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity

PubMed Central

Tippett, Michael K.; Cohen, Joel E.

2016-01-01

Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from ‘outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954–2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related. PMID:26923210

Tornado outbreak variability follows Taylor's power law of fluctuation scaling and increases dramatically with severity

NASA Astrophysics Data System (ADS)

Tippett, Michael K.; Cohen, Joel E.

2016-02-01

Tornadoes cause loss of life and damage to property each year in the United States and around the world. The largest impacts come from `outbreaks' consisting of multiple tornadoes closely spaced in time. Here we find an upward trend in the annual mean number of tornadoes per US tornado outbreak for the period 1954-2014. Moreover, the variance of this quantity is increasing more than four times as fast as the mean. The mean and variance of the number of tornadoes per outbreak vary according to Taylor's power law of fluctuation scaling (TL), with parameters that are consistent with multiplicative growth. Tornado-related atmospheric proxies show similar power-law scaling and multiplicative growth. Path-length-integrated tornado outbreak intensity also follows TL, but with parameters consistent with sampling variability. The observed TL power-law scaling of outbreak severity means that extreme outbreaks are more frequent than would be expected if mean and variance were independent or linearly related.

A statistical analysis of the association between tropical cyclone intensity change and tornado frequency

NASA Astrophysics Data System (ADS)

Moore, Todd W.

2016-07-01

Tropical cyclones often produce tornadoes that have the potential to compound the injury and fatality counts and the economic losses associated with tropical cyclones. These tornadoes do not occur uniformly through time or across space. Multiple statistical methods were used in this study to analyze the association between tropical cyclone intensity change and tornado frequency. Results indicate that there is an association between the two and that tropical cyclones tend to produce more tornadoes when they are weakening, but the association is weak. Tropical cyclones can also produce a substantial number of tornadoes when they are relatively stable or strengthening.

Comment on "Eliminating the major tornado threat in Tornado Alley"

NASA Astrophysics Data System (ADS)

Dahl, Johannes M. L.; Markowski, Paul M.

2014-11-01

The authors draw from half a century of meteorological research to expose flaws in a recent proposal to build 300-m-tall tornado-prevention walls across the U.S. Great Plains. The idea behind the walls is that they would prevent cold and warm air masses from clashing and would therefore suppress tornadoes. The problem with this proposal, however, is that atmospheric fronts ("airmass clashes") are neither a necessary nor a sufficient condition for tornadoes and that the proposed walls would not prevent the formation of fronts in the first place. Additional misconceptions about supercells thunderstorms and tornado formation also are identified.

Weather Advisory: Tornados | Poster

Cancer.gov

Summer months carry the threat of severe storms and tornados in our area. Take a few moments to consider how well you are prepared in the event of a tornado warning. The time to prepare for a tornado is before it happens. The Federal Emergency Management Agency (FEMA) provides information on how to prepare and what to do in the event of a tornado. Take a few moments to read the important safety information FEMA has assembled: http://www.ready.gov/tornadoes. Sign Up for Text Alerts from Frederick County You can also sign up for text alerts to your cell phone from Frederick County at http://www.frederickcountymd.gov/ALERT.

Near-ground tornado wind fields

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, J.R.

1984-07-01

A study of near-ground tornado wind fields has been conducted by inspecting damage and debris patterns found in tornado damage paths. Because there were no significant tornado events (F4 or greater) during the contract performance period, data from the literature and the files of the Institute for Disaster Research were used to perform the analyses. The results indicate: (1) maximum tornado wind speed ever experienced or expected is in the range of 250 to 300 mph; (2) appearance of damage, taken by itself, is a misleading parameter of tornado intensity. Type of construction, age of construction, materials and other constructionmore » features significantly affect structural performance of a building subjected to wind loads and should be taken into account in assigning Fujita-Scale ratings; (3) damage to forests gives a good indication of tornado wind field flow patterns, but do not give verifiable values of wind speed; (4) factors such as translational speed, wind direction and path width affect appearance of damage or a tornado; and (5) even the most awesome appearing missiles do not require incredible wind speeds to explain them. Some progress in computer simulation of tornado missiles have been made. 31 references, 8 figures, 2 tables.« less

What's Left After a Tornado.

ERIC Educational Resources Information Center

Lawrence Inst. of Tech., Southfield, MI.

Following recent tornadoes, terms of specially trained architectural and engineering faculty conducted onsite examinations and research of building damage. It was concluded that tornado damage to buildings is predictable. A trained architect or engineer can establish, before a tornado strikes, those portions of the building that will offer the…

Performance Analysis of the United States Marine Corps War Reserve Materiel Program Process Flow

DTIC Science & Technology

2016-12-01

or Less)............41 Figure 21. Tornado Diagram of Expected Delays Using 2016 Inputs ........................42 x Figure 22. Fishbone Diagram of...variability. Using Crystal Ball we produced a Tornado Diagram (similar to a Pareto Chart) in order to tell us where to focus our efforts. The results of...the Tornado Diagram are shown in Figure 21. Figure 21. Tornado Diagram of Expected Delays Using 2016 Inputs Using the results shown in the Tornado

Statistical Models for Tornado Climatology: Long and Short-Term Views.

PubMed

Elsner, James B; Jagger, Thomas H; Fricker, Tyler

2016-01-01

This paper estimates regional tornado risk from records of past events using statistical models. First, a spatial model is fit to the tornado counts aggregated in counties with terms that control for changes in observational practices over time. Results provide a long-term view of risk that delineates the main tornado corridors in the United States where the expected annual rate exceeds two tornadoes per 10,000 square km. A few counties in the Texas Panhandle and central Kansas have annual rates that exceed four tornadoes per 10,000 square km. Refitting the model after removing the least damaging tornadoes from the data (EF0) produces a similar map but with the greatest tornado risk shifted south and eastward. Second, a space-time model is fit to the counts aggregated in raster cells with terms that control for changes in climate factors. Results provide a short-term view of risk. The short-term view identifies a shift of tornado activity away from the Ohio Valley under El Niño conditions and away from the Southeast under positive North Atlantic oscillation conditions. The combined predictor effects on the local rates is quantified by fitting the model after leaving out the year to be predicted from the data. The models provide state-of-the-art views of tornado risk that can be used by government agencies, the insurance industry, and the general public.

Statistical Models for Tornado Climatology: Long and Short-Term Views

PubMed Central

Jagger, Thomas H.; Fricker, Tyler

2016-01-01

This paper estimates regional tornado risk from records of past events using statistical models. First, a spatial model is fit to the tornado counts aggregated in counties with terms that control for changes in observational practices over time. Results provide a long-term view of risk that delineates the main tornado corridors in the United States where the expected annual rate exceeds two tornadoes per 10,000 square km. A few counties in the Texas Panhandle and central Kansas have annual rates that exceed four tornadoes per 10,000 square km. Refitting the model after removing the least damaging tornadoes from the data (EF0) produces a similar map but with the greatest tornado risk shifted south and eastward. Second, a space-time model is fit to the counts aggregated in raster cells with terms that control for changes in climate factors. Results provide a short-term view of risk. The short-term view identifies a shift of tornado activity away from the Ohio Valley under El Niño conditions and away from the Southeast under positive North Atlantic oscillation conditions. The combined predictor effects on the local rates is quantified by fitting the model after leaving out the year to be predicted from the data. The models provide state-of-the-art views of tornado risk that can be used by government agencies, the insurance industry, and the general public. PMID:27875581

Get off the bus: sound strategy for injury prevention during a tornado?

PubMed

Comstock, R Dawn; Mallonee, Sue

2005-01-01

On 08 May 2003, a tornado categorized as an F-3 on the Fujita Tornado Scale (the "F Scale") struck an Oklahoma City, Oklahoma commuter bus carrying 24 passengers. The driver evacuated several passengers before the tornado struck. The tornado rolled the bus, and pelted it with debris. A case-series investigation of tornado-related injuries was conducted among passengers who were evacuated to a ditch and those who remained on the bus when the tornado struck. Nineteen of 24 passengers sought care for injuries at hospital emergency departments (injury rate = 79.2%). While a greater number of passengers who were outside the bus when the tornado struck (11) sought care for injuries than did those who remained on the bus (8); passengers outside of the bus suffered fewer injuries than did those who remained on the bus (median number of injuries 3 versus 4), and their injuries were less severe (median injury severity score (ISS) 1 versus 4). For persons caught in motor vehicles during tornado events, this study supports currently accepted recommendations to immediately evacuate and lie in a low-lying area away from motor vehicles if other shelter is unavailable. However, generalizing the experience of bus passengers to automobile drivers might be inappropriate because buses lack the safety features that might protect automobile drivers from tornado-related injuries.

More tornadoes in the most extreme U.S. tornado outbreaks.

PubMed

Tippett, Michael K; Lepore, Chiara; Cohen, Joel E

2016-12-16

Tornadoes and severe thunderstorms kill people and damage property every year. Estimated U.S. insured losses due to severe thunderstorms in the first half of 2016 were $8.5 billion (US). The largest U.S. effects of tornadoes result from tornado outbreaks, which are sequences of tornadoes that occur in close succession. Here, using extreme value analysis, we find that the frequency of U.S. outbreaks with many tornadoes is increasing and that it is increasing faster for more extreme outbreaks. We model this behavior by extreme value distributions with parameters that are linear functions of time or of some indicators of multidecadal climatic variability. Extreme meteorological environments associated with severe thunderstorms show consistent upward trends, but the trends do not resemble those currently expected to result from global warming. Copyright © 2016, American Association for the Advancement of Science.

Tornado and extreme wind design criteria for nuclear power plants

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

1973-12-01

Nuclear power plant design criteria for tornadoes and extreme winds are presented. Data, formulas, and procedures for determining maximum wind loading on structures and parts of structures are included. Extreme wind loading is applied to structures using methods and procedures consistent with ANSI Building Code A58.1- 1972. The design wind velocities specified generally exceed 100-year recurrent interval winds. Tornado wind loading is applied to structures using procedures paralleling those for extrene winds with additional criteria resulting from the atmospheric pressure change accompanying tornadoes and tornado missile inipact effects. Tornado loading for the 48 contiguous United States is specified for twomore » major zones separated by the Continental Divide. A cross reference listing items related to Atomic Energy Commission Safety Analysis Report format is provided. Development supporting tornado criteria is included. (auth)« less

April 23, 1983 tornado at the Savannah River Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Garrett, A.J.

1983-07-01

Just before 8:00 p.m. on Saturday, April 23, 1983, a small (Fl) tornado touched ground in Jackson, South Carolina and traveled northeast for several miles, passing just northwest of the SRP 700-A Area. The tornado uprooted or snapped many large trees in Jackson, and damaged several homes and buildings, including the loss of an entire roof from one store. After it passed through Jackson, the tornado damaged pine forests on the SRP border. Based on the Fujita tornado intensity scale and observed damage, the maximum winds in the tornado were probably 100 to 150 mph. Several swaths in the forestedmore » area, each several hundred yards long, were almost denuded (80 to 90% uprooting or snapping of trees). As the tornado approached A Area, it appeared to be weakening, with maximum tree losses of 30 to 50%. The A-Area meteorological tower measured winds of 62 mph before the wind sensor was blown off the tower. Damage to A Area was small, although several trailers lost windows and pieces of roofing, one trailer was overturned, and at least one small shed was demolished. The tornado continued to the northeast where it died out over the SRP forest after felling trees for several more miles. Inspection of the rest of the SRP site from a helicopter showed that no other tornados hit SRP during the April 23 storm, although other tornados hit parts of South Carolina and Georgia. It was the first known occurrence of a tornado at SRP since 1976.« less

ARE GIANT TORNADOES THE LEGS OF SOLAR PROMINENCES?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wedemeyer, Sven; Scullion, Eamon; Rouppe van der Voort, Luc

Observations in the 171 A channel of the Atmospheric Imaging Assembly of the space-borne Solar Dynamics Observatory show tornado-like features in the atmosphere of the Sun. These giant tornadoes appear as dark, elongated, and apparently rotating structures in front of a brighter background. This phenomenon is thought to be produced by rotating magnetic field structures that extend throughout the atmosphere. We characterize giant tornadoes through a statistical analysis of properties such as spatial distribution, lifetimes, and sizes. A total number of 201 giant tornadoes are detected in a period of 25 days, suggesting that, on average, about 30 events aremore » present across the whole Sun at a time close to solar maximum. Most tornadoes appear in groups and seem to form the legs of prominences, thus serving as plasma sources/sinks. Additional H{alpha} observations with the Swedish 1 m Solar Telescope imply that giant tornadoes rotate as a structure, although they clearly exhibit a thread-like structure. We observe tornado groups that grow prior to the eruption of the connected prominence. The rotation of the tornadoes may progressively twist the magnetic structure of the prominence until it becomes unstable and erupts. Finally, we investigate the potential relation of giant tornadoes to other phenomena, which may also be produced by rotating magnetic field structures. A comparison to cyclones, magnetic tornadoes, and spicules implies that such events are more abundant and short-lived the smaller they are. This comparison might help to construct a power law for the effective atmospheric heating contribution as a function of spatial scale.« less

Pre-Post Tornado Effects on Aggressive Children's Psychological and Behavioral Adjustment Through One-Year Postdisaster.

PubMed

Lochman, John E; Vernberg, Eric; Powell, Nicole P; Boxmeyer, Caroline L; Jarrett, Matthew; McDonald, Kristina; Qu, Lixin; Hendrickson, Michelle; Kassing, Francesca

2017-01-01

Using a risk-resilience framework, this study examined how varying levels of exposure to a natural disaster (EF-4 tornado) and children's characteristics (sex; anxiety) influenced the behavioral and psychological adjustment of children who shared a common risk factor predisaster (elevated aggression) prior to exposure through 1-year postdisaster. Participants included 360 children in Grades 4-6 (65% male; 78% African American) and their parents from predominantly low-income households who were already participating in a longitudinal study of indicated prevention effects for externalizing outcomes when the tornado occurred in 2011. Fourth-grade children who were screened for overt aggressive behavior were recruited in 3 annual cohorts (120 per year, beginning in 2009). Parent-rated aggression and internalizing problems were assessed prior to the tornado (Wave 1), within a half-year after the tornado (Wave 2), and at a 1-year follow-up (Wave 3). Children and parents rated their exposure to aspects of tornado-related traumatic experiences at Wave 3. Children displayed less reduction on aggression and internalizing problems if the children had experienced distress after the tornado or fears for their life, in combination with their pre-tornado level of anxiety. Higher levels of children's and parents' exposure to the tornado interacted with children's lower baseline child anxiety to predict less reduction in aggression and internalizing problems 1 year after the tornado. Higher levels of disaster exposure negatively affected at-risk children's level of improvement in aggression and internalizing problems, when life threat (parent- and child-reported) and child-reported distress after the tornado were moderated by baseline anxiety.

Are Giant Tornadoes the Legs of Solar Prominences?

NASA Astrophysics Data System (ADS)

Wedemeyer, Sven; Scullion, Eamon; Rouppe van der Voort, Luc; Bosnjak, Antonija; Antolin, Patrick

2013-09-01

Observations in the 171 Å channel of the Atmospheric Imaging Assembly of the space-borne Solar Dynamics Observatory show tornado-like features in the atmosphere of the Sun. These giant tornadoes appear as dark, elongated, and apparently rotating structures in front of a brighter background. This phenomenon is thought to be produced by rotating magnetic field structures that extend throughout the atmosphere. We characterize giant tornadoes through a statistical analysis of properties such as spatial distribution, lifetimes, and sizes. A total number of 201 giant tornadoes are detected in a period of 25 days, suggesting that, on average, about 30 events are present across the whole Sun at a time close to solar maximum. Most tornadoes appear in groups and seem to form the legs of prominences, thus serving as plasma sources/sinks. Additional Hα observations with the Swedish 1 m Solar Telescope imply that giant tornadoes rotate as a structure, although they clearly exhibit a thread-like structure. We observe tornado groups that grow prior to the eruption of the connected prominence. The rotation of the tornadoes may progressively twist the magnetic structure of the prominence until it becomes unstable and erupts. Finally, we investigate the potential relation of giant tornadoes to other phenomena, which may also be produced by rotating magnetic field structures. A comparison to cyclones, magnetic tornadoes, and spicules implies that such events are more abundant and short-lived the smaller they are. This comparison might help to construct a power law for the effective atmospheric heating contribution as a function of spatial scale.

Probabilistic wind/tornado/missile analyses for hazard and fragility evaluations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Y.J.; Reich, M.

Detailed analysis procedures and examples are presented for the probabilistic evaluation of hazard and fragility against high wind, tornado, and tornado-generated missiles. In the tornado hazard analysis, existing risk models are modified to incorporate various uncertainties including modeling errors. A significant feature of this paper is the detailed description of the Monte-Carlo simulation analyses of tornado-generated missiles. A simulation procedure, which includes the wind field modeling, missile injection, solution of flight equations, and missile impact analysis, is described with application examples.

Tornado disaster -- Texas, May 1997.

PubMed

1997-11-14

On May 27, 1997, multiple tornadoes swept through Williamson and Travis counties in central Texas. The tornadoes caused 32 injuries, 29 deaths, and an estimated $20 million in personal and commercial insured losses. This report summarizes the injuries and deaths associated with these tornadoes based on information from emergency department and hospital records and death certificates.

Annihilation and Reanimation of a Tornado in the Improved Tornado Tube

ERIC Educational Resources Information Center

Bednarek, Stanislaw

2016-01-01

Some new experiments using an improved version of the "tornado tube" are described here. The improved tornado tube consists of two plastic transparent bottles whose openings are connected with a ball valve, available at most hardware stores. After being filled with fluid and inverting, this tube allows demonstration of the generation,…

Conceptions of Tornado Wind Speed and Land Surface Interactions among Undergraduate Students in Nebraska

ERIC Educational Resources Information Center

Van Den Broeke, Matthew S.; Arthurs, Leilani

2015-01-01

To ascertain novice conceptions of tornado wind speed and the influence of surface characteristics on tornado occurrence, 613 undergraduate students enrolled in introductory science courses at a large state university in Nebraska were surveyed. Our findings show that students lack understanding of the fundamental concepts that (1) tornadoes are…

Health Information in Modern Standard Arabic (al-ʻArabīyat ul-fuṣḥá)

MedlinePlus

... fuṣḥá (Modern Standard Arabic) MP4 Healthy Roads Media Tornadoes - English MP3 Tornadoes - al-ʻArabīyat ul-fuṣḥá (Modern Standard Arabic) MP3 Tornadoes - English MP4 Tornadoes - al-ʻArabīyat ul-fuṣḥá (Modern ...

Science 101: What Causes Severe Thunderstorms and Tornadoes?

ERIC Educational Resources Information Center

Robertson, Bill

2016-01-01

What causes severe thunderstorms and tornadoes? Tornadoes, often accompanied by severe thunderstorms and hail, form in pretty much the same way as severe thunderstorms. In the continental United States, tornadoes usually form in spring and summer, when warm, humid air from the Gulf of Mexico moves across the continent from southeast to northwest…

The recollective qualities of adolescents' and adults' narratives about a long-ago tornado.

PubMed

Bauer, Patricia J; Stark, Emily N; Ackil, Jennifer K; Larkina, Marina; Merrill, Natalie; Fivush, Robyn

2017-03-01

The recollective qualities of autobiographical memory are thought to develop over the course of the first two decades of life. We used a 9-year follow-up test of recall of a devastating tornado and of non-tornado-related events from before and after the storm, to compare the recollective qualities of adolescents' (n = 20, ages 11 years, 11 months to 20 years, 8 months) and adults' (n = 14) autobiographical memories. At the time of the tornado, half of the adolescents had been younger than age 6. Nine years after the event, all participants provided evidence that they recall the event of the tornado. Adults also had high levels of recall of the non-tornado-related events. Adolescents recalled proportionally fewer non-tornado-related events; adolescents younger than 6 at the time of the events recalled the fewest non-tornado-related events. Relative to adolescents, adults produced longer narratives. With narrative length controlled, there were few differences in the recollective qualities of adolescents' and adults' narrative reports, especially in the case of the tornado; the recollective qualities were stronger among adolescents older at the time of the events. Overall, participants in both age groups provided evidence of the qualities of recollection that are characteristic of autobiographical memory.

Daily variation in natural disaster casualties: information flows, safety, and opportunity costs in tornado versus hurricane strikes.

PubMed

Zahran, Sammy; Tavani, Daniele; Weiler, Stephan

2013-07-01

Casualties from natural disasters may depend on the day of the week they strike. With data from the Spatial Hazard Events and Losses Database for the United States (SHELDUS), daily variation in hurricane and tornado casualties from 5,043 tornado and 2,455 hurricane time/place events is analyzed. Hurricane forecasts provide at-risk populations with considerable lead time. Such lead time allows strategic behavior in choosing protective measures under hurricane threat; opportunity costs in terms of lost income are higher during weekdays than during weekends. On the other hand, the lead time provided by tornadoes is near zero; hence tornados generate no opportunity costs. Tornado casualties are related to risk information flows, which are higher during workdays than during leisure periods, and are related to sheltering-in-place opportunities, which are better in permanent buildings like businesses and schools. Consistent with theoretical expectations, random effects negative binomial regression results indicate that tornado events occurring on the workdays of Monday through Thursday are significantly less lethal than tornados that occur on weekends. In direct contrast, and also consistent with theory, the expected count of hurricane casualties increases significantly with weekday occurrences. The policy implications of observed daily variation in tornado and hurricane events are considered. © 2012 Society for Risk Analysis.

Risk factors for death or injury in tornadoes: An epidemiologic approach

NASA Astrophysics Data System (ADS)

Brenner, Sue Anne; Noji, Eric K.

On August 28, 1990, between 3:15 and 3:45 P.M., a tornado beat a path of destruction through the Will County, Illinois, towns of Plainfield, Crest Hill, and Joliet [National Weather Service, 1991]. The parent severe thunderstorm formed on the Illinois-Wisconsin border and moved southeastward across northeast Illinois. Over its 4-hour lifetime it produced several other less damaging tornadoes, as well as large hail and strong straight line winds. The Plainfield tornado was rated as an F-5 tornado, with a path length of 16.5 mi (0.62 mi = 1 km) and path width of 700 yd (1.09 yd = 1 m). No tornado warning was issued by the National Weather Service. It was the worst tornado in Illinois in more than 20 years and one of the most violent in U.S. history. The tornado severed electrical power to 65,000 homes and businesses, cut off phone service to 10,000 residences, and caused more than $200 million worth of damage. When the tornado hit, few people were in a protected area such as the basement or inner area of a house. As a result of the storm's impact, 302 people were injured, including 80 persons who were hospitalized and survived and 28 who died.

Annual and seasonal tornado activity in the United States and the global wind oscillation

NASA Astrophysics Data System (ADS)

Moore, Todd W.

2018-06-01

Previous studies have searched for relationships between tornado activity and atmospheric teleconnections to provide insight on the relationship between tornadoes, their environments, and larger scale patterns in the climate system. Knowledge of these relationships is practical because it can improve seasonal and sub-seasonal predictions of tornado probability and, therefore, help mitigate tornado-related losses. This study explores the relationships between the annual and seasonal tornado activity in the United States and the Global Wind Oscillation. Time series herein show that phases of the Global Wind Oscillation, and atmospheric angular momentum anomalies, vary over a period of roughly 20-25 years. Rank correlations indicate that tornado activity is weakly correlated with phases 2, 3, and 4 (positive) and 6, 7, and 8 (negative) of the Global Wind Oscillation in winter, spring, and fall. The correlation is not as clear in summer or at the annual scale. Non-parametric Mann-Whitney U tests indicate that winters and springs with more phase 2, 3, and 4 and fewer phase 6, 7, and 8 days tend to have more tornadoes. Lastly, logistic regression models indicate that winters and springs with more phase 2, 3, and 4 days have greater likelihoods of having more than normal tornado activity. Combined, these analyses suggest that seasons with more low atmospheric angular momentum days, or phase 2, 3, and 4 days, tend to have greater tornado activity than those with fewer days, and that this relationship is most evident in winter and spring.

A forensic re-analysis of one of the deadliest European tornadoes

NASA Astrophysics Data System (ADS)

Holzer, Alois M.; Schreiner, Thomas M. E.; Púčik, Tomáš

2018-06-01

Extremely rare events with high potential impact, such as violent tornadoes, are of strong interest for climatology and risk assessment. In order to obtain more knowledge about the most extreme events, it is vital to study historical cases. The purpose of this paper is twofold: (1) to demonstrate how a windstorm catastrophe that happened 100 years ago, such as the Wiener Neustadt, Lower Austria, tornado on 10 July 1916, can be successfully re-analyzed using a forensic approach, and (2) to propose a repeatable working method for assessing damage and reconstructing the path and magnitude of local windstorm and tornado cases with sufficient historical sources. Based on the results of the forensic re-analyses, a chronology of the tornado impact is presented, followed by a description of the key tornado characteristics: a maximum intensity rating of F4, a damage path length of 20 km and a maximum visible tornado diameter of 1 km. Compared to a historical scientific study published soon after the event, additional new findings are presented, namely the existence of two predecessor tornadoes and a higher number of fatalities: at least 34 instead of 32. While the storm-scale meteorology could not be reconstructed, rich damage data sources for the urban area of Wiener Neustadt facilitated a detailed analysis of damage tracks and wind intensities within the tornado. The authors postulate the requirement for an International Fujita Scale to rate tornadoes globally in a consistent way, based on comparable damage indicators.

Annual and seasonal tornado activity in the United States and the global wind oscillation

NASA Astrophysics Data System (ADS)

Moore, Todd W.

2017-08-01

Previous studies have searched for relationships between tornado activity and atmospheric teleconnections to provide insight on the relationship between tornadoes, their environments, and larger scale patterns in the climate system. Knowledge of these relationships is practical because it can improve seasonal and sub-seasonal predictions of tornado probability and, therefore, help mitigate tornado-related losses. This study explores the relationships between the annual and seasonal tornado activity in the United States and the Global Wind Oscillation. Time series herein show that phases of the Global Wind Oscillation, and atmospheric angular momentum anomalies, vary over a period of roughly 20-25 years. Rank correlations indicate that tornado activity is weakly correlated with phases 2, 3, and 4 (positive) and 6, 7, and 8 (negative) of the Global Wind Oscillation in winter, spring, and fall. The correlation is not as clear in summer or at the annual scale. Non-parametric Mann-Whitney U tests indicate that winters and springs with more phase 2, 3, and 4 and fewer phase 6, 7, and 8 days tend to have more tornadoes. Lastly, logistic regression models indicate that winters and springs with more phase 2, 3, and 4 days have greater likelihoods of having more than normal tornado activity. Combined, these analyses suggest that seasons with more low atmospheric angular momentum days, or phase 2, 3, and 4 days, tend to have greater tornado activity than those with fewer days, and that this relationship is most evident in winter and spring.

Tornado-related fatalities--five states, Southeastern United States, April 25-28, 2011.

PubMed

2012-07-20

During April 25-28, 2011, a massive storm system generated 351 tornadoes (including 15 registering 4 or 5 on the Enhanced Fujita [EF] scale*), killing 338 persons in Alabama, Arkansas, Georgia, Mississippi, and Tennessee. This was the third-deadliest tornado event in the United States, surpassing an April 1974 event that resulted in 315 fatalities. This event also was historic because of the record number of fatalities that occurred despite modern advances in tornado forecasting, advanced warning times, and media coverage. Risk factors for death and injury from tornadoes are sheltering in mobile homes, proximity to an EF-4 or EF-5 tornado, being an older adult (aged ≥65 years), lack of accessibility to safe rooms (e.g., basements or reinforced shelters), and a night-time tornado impact. To describe the fatalities by demographic characteristics, type of shelter used, cause of death, and tornado severity and location, CDC reviewed data from the American Red Cross (Red Cross), death certificates, and the National Weather Service (NWS). This report summarizes the results of that review. Among the 338 decedents, median age was 55.0 years (range: 4 days-97 years); approximately one third were older adults. On tornado impact, 46.7% of decedents were in single-family homes, and 26.6% were in mobile homes. The leading cause of death was traumatic injury, including 21.9% with head injuries. Half of the deadly tornadoes were rated EF-4 or EF-5 and were responsible for 89.5% of the deaths. To prevent tornado-related deaths, health messaging should encourage the public (especially older adults and residents of mobile/manufactured homes) to pre-identify an accessible safe room, prepare the room with personal protection items (e.g., blankets and helmets), and monitor local weather.

Risk of tornado-related death and injury in Oklahoma, May 3, 1999.

PubMed

Daley, W Randolph; Brown, Sheryll; Archer, Pam; Kruger, Elizabeth; Jordan, Fred; Batts, Dahna; Mallonee, Sue

2005-06-15

On May 3, 1999, powerful tornadoes, including a category F5 tornado, swept through Oklahoma. The authors examined all tornado-related deaths, hospital admissions, and emergency department visits to identify important risk factors. Data on deaths and injuries directly related to the tornadoes and information obtained from a survey of residents in the damage path of the F5 tornado were used in a case-control analysis. The direct force of the tornadoes caused 40 deaths, 133 hospital admissions, and 265 emergency department outpatient visits. The risk of death from the F5 tornado was greater for persons who were in mobile homes (odds ratio (OR) = 35.3, 95% confidence interval (CI): 7.8, 175.6) or outdoors (OR = 141.2, 95% CI: 15.9, 6,379.8) when the tornado struck than for those in permanently anchored houses. Risk of severe injury was also greater for persons in mobile homes (OR = 11.8, 95% CI: 3.4, 51.7) or outdoors (OR = 34.3, 95% CI: 4.4, 1,526.2). However, the risk of death (OR = 0.0, 95% CI: 0.0, 9.9), severe injury (OR = 0.0, 95% CI: 0.0, 2.0), or minor injury (OR = 0.8, 95% CI: 0.1, 3.1) was not greater among persons in motor vehicles than among those in houses. The risk of death (OR = 0.6, 95% CI: 0.1, 1.7), severe injury (OR = 0.2, 95% CI: 0.1, 0.6), or minor injury (OR = 0.3, 95% CI: 0.2, 0.7) was lower among those fleeing their homes in motor vehicles than among those remaining. Recommendations involving the relative safety of motor vehicles during a tornado should be evaluated using experience from recent tornado events.

Pre-Post Tornado Effects on Aggressive Children’s Psychological and Behavioral Adjustment Through One-Year Postdisaster

PubMed Central

Lochman, John E.; Vernberg, Eric; Powell, Nicole P.; Boxmeyer, Caroline L.; Jarrett, Matthew; McDonald, Kristina; Qu, Lixin; Hendrickson, Michelle; Kassing, Francesca

2017-01-01

Objective Using a risk-resilience framework, this study examined how varying levels of exposure to a natural disaster (EF-4 tornado) and children’s characteristics (sex; anxiety) influenced the behavioral and psychological adjustment of children who shared a common risk factor predisaster (elevated aggression) prior to exposure through one-year postdisaster. Method Participants included 360 children in 4th–6th grades (65% male; 78% African American) and their parents from predominantly low-income households who were already participating in a longitudinal study of indicated prevention effects for externalizing outcomes when the tornado occurred in 2011. Fourth-grade children who were screened for overt aggressive behavior were recruited in three annual cohorts (120 per year, beginning in 2009). Parent-rated aggression and internalizing problems were assessed prior to the tornado (Wave 1), within a half-year after the tornado (Wave 2), and at a one-year follow-up (Wave 3). Children and parents rated their exposure to aspects of tornado-related traumatic experiences at Wave 3. Results Children displayed less reduction on aggression and internalizing problems if the children had experienced distress after the tornado or fears for their life, in combination with their pre-tornado level of anxiety. Higher levels of children’s and parents’ exposure to the tornado interacted with children’s lower baseline child anxiety to predict less reduction in aggression and internalizing problems one year after the tornado. Conclusion Higher levels of disaster exposure negatively affected at-risk children’s level of improvement in aggression and internalizing problems, when life threat (parent- and child-reported) and child-reported distress after the tornado were moderated by baseline anxiety. PMID:27841691

Dual-Polarimetric Radar-Based Tornado Debris Paths Associated with EF-4 and EF-5 Tornadoes over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Christopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Darden, Christopher B.

2011-01-01

An historic tornado and severe weather outbreak devastated much of the southeastern United States between 25 and 28 April 2011. On 27 April 2011, northern Alabama was particularly hard hit by a large number of tornadoes, including several that reached EF-4 and EF-5 on the Enhanced Fujita damage scale. In northern Alabama alone, there were approximately 100 fatalities and hundreds of more people who were injured or lost their homes during the havoc caused by these violent tornadic storms. Two long-track and violent (EF-4 and EF-5) tornadoes occurred within range of the University of Alabama in Huntsville (UAHuntsville) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). A unique capability of dual-polarimetric radar is the near-real time identification of lofted debris associated with ongoing tornadoes on the ground. The focus of this paper is to analyze the dual-polarimetric radar-inferred tornado debris signatures and identify the associated debris paths of the long-track EF-4 and EF-5 tornadoes near ARMOR. The relative locations of the debris and damage paths for each tornado will be ascertained by careful comparison of the ARMOR analysis with NASA MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite imagery of the tornado damage scenes and the National Weather Service tornado damage surveys. With the ongoing upgrade of the WSR-88D (Weather Surveillance Radar - 1988 Doppler) operational network to dual-polarimetry and a similar process having already taken place or ongoing for many private sector radars, dual-polarimetric radar signatures of tornado debris promise the potential to assist in the situational awareness of government and private sector forecasters and emergency managers during tornadic events. As such, a companion abstract (Schultz et al.) also submitted to this conference explores "The use of dual-polarimetric tornadic debris signatures in an operational setting."

Dual-Polarimetric Radar-Based Tornado Debris Paths Associated with EF-4 and EF-5 Tornadoes over Northern Alabama During the Historic Outbreak of 27 April 2011

NASA Technical Reports Server (NTRS)

Carey, Lawrence D.; Schultz, Chrstopher J.; Schultz, Elise V.; Petersen, Walter A.; Gatlin, Patrick N.; Knupp, Kevin R.; Molthan, Andrew L.; Jedlovec, Gary J.; Darden, Christopher B.

2012-01-01

An historic tornado and severe weather outbreak devastated much of the southeastern United States between 25 and 28 April 2011. On 27 April 2011, northern Alabama was particularly hard hit by a large number of tornadoes, including several that reached EF-4 and EF-5 on the Enhanced Fujita damage scale. In northern Alabama alone, there were approximately 100 fatalities and hundreds of more people who were injured or lost their homes during the havoc caused by these violent tornadic storms. Two long-track and violent (EF-4 and EF-5) tornadoes occurred within range of the University of Alabama in Huntsville (UAHuntsville) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). A unique capability of dual-polarimetric radar is the near-real time identification of lofted debris associated with ongoing tornadoes on the ground. The focus of this paper is to analyze the dual-polarimetric radar-inferred tornado debris signatures and identify the associated debris paths of the long-track EF-4 and EF-5 tornadoes near ARMOR. The relative locations of the debris and damage paths for each tornado will be ascertained by careful comparison of the ARMOR analysis with NASA MODIS (Moderate Resolution Imaging Spectroradiometer) and ASTER (Advanced Spaceborne Thermal Emission and Reflection Radiometer) satellite imagery of the tornado damage scenes and the National Weather Service tornado damage surveys. With the ongoing upgrade of the WSR-88D (Weather Surveillance Radar 1988 Doppler) operational network to dual-polarimetry and a similar process having already taken place or ongoing for many private sector radars, dual-polarimetric radar signatures of tornado debris promise the potential to assist in the situational awareness of government and private sector forecasters and emergency managers during tornadic events. As such, a companion abstract (Schultz et al.) also submitted to this conference explores The use of dual-polarimetric tornadic debris signatures in an operational setting.

Tornado outbreaks associated with landfalling hurricanes in the North Atlantic Basin: 1954 2004

NASA Astrophysics Data System (ADS)

Verbout, S. M.; Schultz, D. M.; Leslie, L. M.; Brooks, H. E.; Karoly, D. J.; Elmore, K. L.

2007-08-01

Tornadoes are a notable potential hazard associated with landfalling hurricanes. The purpose of this paper is to discriminate hurricanes that produce numerous tornadoes (tornado outbreaks) from those that do not (nonoutbreaks). The data consists of all hurricane landfalls that affected the United States from the North Atlantic basin from 1954 to 2004 and the United States tornado record over the same period. Because of the more than twofold increase in the number of reported tornadoes over these 51 years, a simple least-squares linear regression (“the expected number of tornadoes”) was fit to the annual number of tornado reports to represent a baseline for comparison. The hurricanes were sorted into three categories. The first category, outbreak hurricanes, was determined by hurricanes associated with the number of tornado reports exceeding a threshold of 1.5% of the annual expected number of tornadoes and at least 8 F1 and greater tornadoes during the time of landfall (from outer rainbands reaching shore to dissipation of the system). Eighteen hurricane landfalls were classified as outbreak hurricanes. Second, 37 hurricanes having less than 0.5% of the annual expected number of tornadoes were classified as nonoutbreak landfalls. Finally, 28 hurricanes that were neither outbreak nor nonoutbreak hurricanes were classified as midclass hurricane landfalls. Stronger hurricanes are more likely to produce tornado outbreaks than weaker hurricanes. While 78% of outbreak hurricanes were category 2 or greater at landfall, only 32% of nonoutbreak hurricanes were category 2 or greater at landfall. Hurricanes that made landfall along the southern coast of the United States and recurved northeastward were more likely to produce tornadoes than those that made landfall along the east coast or those that made landfall along the southern coast but did not recurve. Recurvature was associated with a 500-hPa trough in the jet stream, which also contributed to increased deep-layer shear through the hurricane, favoring mesocyclogenesis, and increased the low-level shear, favoring tornadogenesis. The origin of the hurricane, date of landfall, and El Niño-Southern Oscillation phase do not appear to be factors in outbreak hurricane creation. The results of this study help clarify inconsistencies in the previous literature regarding tornado occurrences in landfalling hurricanes.

Statistical Examination of Tornado Report and Warning Near-Storm Environments

NASA Astrophysics Data System (ADS)

Anderson-Frey, Alexandra K.

This study makes use of a 13-year dataset of 14,814 tornado events and 44,961 tornado warnings in the continental United States, along with near-storm environmental data associated with each of those tornado events and warnings, to build a methodology that can be used to create nuanced climatologies of near-storm environmental data. Two key parameter spaces are identified as being particularly useful in this endeavor: mixed-layer convective available potential energy (MLCAPE) versus 0-6-km vector shear magnitude (SHR6) and mixed-layer lifting condensation level (MLLCL) versus 0-1-km storm-relative helicity (SRH1). In addition, the Significant Tornado Parameter (STP) is identified as a useful composite parameter that can highlight near-storm environments that are particularly favorable for the development of significant tornadoes. Two particular statistical methods for the analysis and characterization of near-storm environments are described and applied: Kernel Density Estimation (KDE), which is applied to bulk (proximity soundinglike) parameter values associated with each event or warning, and Self-Organizing Maps (SOMs), which are applied to fully two-dimensional plots of STP in an area surrounding each event or warning. The KDE approach characterizes and identifies differences in the environments of tornadoes forming in quasi-linear convective systems versus those forming in right-moving supercells; specific environmental traits are also identified for different geographical regions, seasons, and times of day. Tornado warning performance is found to be best in environments with particularly large values of MLCAPE and SHR6. The early evening transition (EET) period is of particular interest: MLCAPE and MLLCL heights are in the process of falling, and SHR6 and SRH1 are in the process of increasing. Accordingly, tornadoes rated 2 or greater on the enhanced Fujita scale (EF2+) are also most common during the EET, probability of detection (POD) is relatively high, and false-alarm ratio (FAR) is relatively low. Overall, when comparing the distribution of environments for events versus those for warnings, there is no "smoking gun" indicating a systematic problem with forecasting that explains the high overall false-alarm ratio, which instead seems to stem from the inability to know which storms in a given environment will be tornadic. The SOM approach establishes nine statistically distinct clusters of spatial distributions of STP values in the 480 km x 480 km region surrounding each tornado event or warning. For tornado events, distinct patterns are associated more with particular times of day, geographical locations, and times of year, and the use of two-dimensional data rather than point proximity sounding information means that these patterns can be identified and characterized with still more detail; for instance, the archetypal springtime dryline environment in the Great Plains emerges readily from the data. Although high values of STP tend to be associated with relatively high POD and relatively low FAR, the majority of tornado events occur within a pattern of low STP, with relatively high FAR and low POD. The two-dimensional plots produced by the SOM approach provide an intuitive way to create distinct climatologies of tornadic near-storm environments. Having established a methodology through the use of KDE and SOM, this research then examines the topic of tornado outbreaks [defined as ten or more (E)F1+ tornadoes that occur with no more than 6 h or 2,000 km between subsequent tornadoes]. Outbreak tornadoes in a given geographical region have greater SRH1 and SHR6 than isolated tornadoes in the same region, and also have considerably higher POD than isolated tornadoes. When SOMs are created for all (E)F1+ tornadoes, the percentage of outbreak tornadoes in a given node is found to depend more strongly on the magnitude of the STP value surrounding the tornado than its orientation. For the SOM of outbreak tornadoes, outbreaks occurring in environments with higher magnitudes of STP will generally also have the highest casualty rates, regardless of the specific two-dimensional pattern of STP. Two specific tornado outbreaks are then examined through this methodology, which allows the events to be placed into their climatological context with more nuance than typical proximity sounding-based approaches would allow.

Schools in Kansas with Tornado Protection. Shawnee Mission Public Schools--District No. 512.

ERIC Educational Resources Information Center

Ward, Delbert B.

Kansas and nearby Missouri are among the half-dozen states in America having the greatest frequency of tornadoes of any region in the world. This booklet describes a districtwide approach of designing and constructing tornado-resistant shelters as integrated parts of the school facilities. The design criteria for tornado protection also resulted…

After the Storm: Enduring Differences in Mother-Child Recollections of Traumatic and Non-Traumatic Events.

ERIC Educational Resources Information Center

Ackil, Jennifer K.; Van Abbema, Dana L.; Bauer, Patricia J.

2003-01-01

Compared collective reminiscences of mothers and their 3- to 11-year-olds about a tornado and two nontraumatic events (one proceeding and one following the tornado) 4 months post-tornado and again 6 months later. Found that conversations about both traumatic and nontraumatic events varied with age. Children's tornado recollections were…

Wind/tornado design criteria, development to achieve required probabilistic performance goals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, D.S.

1991-06-01

This paper describes the strategy for developing new design criteria for a critical facility to withstand loading induced by the wind/tornado hazard. The proposed design requirements for resisting wind/tornado loads are based on probabilistic performance goals. The proposed design criteria were prepared by a Working Group consisting of six experts in wind/tornado engineering and meteorology. Utilizing their best technical knowledge and judgment in the wind/tornado field, they met and discussed the methodologies and reviewed available data. A review of the available wind/tornado hazard model for the site, structural response evaluation methods, and conservative acceptance criteria lead to proposed design criteriamore » that has a high probability of achieving the required performance goals.« less

Seismic detection of tornadoes

USGS Publications Warehouse

Tatom, F. B.

1993-01-01

Tornadoes represent the most violent of all forms of atmospheric storms, each year resulting in hundreds of millions of dollars in property damage and approximately one hundred fatalities. In recent years, considerable success has been achieved in detecting tornadic storms by means of Doppler radar. However, radar systems cannot determine when a tornado is actually in contact with the ground, expect possibly at extremely close range. At the present time, human observation is the only truly reliable way of knowing that a tornado is actually on the ground. However, considerable evidence exists indicating that a tornado in contact with the ground produces a significant seismic signal. If such signals are generated, the seismic detection and warning of an imminent tornado can become a distinct possibility. 

Wind/tornado design criteria, development to achieve required probabilistic performance goals

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, D.S.

This paper describes the strategy for developing new design criteria for a critical facility to withstand loading induced by the wind/tornado hazard. The proposed design requirements for resisting wind/tornado loads are based on probabilistic performance goals. The proposed design criteria were prepared by a Working Group consisting of six experts in wind/tornado engineering and meteorology. Utilizing their best technical knowledge and judgment in the wind/tornado field, they met and discussed the methodologies and reviewed available data. A review of the available wind/tornado hazard model for the site, structural response evaluation methods, and conservative acceptance criteria lead to proposed design criteriamore » that has a high probability of achieving the required performance goals.« less

Adolescent Substance Use Following a Deadly U.S. Tornado Outbreak: A Population-Based Study of 2,000 Families.

PubMed

Danielson, Carla Kmett; Sumner, Jennifer A; Adams, Zachary W; McCauley, Jenna L; Carpenter, Matthew; Amstadter, Ananda B; Ruggiero, Kenneth J

2017-01-01

Despite conceptual links between disaster exposure and substance use, few studies have examined prevalence and risk factors for adolescent substance use and abuse in large, population-based samples affected by a recent natural disaster. We addressed this gap using a novel address-based sampling methodology to interview adolescents and parents who were affected by the 4th deadliest tornado outbreak in U.S. Postdisaster interviews were conducted with 2,000 adolescent-parent dyads living within a 5-mile radius of the spring 2011 U.S. tornadoes. In addition to descriptive analyses to estimate prevalence, hierarchical linear and logistic regression analyses were used to examine a range of protective and risk factors for substance use and abuse. Approximately 3% reported substance abuse since the tornado. Greater number of prior traumatic events and older age emerged as consistent risk factors across tobacco and alcohol use and substance abuse since the tornado. Tornado incident characteristics, namely, greater loss of services and resources after the tornado and posttraumatic stress disorder since the tornado, were associated with greater alcohol consumption. Service loss increased risk for binge drinking, whereas, for substance abuse, posttraumatic stress disorder increased risk and parent presence during the tornado decreased risk. Greater family tornado exposure was associated with a greater number of cigarettes smoked in female but not male teen participants. Both trauma and non-trauma-related factors are relevant to postdisaster substance abuse among adolescents. Future research should examine the role of broader ecological systems in heightening or curtailing substance use risk for adolescents following disaster exposure.

Adolescent Substance Use Following A Deadly U.S. Tornado Outbreak: A Population-Based Study of 2,000 Families

PubMed Central

Danielson, Carla Kmett; Sumner, Jennifer A.; Adams, Zachary W.; McCauley, Jenna L.; Carpenter, Matthew; Amstadter, Ananda B.; Ruggiero, Kenneth J.

2015-01-01

Objective Despite conceptual links between disaster exposure and substance use, few studies have examined prevalence and risk factors for adolescent substance use and abuse in large, population-based samples affected by a recent natural disaster. We addressed this gap using a novel address-based sampling methodology to interview adolescents and parents who were affected by the fourth deadliest tornado outbreak in U.S. history. Method Post-disaster interviews were conducted with 2,000 adolescent-parent dyads living within a 5-mile radius of the Spring 2011 U.S. tornadoes. In addition to descriptive analyses to estimate prevalence, hierarchical linear and logistic regression analyses were used to examine a range of protective and risk factors for substance use and abuse. Results Approximately 3% reported substance abuse since the tornado. Greater number of prior traumatic events and older age emerged as consistent risk factors across tobacco and alcohol use and substance abuse since the tornado. Tornado incident characteristics, namely greater loss of services and resources after the tornado and PTSD since the tornado, were associated with greater alcohol consumption. Service loss increased risk for binge drinking, whereas, for substance abuse, PTSD increased risk and parent presence during the tornado decreased risk. Greater family tornado exposure was associated with a greater number of cigarettes smoked in female but not male teen participants. Conclusions Both trauma and non-trauma-related factors are relevant to post-disaster substance abuse among adolescents. Future research should examine the role of broader ecological systems in heightening or curtailing substance use risk for adolescents following disaster exposure. PMID:26605673

Assessment of the Public Health Risks and Impact of a Tornado in Funing, China, 23 June 2016: A Retrospective Analysis.

PubMed

Wang, Kaiwen; Zhong, Shuang; Wang, Xiaoye; Wang, Zhe; Yang, Lianping; Wang, Qiong; Wang, Suhan; Sheng, Rongrong; Ma, Rui; Lin, Shao; Liu, Wenyu; Zu, Rongqiang; Huang, Cunrui

2017-10-10

(1) Background: Tornadoes are one of the deadliest disasters but their health impacts in China are poorly investigated. This study aimed to assess the public health risks and impact of an EF-4 tornado outbreak in Funing, China; (2) Methods: A retrospective analysis on the characteristics of tornado-related deaths and injuries was conducted based on the database from the Funing's Center for Disease Control and Prevention (CDC) and Funing People's Hospital. A change-point time-series analysis of weekly incidence for the period January 2010 to September 2016 was used to identify sensitive infectious diseases to the tornado; (3) Results: The 75 to 84 years old group was at the highest risk of both death (RR = 82.16; 95% CIs = 19.66, 343.33) and injury (RR = 31.80; 95% CI = 17.26, 58.61), and females were at 53% higher risk of death than males (RR = 1.53; 95% CIs = 1.02, 2.29). Of the 337 injuries, 274 injuries (81%) were minor. Most deaths occurred indoors (87%) and the head (74%) was the most frequent site of trauma during the tornado. Five diseases showed downward change-points; (4) Conclusions: The experience of the Funing tornado underscores the relative danger of being indoors during a tornado and is successful in avoiding epidemics post-tornado. Current international safety guidelines need modification when generalized to China.

Tornadoes

MedlinePlus

Tornadoes are nature's most violent storms. They are rotating, funnel-shaped clouds that extend from a thunderstorm ... over a mile wide and 50 miles long. Tornadoes can also accompany tropical storms and hurricanes as ...

Residential tornado safe room from commodity wood products – design and development

Treesearch

Robert H. Falk; James J. Bridwell

2018-01-01

In the United States, tornadoes cause significant damage and result in many injuries and deaths. Although the development and use of tornado safe rooms have helped decrease the human toll associated with these events, the cost of these structures is often too high for many that could benefit from their use. The development of a nonproprietary residential tornado safe...

Physical Patterns Associated with 27 April 2011 Tornado Outbreak

NASA Astrophysics Data System (ADS)

Ramos, Fernanda; Salem, Thomas

2012-02-01

The National Weather Service office in Memphis, Tennessee has aimed their efforts to improve severe tornado forecasting. Everything is not known about tornadogenesis, but one thing is: tornadoes tend to form within supercell thunderstorms. Hence, 27 April 2011 and 25 May 2011 were days when a Tornado Outbreak was expected to arise. Although 22 tornadoes struck the region on 27 April 2011, only 1 impacted the area on 25 May 2011. In order to understand both events, comparisons of their physical features were made. These parameters were studied using the Weather Event Simulator system and the NOAA/NWS Storm Prediction database. This research concentrated on the Surface Frontal Analysis, NAM40 700mb Dew-Points, NAM80 250mb Wind Speed and NAM20 500mb Vorticity images as well as 0-6 km Shear, MUCAPE and VGP mesoscale patterns. As result of this research a Dry-Line ahead of a Cold Front, Dew-points 5C and higher, and high Vorticity values^ were synoptic patterns that influenced to the formation of supercell tornadoes. Finally, MUCAPE and VGP favored the possibility of tornadoes occurrence on 25 May 2011, but shear was the factor that made 27 April 2011 a day for a Tornado Outbreak weather event.

Intense tornadoes in Poland in the years 2000-2012 and their synoptic characteristics

NASA Astrophysics Data System (ADS)

Cwik, Paulina

2015-04-01

Tornadoes, or high speed rotating columns of air, are some of the most extreme natural processes occurring on Earth. Currently the trend towards more frequent and more severe occurrence of tornadoes appear also in Poland. So far, tornadoes in Poland resulted in very serious damage to infrastructure and led to injury or death many of the people. Forecast of tornados is not a easy task, especially when the phenomenon is local. Must be based on a comprehensive analysis of mesoscale numerical models, atmospheric soundings and radar data. Unfortunately, there are a number of limitations.One of it, is that the mesoscale weather models often do not capture local events, so forecast of the tornados in real time and place can not occur well in advance. The phenomenon of tornadoes must be better understood and become the object of a comprehensive analysis, so that the resulting information can be used both for research purposes as well as educational.

Two Solar Tornadoes Observed with the Interface Region Imaging Spectrograph

NASA Astrophysics Data System (ADS)

Yang, Zihao; Tian, Hui; Peter, Hardi; Su, Yang; Samanta, Tanmoy; Zhang, Jingwen; Chen, Yajie

2018-01-01

The barbs or legs of some prominences show an apparent motion of rotation, which are often termed solar tornadoes. It is under debate whether the apparent motion is a real rotating motion, or caused by oscillations or counter-streaming flows. We present analysis results from spectroscopic observations of two tornadoes by the Interface Region Imaging Spectrograph. Each tornado was observed for more than 2.5 hr. Doppler velocities are derived through a single Gaussian fit to the Mg II k 2796 Å and Si IV 1393 Å line profiles. We find coherent and stable redshifts and blueshifts adjacent to each other across the tornado axes, which appears to favor the interpretation of these tornadoes as rotating cool plasmas with temperatures of 104 K–105 K. This interpretation is further supported by simultaneous observations of the Atmospheric Imaging Assembly on board the Solar Dynamics Observatory, which reveal periodic motions of dark structures in the tornadoes. Our results demonstrate that spectroscopic observations can provide key information to disentangle different physical processes in solar prominences.

Casualty Risk From Tornadoes in the United States is Highest in Urbanized Areas Across the Mid South

NASA Astrophysics Data System (ADS)

Fricker, T.; Elsner, J.

2017-12-01

Risk factors for tornado casualties are well known. Less understood is how and to what degree these determinants, after controlling for strength and urban density, vary spatially and temporally. Here we fit models to casualty counts from all casualty-producing tornadoes since 1995 in order to quantify the interactions between urbanization and energy on casualty rates. Results from the models show that the more urbanized areas of the Mid South are substantively and significantly more vulnerable to casualties from tornadoes than elsewhere in the country. Casualty rates are significantly higher on the weekend for tornadoes in this region. Night and day casualty rates are similar regardless of where they occur. Higher vulnerability to casualties from tornadoes occurring in more urbanized areas correspond significantly with greater percentages of elderly people. Many of the micro cities in the Mid South are threatened by tornadoes annually and this threat might potentially be exacerbated by climate change.

Tornado-associated fatalities--Arkansas, 1997.

PubMed

1997-05-16

On March 1, 1997, approximately nine tornadoes originating from two separate thunderstorms swept across Arkansas, from Hempstead County in the southwest to Clay County in the northeast (approximately 260 miles). The tornadoes caused 26 deaths and an estimated $115 million in property damage, reflecting damage to residences, nonresidential buildings, bridges, and roads and agriculture and timber losses. The strongest tornadoes touched down southwest of Little Rock in Clark, Saline, and Pulaski counties; the estimated widths of the tornado paths ranged from 1/2 to 1 mile, and wind speeds were > 200 miles per hour (National Weather Service [NWS], unpublished data, 1997). This report summarizes circumstances of the tornado-associated fatalities from information collected by the American Red Cross (ARC); 14 of the 26 fatalities occurred among persons who were in mobile homes.

Remote sensing of tornadic storms from geosynchronous satellite infrared digital data

NASA Technical Reports Server (NTRS)

Hung, R. J.; Smith, R. E.

1982-01-01

Two cases of GOES digital infrared data were analyzed during the three-hour period immediately prior to the tornado touchdown times. Clouds associated with tornadoes were compared to those without tornadoes using a combination of satellite infrared and rawinsonde data. On the basis of this limited data sample, it appears as if the altitude to which the overshooting cloud top penetrated above the tropopause is the factor which determines whether or not a tornado is formed. In these cases, the overshooting cloud top collapsed about 15 to 30 min before the tornado touchdown.

Cloud-to-Ground Lightning Characteristics of a Major Tropical Cyclone Tornado Outbreak

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Buechler, Dennis; Goodman, Steven J.

1999-01-01

It is well known that most tropical cyclones (TCs) that make landfall along the Gulf coast of the United States spawn at least a few tornadoes. Although most landfalling TCs generate fewer than a dozen such tornadoes, a small proportion produce large swarm outbreaks, with as many as 25 or more tornadoes. Usually, these major outbreaks occur in large, intense hurricane-strength TCs, but on 15-17 August 1994 Tropical Storm Beryl spun off 37 tornadoes along its path from the Florida panhandle through the mid-Atlantic states. Some 32 of these tornadoes occurred on 16 August 1994 from eastern Georgia to southern Virginia, with most of these taking place in South Carolina. Beryl's 37 tornadoes moved it into what was at that time fifth place historically in terms of TC tornado productivity. The Beryl outbreak is especially noteworthy in that at least three of the tornadoes achieved peak intensity of F3 on the Fujita damage intensity scale. Although no fatalities resulted from the Beryl outbreak, at least 50 persons suffered injuries, and property damages totalled more than $50 million . The Beryl outbreak is a good example of a TC whose greatest danger to the public is its post-landfall severe weather. In this respect, and in the character of its swarm outbreak of tornadoes, it resembles another large tornado outbreak spawned by a relatively weak TC, Hurricane Danny of 1985). In the Danny outbreak, numerous shallow mini-supercell storms were found to have occurred, and it was noted that, because of the storms' relatively shallow depth, cloud-to-ground (CG) lightning was negligible. Better observations of future TC tornado outbreaks, especially with modern surveillance tools such as Doppler radars and the National Lightning Detection Network (NLDN), were recommended. Although the Beryl tornado outbreak is not the first set of TC-spawned tornado storms to be observed with the NLDN, it is one of the largest and likely the most intense such outbreak. The purpose of this paper is to document the NLDN-derived CG lightning characteristics of Beryl's tornadic storms, and to see how they compare with observations of CG lightning activity in other types of severe storms. In particular, we attempt to quantify the CG flash rates of TC tornadic cells, and to discover if there are any characteristics of their CG activity that may be useful to operational forecasters seeking to distinguish which cells are most likely to produce severe weather.

Assessing anthropogenic and natural disturbances: forest response to similarly aged clearcut and tornado disturbances in an east Tennessee oak-hickory forest

Treesearch

Jonathan C. McGrath; Wayne K. Clatterbuck

2013-01-01

In February of 1993, an F3 tornado caused a large-scale disturbance in an east Tennessee oak-hickory (Quercus spp.-Carya spp.) forest. Vegetation response to anthropogenic and natural disturbances was compared by examining two tornado-disturbed areas and five adjacent 1-acre silvicultural clearcut areas unaffected by the tornado...

Residential Tornado Safe Rooms from Commodity Wood Products: Wall Development and Impact Testing

Treesearch

Robert H. Falk; James J. Bridwell; John C. Hermanson

2015-01-01

In the United States, tornadoes cause significant damage and result in many injuries and deaths. Although the development and use of tornado safe rooms and shelters have helped reduce the human toll associated with these events, the cost of these structures is often too high for many that could benefit from their use. The development of a residential tornado safe room...

Tornadoes within the Czech Republic: from early medieval chronicles to the "internet society"

NASA Astrophysics Data System (ADS)

Setvák, Martin; Šálek, Milan; Munzar, Jan

This paper addresses the historical documentation of tornadoes and the awareness of tornadic events in the area of the present Czech Republic throughout the last nine centuries. The oldest records of tornado occurrence in the region can be found in chronicles from the first half of the 12th century—the two most interesting of these are presented here in translation from the original Latin texts. Several other cases of possible tornadoes and waterspouts can be found in chronicles from the 12th and 13th centuries. However, from the descriptions of the events, it is not always clear if the phenomenon was a tornado, waterspout, dust swirl, or if it was of a non-tornadic nature. From the 14th to 19th centuries, tornado records are rather scarce for the region. However, this is likely to have a non-meteorological explanation. Gregor Mendel's (1871) essay " Die Windhose vom 13. October 1870" can be considered as a distinctive "breakpoint" in the documentation history of tornadoes in the territory of the present Czech Republic, followed later by the work of Edler von Wahlburg [Das Wetter 28 (1911) 135] and Wegener [Wind-und-Wasserhosen in Europa. F. Vieweg & Sohn, Braunschweig, 1917]. During the "socialist" period, the term " tornado" was seldom used and they were poorly understood, producing a view that "tornadoes do not occur in Central Europe". The situation began to change with the works of Munzar [Tromby (tonáda) na území Èeské republiky v letech 1119-1993. Zborník Dejin Fyziky, vol. XI. Voj. Akadémia SNP, Liptovský Mikuláš, pp. 69-72, 1993 (in Czech)] and Šálek [Meteorol. Zpr. 47 (1994) 172], and new records showed that about one tornado per year occurred between 1994 and 1999. Finally, between 2000 and 2002, the number of documented tornadoes in the Czech Republic was five to eight cases per year.

Multiple cyclic tornado production modes in the 5 May 2007 Greensburg, Kansas supercell storm

NASA Astrophysics Data System (ADS)

Tanamachi, Robin Lynn

Long-track, violent tornadoes are rare events, but are responsible for a disproportionate majority of tornado fatalities, injuries, and property damage. It has been observed that such tornadoes are often generated as part of a series produced by one supercell, and preceded by one or more smaller tornadoes. At some point, a transition in the tornado production mode occurs, from short-track, cyclic tornado production (mode I), to long-track, single (plus satellite) tornado production (mode II). This transition has been documented only a few times at close range by Doppler weather radars. A cyclic, tornadic supercell ("the Greensburg storm") generated at least 22 tornadoes in southwest Kansas on 5 May 2007. One of these was the first documented EF-5 tornado ("the Greensburg tornado"), which destroyed 95% of the buildings in Greensburg, Kansas and caused 11 fatalities. The University of Massachusetts X-band, polarimetric, mobile Doppler radar (UMass X-Pol), which was operating in the area as part of a severe storms research project, collected data in the Greensburg storm for over an hour, including its transition from tornado production mode I to mode II. The first 10 tornadoes produced by the Greensburg storm can be seen in this UMass X-Pol data set. In this study, the UMass X-Pol data (as well as contemporaneous data from the WSR-88D at Dodge City, Kansas, or KDDC) are analyzed with the aim of diagnosing whether this transition occurred as a result of changes in the environmental wind profile, interaction of tornadoes with the storm's cold pool, or a combination of the two. These efforts met with limited success, largely because of the relative scarcity of observations of low-level flow in the inflow sector of the Greensburg storm. However, in the process, features of the Greensburg storm related to tornado production (such as vortices, updrafts, and polarimetric signatures) are documented, and relationships among them before, during, and after this transition are diagnosed. In particular, it is found that: (1) The horizontal motions of the earlier tornadoes (mode I) tracked to the left with respect to the updraft motion, while the motion of the Greensburg tornado and its satellites (mode II) more closely matched that of the updraft. (2) The vortex signatures in the UMass X-Pol data matched with the surveyed damage tracks. In addition, several non-tornadic circulations were documented. (4) A forward surge and retreat of a RFGF was documented a few minutes before the development of the Greensburg tornado. (4) At least two cyclonic-anticyclonic pairs of satellite tornadoes (of the Greensburg tornado) occurred, possibly indicating the upward arching of low-level horizontal vortex lines over bulges in the RFGF. (5) Weak-echo holes are documented in several tornadoes, and found to be consistently collocated with corresponding vortex signatures in azimuth but biased slightly far from the radar in range. (6) A polarimetric tornadic debris signature is found near the surface in the mature Greensburg tornado. In addition, a ZDR arc is documented whose presence corroborates increasing low-level vertical wind shear in the inflow sector. Other polarimetric supercell features are consistent with those found in previous studies. In an attempt to retrieve in-storm variables not observed by radar, KDDC and UMass X-Pol radar data were assimilated into a numerical weather prediction model using the ensemble Kalman filter (EnKF) technique. Two sets of experiments were performed, one in which UMass X-Pol data were either included or withheld from assimilation with KDDC data, and another in which the 0 -- 3 km AGL initial environmental wind profile was modified to include a low-level jet, or not. Assimilation of UMass X-Pol data results in more pronounced changes to the analyses than the addition of a low-level jet, although both changes result in nearsurface vortices that are stronger, deeper, and longer-lived than in experiments without. When UMass X-Pol data are assimilated, vortices appear in the analyses that correspond to mode I tornadoes, and the southward-spreading, surface cold pool from the Greensburg storm (which likely results from the use of a relatively simple microphysical parameterization scheme) deflects around the assimilated observations of southerly flow at the UMass X-Pol deployment site. Neither of these features appear when UMass X-Pol data are withheld. I close by discussing the implications of these results for future avenues of research involving analysis and assimilation of data from mobile Doppler radars, including storm-scale prediction.

National Weather Service: Watch, Warning, Advisory Display

MedlinePlus

... Education & Outreach About the SPC SPC FAQ About Tornadoes About Derechos Video Lecture Series WCM Page Enh. ... Convective/Tropical Weather Flooding Winter Weather Non-Precipitation Tornado Watch Tornado Warning* Severe Thunderstorm Watch Severe Thunderstorm ...

Risk factors for death in the 27 March 1994 Georgia and Alabama tornadoes.

PubMed

Schmidlin, T W; King, P S

1995-06-01

Field surveys were made one week after tornadoes killed 40 persons and injured over 300 in rural regions of Alabama and Georgia, USA, on 27 March 1994. Surveys were completed for samples of 20 persons who were killed and 31 persons who were in the paths of the tornadoes but survived to determine whether there were differences in personal characteristics, behavior or location between the two groups. Persons who died were significantly older than persons who survived, more likely to be in mobile homes or in rooms above ground with windows, less likely to be watching television before the tornado, and were aware of the approaching tornado for less time than survivors. There was no difference in gender, race, marital status, education, disability or previous experience with tornadoes between those who died and survivors.

An experimental investigation of flow around a vehicle passing through a tornado

NASA Astrophysics Data System (ADS)

Suzuki, Masahiro; Obara, Kouhei; Okura, Nobuyuki

2016-03-01

Flow around a vehicle running through a tornado was investigated experimentally. A tornado simulator was developed to generate a tornado-like swirl flow. PIV study confirmed that the simulator generates two-celled vortices which are observed in the natural tornadoes. A moving test rig was developed to run a 1/40 scaled train-shaped model vehicle under the tornado simulator. The car contained pressure sensors, a data logger with an AD converter to measure unsteady surface pressures during its run through the swirling flow. Aerodynamic forces acting on the vehicle were estimated from the pressure data. The results show that the aerodynamic forces change its magnitude and direction depending on the position of the car in the swirling flow. The asymmetry of the forces about the vortex centre suggests the vehicle itself may deform the flow field.

Implications of Prenatal Exposure to the Spring 2011 Alabama and Missouri Tornadoes on Birth Outcomes.

PubMed

Christopher, Kenneth E; Kitsantas, Panagiota; Spooner, Kiara K; Robare, Joseph F; Hanfling, Dan

2018-06-20

Despite emerging evidence of the detrimental effects of natural disasters on maternal and child health, little is known about exposure to tornadoes during the prenatal period and its impact on birth outcomes. We examined the relationship between prenatal exposure to the spring 2011 tornado outbreak in Alabama and Joplin (Missouri) and adverse birth outcomes. We conducted a retrospective, cross-sectional cohort study using the 2010-2012 linked infant births and deaths data set from the National Center for Health Statistics for tornado-affected counties in Alabama (n=126,453) and Missouri (Joplin, n=6,897). Chi-square and logistic regression analyses were performed to estimate associations between prenatal exposure to tornadoes and birth outcomes. Prenatal exposure to the tornado incidents did not influence birth weight outcomes. Women exposed to Alabama tornadoes were less likely to have a preterm birth compared to unexposed mothers (OR: 0.93, 95% CI: 0.91, 0.96). Preterm births among Joplin-tornado exposed mothers were slightly higher (13%) compared with unexposed mothers (11.2%). Exposed mothers from Joplin were also more likely to have a cesarean section compared to their counterparts (OR: 1.14, 95% CI: 1.02, 1.26). We found no association between tornado exposure and adverse birth weight and infant mortality rates. Our findings suggest that prenatal exposure can amplify the odds for a cesarean section. (Disaster Med Public Health Preparedness. 2018;page 1 of 8).

Assessment of the Public Health Risks and Impact of a Tornado in Funing, China, 23 June 2016: A Retrospective Analysis

PubMed Central

Wang, Kaiwen; Zhong, Shuang; Wang, Xiaoye; Wang, Zhe; Yang, Lianping; Wang, Qiong; Wang, Suhan; Sheng, Rongrong; Ma, Rui; Lin, Shao; Liu, Wenyu; Zu, Rongqiang; Huang, Cunrui

2017-01-01

(1) Background: Tornadoes are one of the deadliest disasters but their health impacts in China are poorly investigated. This study aimed to assess the public health risks and impact of an EF-4 tornado outbreak in Funing, China; (2) Methods: A retrospective analysis on the characteristics of tornado-related deaths and injuries was conducted based on the database from the Funing’s Center for Disease Control and Prevention (CDC) and Funing People’s Hospital. A change-point time-series analysis of weekly incidence for the period January 2010 to September 2016 was used to identify sensitive infectious diseases to the tornado; (3) Results: The 75 to 84 years old group was at the highest risk of both death (RR = 82.16; 95% CIs = 19.66, 343.33) and injury (RR = 31.80; 95% CI = 17.26, 58.61), and females were at 53% higher risk of death than males (RR = 1.53; 95% CIs = 1.02, 2.29). Of the 337 injuries, 274 injuries (81%) were minor. Most deaths occurred indoors (87%) and the head (74%) was the most frequent site of trauma during the tornado. Five diseases showed downward change-points; (4) Conclusions: The experience of the Funing tornado underscores the relative danger of being indoors during a tornado and is successful in avoiding epidemics post-tornado. Current international safety guidelines need modification when generalized to China. PMID:28994741

Increased tornado hazard in large metropolitan areas

NASA Astrophysics Data System (ADS)

Cusack, Stephen

2014-11-01

The tornado climate was compared between large metropolitan areas and neighbouring non-metro cities using modern tornado reports in the Storm Prediction Center (SPC) archives. Twenty large metro areas in the higher-risk region of the U.S. were used to boost sample sizes hence robustness of results. Observational biases were minimised by using the most densely populated zips. The analysis found 50% greater tornado frequency and a thicker-tailed severity distribution in metro areas compared to the non-metro cities. These differences are significant at the 1% level. Regarding tornado frequency, the primary question is whether the raised occurrence rates in metro areas are due to observation biases or real differences in tornado climate. Past studies found no relative biases at the population densities used here, whereas there are two potential urban drivers of tornadogenesis. First, the urban heat island raises the storm severity above and downwind of main urban areas, as recorded in precipitation and lightning datasets. Second, the increased surface roughness over metro areas raises low-level shear which in turn has been found to be favourable for tornadogenesis. Modification of convective storms over large metro areas is the more plausible explanation of raised tornado frequency. The drivers of a thicker-tailed tornado severity distribution in metro areas are less certain. Potential causes include: increased debris-loading in metro tornadoes; modification of storms' lower boundary layer by increased surface roughness in metro areas; the reduced density of damage indicators in non-metro cities.

Future Contracting for Availability

DTIC Science & Technology

2016-04-30

including Tornado and Harrier fast jets, and logistics activities related to aerial refueling. These cases outline the benefits achieved on these...platforms—including savings in the billions of pounds. Tornado and Harrier Aircraft Under the Tornado and Harrier programs, the Royal Air Force paid...owned K-707 and KDC-10 to refuel British Royal Air Force (RAF) GR-4A Tornadoes and Canadian Air Force CF-18s during training operations. Over the

Resilient National Security and Emergency Preparedness Communications: Service Metrics

DTIC Science & Technology

2015-10-01

the East Coast of the United States after a tornado . Emergency management services are immediately called into duty to protect, provide, and secure...channel, radios that are vulnerable to congestion during heavy usage. During a tornado emergency prior to the hurricane, in a period of only 10...In terms of Survivability, the probability of a tornado occurring in any given year in this location is P( tornado ) = 0.05. The

Wind pressure testing of tornado safe room components made from wood

Treesearch

Robert Falk; Deepak Shrestha

2016-01-01

To evaluate the ability of a wood tornado safe room to resist wind pressures produced by a tornado, two safe room com-ponents were tested for wind pressure strength. A tornado safe room ceiling panel and door were static-pressure-tested according to ASTM E 330 using a vacuum test system. Re-sults indicate that the panels had load capacities from 2.4 to 3.5 times that...

ASTER Images Aftermath of U.S. Tornado Outbreak

NASA Image and Video Library

2011-05-06

From April 25-28, 2011, one of the largest outbreaks of tornadoes ever recorded ripped across the Southern, Midwestern and Eastern United States. NASA Terra spacecraft shows the scar the tornado left across Birmingham, Alabama.

Tornado-Shaped Curves

ERIC Educational Resources Information Center

Martínez, Sol Sáez; de la Rosa, Félix Martínez; Rojas, Sergio

2017-01-01

In Advanced Calculus, our students wonder if it is possible to graphically represent a tornado by means of a three-dimensional curve. In this paper, we show it is possible by providing the parametric equations of such tornado-shaped curves.

Analytical vacuum force, atmospheric pressure dispute

NASA Astrophysics Data System (ADS)

Yongquan, Han

Typically, the gap gas molecules is 10-9 m, since the center speed of the tornado is over 100 m / sec, it divided by the speed of a tornado, the gap of the gas molecules becomes 10-11m. Equivalent to the gap when there is no tornado that the gas molecules allow radiation to pass through, equivalent to the gap is reduced gas molecules 100 times by a tornado. There is no change in the Earth's radiate, the Earth's radiation is reduced to one percent of the original intensity by the radiation through the tornado periphery into the center of the tornado. According to the APS Division of Nuclear Physics in APS -2013 Fall Meeting - Event - Gravitational radiation theory http://meetings.aps.org/Meeting/DNP13/Session/FB.8, which I published, the gravity will br reduced to the original gravity percentage one. Waterspout by the Earth's gravity to become the original one percent. Cause the external of the tornadoes atmospheric pressure is constant, the height waterspout should support column height atmospheric pressure is 100 times,that height waterspout may reach nearly kilometers.

Population and energy elasticity of tornado casualties

NASA Astrophysics Data System (ADS)

Fricker, Tyler; Elsner, James B.; Jagger, Thomas H.

2017-04-01

Tornadoes are capable of catastrophic destruction and mass casualties, but there are yet no estimates of how sensitive the number of casualties are to changes in the number of people in harm's way or to changes in tornado energy. Here the relationship between tornado casualties (deaths and injuries), population, and energy dissipation is quantified using the economic concept of "elasticity." Records of casualties from individual tornadoes over the period 2007-2015 are fit to a regression model. The coefficient on the population term (population elasticity) indicates that a doubling in population increases the casualty rate by 21% [(17, 24)%, 95% credible interval]. The coefficient on the energy term (energy elasticity) indicates that a doubling in energy dissipation leads to a 33% [(30, 35)%, 95% credible interval] increase in the casualty rate. The difference in elasticity values show that on average, changes in energy dissipation have been relatively more important in explaining tornado casualties than changes in population. Assuming no changes in warning effectiveness or mitigation efforts, these elasticity estimates can be used to project changes in casualties given the known population trends and possible trends in tornado activity.

Central American biomass burning smoke can increase tornado severity in the U.S.

NASA Astrophysics Data System (ADS)

Saide, P. E.; Spak, S. N.; Pierce, R. B.; Otkin, J. A.; Schaack, T. K.; Heidinger, A. K.; Silva, A. M.; Kacenelenbogen, M.; Redemann, J.; Carmichael, G. R.

2015-02-01

Tornadoes in the Southeast and central U.S. are episodically accompanied by smoke from biomass burning in central America. Analysis of the 27 April 2011 historical tornado outbreak shows that adding smoke to an environment already conducive to severe thunderstorm development can increase the likelihood of significant tornado occurrence. Numerical experiments indicate that the presence of smoke during this event leads to optical thickening of shallow clouds while soot within the smoke enhances the capping inversion through radiation absorption. The smoke effects are consistent with measurements of clouds and radiation before and during the outbreak. These effects result in lower cloud bases and stronger low-level wind shear in the warm sector of the extratropical cyclone generating the outbreak, two indicators of higher probability of tornadogenesis and tornado intensity and longevity. These mechanisms may contribute to tornado modulation by aerosols, highlighting the need to consider aerosol feedbacks in numerical severe weather forecasting.

A Bayesian modelling framework for tornado occurrences in North America

NASA Astrophysics Data System (ADS)

Cheng, Vincent Y. S.; Arhonditsis, George B.; Sills, David M. L.; Gough, William A.; Auld, Heather

2015-03-01

Tornadoes represent one of nature’s most hazardous phenomena that have been responsible for significant destruction and devastating fatalities. Here we present a Bayesian modelling approach for elucidating the spatiotemporal patterns of tornado activity in North America. Our analysis shows a significant increase in the Canadian Prairies and the Northern Great Plains during the summer, indicating a clear transition of tornado activity from the United States to Canada. The linkage between monthly-averaged atmospheric variables and likelihood of tornado events is characterized by distinct seasonality; the convective available potential energy is the predominant factor in the summer; vertical wind shear appears to have a strong signature primarily in the winter and secondarily in the summer; and storm relative environmental helicity is most influential in the spring. The present probabilistic mapping can be used to draw inference on the likelihood of tornado occurrence in any location in North America within a selected time period of the year.

A Bayesian modelling framework for tornado occurrences in North America.

PubMed

Cheng, Vincent Y S; Arhonditsis, George B; Sills, David M L; Gough, William A; Auld, Heather

2015-03-25

Tornadoes represent one of nature's most hazardous phenomena that have been responsible for significant destruction and devastating fatalities. Here we present a Bayesian modelling approach for elucidating the spatiotemporal patterns of tornado activity in North America. Our analysis shows a significant increase in the Canadian Prairies and the Northern Great Plains during the summer, indicating a clear transition of tornado activity from the United States to Canada. The linkage between monthly-averaged atmospheric variables and likelihood of tornado events is characterized by distinct seasonality; the convective available potential energy is the predominant factor in the summer; vertical wind shear appears to have a strong signature primarily in the winter and secondarily in the summer; and storm relative environmental helicity is most influential in the spring. The present probabilistic mapping can be used to draw inference on the likelihood of tornado occurrence in any location in North America within a selected time period of the year.

Tornado wind-loading requirements based on risk assessment techniques

DOE Office of Scientific and Technical Information (OSTI.GOV)

Deobald, T.L.; Coles, G.A.; Smith, G.L.

Regulations require that nuclear power plants be protected from tornado winds. If struck by a tornado, a plant must be capable of safely shutting down and removing decay heat. Probabilistic techniques are used to show that risk to the public from the US Department of Energy (DOE) SP-100 reactor is acceptable without tornado hardening parts of the secondary system. Relaxed requirements for design wind loadings will result in significant cost savings. To demonstrate an acceptable level of risk, this document examines tornado-initiated accidents. The two tornado-initiated accidents examined in detail are loss of cooling resulting in core damage and lossmore » of secondary system boundary integrity leading to sodium release. Loss of core cooling is analyzed using fault/event tree models. Loss of secondary system boundary integrity is analyzed by comparing the consequences to acceptance criteria for the release of radioactive material or alkali metal aerosol. 4 refs., 4 figs.« less

A buoyant tornado-probe concept incorporating an inverted lifting device. [and balloon combination

NASA Technical Reports Server (NTRS)

Grant, F. C.

1973-01-01

Addition of an inverted lifting device to a simple balloon probe is shown to make possible low-altitude entry to tornado cores with easier launch conditions than for the simple balloon probe. Balloon-lifter combinations are particularly suitable for penetration of tornadoes with average to strong circulation, but tornadoes of less than average circulation which are inaccessible to simple balloon probes become accessible. The increased launch radius which is needed for access to tornadoes over a wide range of circulation results in entry times of about 3 minutes. For a simple balloon probe the uninflated balloon must be first dropped on, or near, the track of the tornado from a safe distance. The increase in typical launch radius from about 0.75 kilometer to slightly over 1.0 kilometer with a balloon-lifter combination suggests that a direct air launch may be feasible.

Proposed techniques for launching instrumented balloons into tornadoes

NASA Technical Reports Server (NTRS)

Grant, F. C.

1971-01-01

A method is proposed to introduce instrumented balloons into tornadoes by means of the radial pressure gradient, which supplies a buoyancy force driving to the center. Presented are analytical expressions, verified by computer calculations, which show the possibility of introducing instrumented balloons into tornadoes at or below the cloud base. The times required to reach the center are small enough that a large fraction of tornadoes are suitable for the technique. An experimental procedure is outlined in which a research airplane puts an instrumented, self-inflating balloon on the track ahead of the tornado. The uninflated balloon waits until the tornado closes to, typically, 750 meters; then it quickly inflates and spirals up and into the core, taking roughly 3 minutes. Since the drive to the center is automatically produced by the radial pressure gradient, a proper launch radius is the only guidance requirement.

Comparing reactions to two severe tornadoes in one Oklahoma community.

PubMed

Comstock, R Dawn; Mallonee, Sue

2005-09-01

The authors compared the effect of the 3 May 1999 F5 and 8 May 2003 F3 tornadoes on the community of Moore, Oklahoma, by canvassing damaged areas after both tornadoes and surveying residents. Significantly more 1999 than 2003 residents reported property damage and injuries. Television and tornado sirens were the most common warnings each year, however, more 1999 residents received and responded to television warnings. Importantly, storm shelters were used more frequently in 2003. Fifty-one per cent of residents who experienced both tornadoes took the same amount of protective action in 2003 as they had in 1999; 22% took less; and 27% took more. Residents who took less action said that the reason for doing so was inadequate warning and shelter. First-hand experience of tornadoes prompts people to heed warnings when adequate notification is received and to take effective protective action when adequate shelter is available.

Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bluestein, H.B.; LaDue, J.G.; Stein, H.

1993-03-01

Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almostmore » 20 years by NSSL`s fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.« less

Doppler-radar wind-speed measurements in tornadoes: A comparison of real and simulated spectra

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bluestein, H.B.; LaDue, J.G.; Stein, H.

1993-01-01

Bluestein and Unruh have discussed the advantages of using a portable doppler radar to map the wind field in tornadoes. during the spring of 1991 a storm-intercept team from the University of Oklahoma (OU) collected data near five supercell tornadoes in Oklahoma and Kansas. Details about the 1-W, 3-cm, 5-deg half-power beamwidth, CW/FM-CW Doppler radar we used and the methods of data collection and analysis are found in Bluestein and Unruh and Bluestein et al. Using the portable radar, we approximately doubled in only one year the number of tornado spectra that had been collected over a period of almostmore » 20 years by NSSL's fixed-site Doppler radar. In this paper we will compare observed tornado wind spectra with simulated wind spectra (Zmic and Doviak 1975) in order to learn more about tornado structure.« less

The Relationship between Tornado Reports and Cloud-to-Ground Lightning Polarity in the Southeastern United States during the Cool Season from 1989 to 2002

NASA Astrophysics Data System (ADS)

Carey, L. D.; Butts, D. A.

2006-12-01

Several past case and climatological studies have analyzed the relationship between tornadogenesis and cloud-to-ground (CG) lightning polarity. In particular, there has been an emphasis on investigating when and under what environmental and storm conditions tornadoes are associated with anomalous positive CG lightning in order to understand cloud electrification mechanisms and to explore tornado nowcasting opportunities using National Lightning Detection Network (NLDN) CG lightning data. Most of the case and all of the climatological studies have been conducted during the warm season (April to September). In the southeastern United States, a significant number of tornadoes occur in the cool season (October to March). To address this gap in our climatological knowledge, we extend past research by determining the NLDN ground flash properties, including polarity, flash density, peak current, and multiplicity, in the vicinity of tornado reports during the cool season from 1989 2002 in the southeastern United States (i.e., from 102 to 72 degrees west longitude and from 24 to 42 degrees north latitude). Following past studies, we examined NLDN CG lightning properties within 50 km and one hour prior to all tornado reports (i.e., F0 - F5 on the Fujita damage scale). Interestingly, no NLDN detected ground flash activity occurred in the vicinity of 967 (29 %) of the 3325 tornado reports in our sample. Only 10 % (236) of the remaining 2358 tornado reports were associated with predominately (> 50 %) positive CG (PPCG) lightning activity. About 25 % (598) of the tornado reports accompanied by ground flash activity were associated with > 25 % positive CG polarity. In our analysis domain, the geographic frequency maximum of tornadoes accompanied by PPCG lightning activity occurred in a north-south oriented region centered on central Kansas that extended northward into Nebraska and southward into Oklahoma. In this preferred region, 30 % to 60 % of all cool season tornado reports were associated with PPCG lightning activity. Secondary frequency maxima of tornadoes accompanied by PPCG lightning occurred from Louisiana to North Carolina in an arc that followed about 100 to 200 km inland from the coast. From North Carolina to Georgia, the secondary maxima were also downwind of the southern Appalachian Mountains. Another secondary frequency maximum in tornado PPCG activity was centered over northern Florida. However, the percentage of tornadoes associated with PPCG lightning activity over these secondary frequency maxima was typically less than 10 %. Interestingly, this percentage was slightly elevated (10 % to 20 %) over North Carolina on the lee side of the Appalachian Mountains. Additional results will be presented and implications of this study will be discussed.

Investigation into the Formation, Structure, and Evolution of an EF4 Tornado in East China Using a High-Resolution Numerical Simulation

NASA Astrophysics Data System (ADS)

Yao, Dan; Xue, Haile; Yin, Jinfang; Sun, Jisong; Liang, Xudong; Guo, Jianping

2018-04-01

Devastating tornadoes in China have received growing attention in recent years, but little is known about their formation, structure, and evolution on the tornadic scale. Most of these tornadoes develop within the East Asian monsoon regime, in an environment quite different from tornadoes in the U.S. In this study, we used an idealized, highresolution (25-m grid spacing) numerical simulation to investigate the deadly EF4 (Enhanced Fujita scale category 4) tornado that occurred on 23 June 2016 and claimed 99 lives in Yancheng, Jiangsu Province. A tornadic supercell developed in the simulation that had striking similarities to radar observations. The violent tornado in Funing County was reproduced, exceeding EF4 (74 m s-1), consistent with the on-site damage survey. It was accompanied by a funnel cloud that extended to the surface, and exhibited a double-helix vorticity structure. The signal of tornado genesis was found first at the cloud base in the pressure perturbation field, and then developed both upward and downward in terms of maximum vertical velocity overlapping with the intense vertical vorticity centers. The tornado's demise was found to accompany strong downdrafts overlapping with the intense vorticity centers. One of the interesting findings of this work is that a violent surface vortex was able to be generated and maintained, even though the simulation employed a free-slip lower boundary condition. The success of this simulation, despite using an idealized numerical approach, provides a means to investigate more historical tornadoes in China.

Tornado Chasing.

ERIC Educational Resources Information Center

Faidley, Warren

1991-01-01

Presents the rationale and purposes behind the phenomenon known as storm chasing, as well as the contributions that tornado chasers have made to both scientific knowledge and public safety. Provides statistical information on tornado frequencies and locations and contact addresses for storm chasers. (JJK)

Understanding How Climate Change Could Affect Tornadoes

NASA Astrophysics Data System (ADS)

Elsner, James; Guishard, Mark

2014-11-01

Current understanding of how tornadoes might change with global warming is limited. Incomplete data sets and the small-scale nature of tornadic events make it difficult to draw definitive conclusions. A consensus report on the climate of extreme storms found little evidence of trends in tornado frequency in the United States. However new research suggests a potential climate change footprint on tornadoes. Some of this research was presented at the First International Summit on Tornadoes and Climate Change, hosted by Aegean Conferences. The summit took place at the Minoa Palace in Chania, Greece, from 25 to 30 May 2014. Thirty delegates from eight countries—Greece, the United States, Germany, the United Kingdom, China, Japan, Israel, and Taiwan—participated.

An Analysis of Operational Total Lightning Data During Long-Track Tornadoes

NASA Technical Reports Server (NTRS)

Carcione, Brian C.; Stano, Geoffrey T.

2012-01-01

The 27 April 2011 tornado outbreak brought three distinct waves of tornadic thunderstorms to portions of Mississippi, Alabama, Tennessee, and Georgia, striking the Tennessee Valley of north Alabama and southern Tennessee particularly hard. A total of 42 tornado paths were surveyed across the fourteen county area covered by the National Weather Service (NWS) forecast office in Huntsville, Alabama. Ten of these tornadoes were on the ground for at least 20 miles, two had total path lengths over 130 miles, and six tornadoes were classified as violent (EF-4 or EF-5 on the Enhanced Fujita Scale). Many of these tornadoes occurred within the domain of the North Alabama Lightning Mapping Array (NALMA), a ground-based total lightning detection network owned and operated by the NASA Marshall Space Flight Center. Since 2003, the NASA Short-term Prediction Research and Transition Center has supplied data from NALMA in real time to NWS forecast offices in Huntsville, Knoxville/Tri-Cities, Birmingham, and Nashville. Previous research has documented the utility of total lightning information in predicting tornadogenesis, particularly when combined with other remote sensing tools. Basic warning decision-making during events such as 27 April is not the most difficult part of the process; instead, the focus of warning meteorologists shifts to looking for changes in intensity or possible particularly dangerous situations, since doppler radar velocity data often cannot distinguish between weak and strong tornadoes. To that end, this research attempts to determine if any correlation exists between flash densities of the longest-tracked tornadoes over time, and the surveyed wind speeds of the tornadoes. The long-track EF-5 tornado which struck the Hackleburg, Phil Campbell, and Tanner communities in north Alabama was the primary focus of this research due to its intensity and extended life cycle. However, not all tornadoes were available for total lightning analysis due to widespread power outages which negatively affected the detection efficiency and operation of the NALMA. Therefore, additional storms from 2008-2010 with tracks of at least 20 miles were analyzed for comparison purposes.

7 CFR 1945.6 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

..., tornado, storm, flood, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic eruption... hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic..., earthquake, hurricane or tornado. (B) A single storm, or series of storms, accompanied by severe hail...

7 CFR 1945.6 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

..., tornado, storm, flood, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic eruption... hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic..., earthquake, hurricane or tornado. (B) A single storm, or series of storms, accompanied by severe hail...

7 CFR 1945.6 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

..., tornado, storm, flood, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic eruption... hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave, tsunami, earthquake, volcanic..., earthquake, hurricane or tornado. (B) A single storm, or series of storms, accompanied by severe hail...

ASTER Sees Path of Destruction from Joplin, Mo. Tornado

NASA Image and Video Library

2011-05-31

On May 30, 2011, a week after an EF-5 tornado swept through the city of Joplin, Mo, NASA Terra spacecraft captured this image showing the track of the deadly tornado through the city shown horizontally in green-blue.

Disaster Relief: Oklahoma Tornadoes

Science.gov Websites

as citizen soldiers and airmen serving their communities. Story Oklahoma Airman Experiences Moore , Okla. Video Video: Guard Tornado Response Defines "Citizen Soldier" Guard Tornado Response Defines "Citizen Soldier" More Videos Interview with BG Emery Fountain on National Guard

US regional tornado outbreaks and their links to spring ENSO phases and North Atlantic SST variability

NASA Astrophysics Data System (ADS)

Lee, Sang-Ki; Wittenberg, Andrew T.; Enfield, David B.; Weaver, Scott J.; Wang, Chunzai; Atlas, Robert

2016-04-01

Recent violent and widespread tornado outbreaks in the US, such as occurred in the spring of 2011, have caused devastating societal impact with significant loss of life and property. At present, our capacity to predict US tornado and other severe weather risk does not extend beyond seven days. In an effort to advance our capability for developing a skillful long-range outlook for US tornado outbreaks, here we investigate the spring probability patterns of US regional tornado outbreaks during 1950-2014. We show that the four dominant springtime El Niño-Southern Oscillation (ENSO) phases (persistent versus early-terminating El Niño and resurgent versus transitioning La Niña) and the North Atlantic sea surface temperature tripole variability are linked to distinct and significant US regional patterns of outbreak probability. These changes in the probability of outbreaks are shown to be largely consistent with remotely forced regional changes in the large-scale atmospheric processes conducive to tornado outbreaks. An implication of these findings is that the springtime ENSO phases and the North Atlantic SST tripole variability may provide seasonal predictability of US regional tornado outbreaks.

Tornado Mechanics

NASA Technical Reports Server (NTRS)

1976-01-01

The Nimbus and other weather satellites are helping determine why and how tornadoes form their structure and dynamics and ultimately how they can be prevented or artificially dissipated. NASA's Marshall Space Flight Center is also planning a cooperative research program later this year with the University of Arkansas to investigate how tornado damage occurs, and to develop tornado resistant building designs. Hardware and field-data collection are funded by the Technology Utilization Office while data reduction is being performed by the National Oceanic and Atmospheric Administration.

Tornado risks and design windspeeds for the Oak Ridge Plant Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1975-08-01

The effects of tornadoes and other extreme winds should be considered in establishing design criteria for structures to resist wind loads. Design standards that are incorporated in building codes do not normally include the effects of tornadoes in their wind load criteria. Some tornado risk models ignore the presence of nontornadic extreme winds. The purpose of this study is to determine the probability of tornadic and straight winds exceeding a threshold value in the geographical region surrounding the Oak Ridge, Tennessee plant site.

Predictors for people's response to a tornado warning: Arkansas, 1 March 1997.

PubMed

Balluz, L; Schieve, L; Holmes, T; Kiezak, S; Malilay, J

2000-03-01

On 1 March 1997, powerful tornadoes touched down in Arkansas (USA) on a Saturday afternoon. Twenty-six fatalities and 400 non-fatal injuries were reported. We performed a population-based cross-sectional study to determine factors associated with appropriate responses to tornado warnings. Of 146 survey participants, 140 (96 per cent) knew the difference between 'tornado watch' and 'tornado warning' and were aware of when the warning was announced. Of those 140 participants, 64 (45.7 per cent) responded to the warning by seeking shelter, and 58 (90.6 per cent) of those 64 acted within five minutes of hearing the warning. Four factors were positively associated with those seeking shelter: having graduated from high school (OR = 4.2, 95 per cent CI = 1.1-15.5); having a basement in one's house (OR = 3.8, 95 per cent exact CI = 1.1-17.1); hearing a siren (OR = 4.4, 95 per cent CI = 1.3-18.9); and having prepared a household plan of response when tornadoes occur (OR = 2.6, 95 per cent CI = 1.1-6.3). On the basis of these findings, we recommend: first, that people who live in tornadoprone areas have a personal plan of action to help them respond immediately to warnings; second, public-health education officials in areas with frequent tornadic activity should do more to educate the public about what they can do to protect themselves from a tornado; and third, that emergency-management officials planning protection measures for vulnerable communities should consider that most people have limited time (our study documented five minutes) in which to respond to a tornado warning. Thus, shelters in tornado-prone areas should be quickly accessible by residents.

Twitter as a Potential Disaster Risk Reduction Tool. Part III: Evaluating Variables that Promoted Regional Twitter Use for At-risk Populations During the 2013 Hattiesburg F4 Tornado.

PubMed

Cooper, Guy Paul; Yeager, Violet; Burkle, Frederick M; Subbarao, Italo

2015-06-29

Study goals attempt to identify the variables most commonly associated with successful tweeted messages and determine which variables have the most influence in promoting exponential dissemination of information (viral spreading of the message) and trending (becoming popular) in the given disaster affected region. Part II describes the detailed extraction and triangulation filtration methodological approach to acquiring twitter data for the 2013 Hattiesburg Tornado. The data was then divided into two 48 hour windows before and after the tornado impact with a 2 hour pre-tornado buffer to capture tweets just prior to impact. Criteria-based analysis was completed for Tweets and users. The top 100 pre-Tornado and post-Tornado retweeted users were compared to establish the variability among the top retweeted users during the 4 day span.  Pre-Tornado variables that were correlated to higher retweeted rates include total user tweets (0.324), and total times message retweeted (0.530).  Post-Tornado variables that were correlated to higher retweeted rates include total hashtags in a retweet (0.538) and hashtags #Tornado (0.378) and #Hattiesburg (0.254). Overall hashtags usage significantly increased during the storm. Pre-storm there were 5,763 tweets with a hashtag and post-storm there was 13,598 using hashtags. Twitter's unique features allow it to be considered a unique social media tool applicable for emergency managers and public health officials for rapid and accurate two way communication.  Additionally, understanding how variables can be properly manipulated plays a key role in understanding how to use this social media platform for effective, accurate, and rapid mass information communication.

Doppler Radar and Cloud-to-Ground Lightning Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Buechler, Dennis; Cammarata, Michael; Arnold, James E. (Technical Monitor)

2002-01-01

Data from a single WSR-88D Doppler radar and the National Lightning Detection Network are used to examine the characteristics of the convective storms that produced a severe tornado outbreak within Tropical Storm Beryl's remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 12 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 hours, spawning tornadoes over a time period spanning approximately 6.5 hours. Time-height analyses of the three strongest supercells are presented in order to document storm kinematic structure and evolution. These Beryl mini-supercells were comparable in radar-observed intensity but much more persistent than other tropical cyclone-spawned tornadic cells documented thus far with Doppler radars. Cloud-to-ground lightning data are also examined for all the tornadic cells in this severe swarm-type tornado outbreak. These data show many of the characteristics of previously reported heavy-precipitation supercells. Lightning rates were weak to moderate, even in the more intense supercells, and in all the storms the lightning flashes were almost entirely negative in polarity. No lightning at all was detected in some of the single-tornado storms. In the stronger cells, there is some evidence that lightning rates can decrease during tornadogenesis, as has been documented before in some midlatitude tornadic storms. A number of the storms spawned tornadoes just after producing their final cloud-to-ground lightning flashes. These findings suggest possible benefits from implementation of observing systems capable of monitoring intracloud as well as cloud-to-ground lightning activity.

Twitter as a Potential Disaster Risk Reduction Tool. Part III: Evaluating Variables that Promoted Regional Twitter Use for At-risk Populations During the 2013 Hattiesburg F4 Tornado

PubMed Central

Cooper, Guy Paul; Yeager, Violet; Burkle, Frederick M.; Subbarao, Italo

2015-01-01

Introduction: Study goals attempt to identify the variables most commonly associated with successful tweeted messages and determine which variables have the most influence in promoting exponential dissemination of information (viral spreading of the message) and trending (becoming popular) in the given disaster affected region. Methods: Part II describes the detailed extraction and triangulation filtration methodological approach to acquiring twitter data for the 2013 Hattiesburg Tornado. The data was then divided into two 48 hour windows before and after the tornado impact with a 2 hour pre-tornado buffer to capture tweets just prior to impact. Criteria-based analysis was completed for Tweets and users. The top 100 pre-Tornado and post-Tornado retweeted users were compared to establish the variability among the top retweeted users during the 4 day span.  Results: Pre-Tornado variables that were correlated to higher retweeted rates include total user tweets (0.324), and total times message retweeted (0.530).  Post-Tornado variables that were correlated to higher retweeted rates include total hashtags in a retweet (0.538) and hashtags #Tornado (0.378) and #Hattiesburg (0.254). Overall hashtags usage significantly increased during the storm. Pre-storm there were 5,763 tweets with a hashtag and post-storm there was 13,598 using hashtags. Conclusions: Twitter’s unique features allow it to be considered a unique social media tool applicable for emergency managers and public health officials for rapid and accurate two way communication.  Additionally, understanding how variables can be properly manipulated plays a key role in understanding how to use this social media platform for effective, accurate, and rapid mass information communication.  PMID:26203397

A database about the tornadic activity in Catalonia (NE Spain) since 1994

NASA Astrophysics Data System (ADS)

Morales, M. E.; Arús, J.; Llasat, M. C.; Castán, S.

2009-09-01

Although tornadic activity is not the most important hazard in Spain, the damages that tornadoes and downburst generate are considerable in urban areas, giving place in some occasions to casualties. In Spain, the oldest systematic works collecting data about tornadoes, refer to the Balearic Islands, although some series about tornadoes in Spain have also been collected and analysed (Gayà, 2005). These series shows a positive increase that is probably more related to a change in the perception level of the population than to climatic change. In some occasions it is difficult to separate the damages produced by the tornado itself from those produced by other associated hazards like heavy rains, hail or a wind storms. It was the case of the September 2006 event, in which flash floods and tornadoes were recorded. In the same sense in some occasions, damages produced by a downsburt are confused with those that produced by a tornado. Having in mind all these facts, having a good systematic data base about tornadoes is necessary, before to obtain some conclusions not enough justified. This kind of database is not easy to obtain, because of it requires to have detailed information about damages, meteorological observations and testimonies that has to be filtered by a good quality control. After a general presentation about tornadoes and downsbursts in Mediterranean Region, this contribution presents the database that have affected Catalonia during the period 1994-2009, starting with the tornado recorded on the Espluga de Francolí the 31 August 1994.This database has been built in basis to the AEMET information, the Consorcio de Compensación de Seguros (the insurance company of Spain for natural disasters), the newspapers and field visits to the affected places.

Case study of the March 24, 1976 Elton, Louisiana tornado using satellite infrared imagery, Doppler sounder, rawinsonde, and radar observations

NASA Technical Reports Server (NTRS)

Hung, R. J.; Smith, R. E.

1983-01-01

The Elton, Louisiana tornado on March 24, 1976 has been studied using GOES digital infrared data for the growth and collapse of the cloud top, the temperature-height relationship and air mass instability from rawinsonde data, gravity waves from Doppler sounder records, and radar summaries from storm activity during the three-hour time period immediately preceding the touchdown of the tornado. In this case, the overshooting turret collapsed 30 minutes before the tornado touchdown as the eastward moving cloud reached Elton, Louisiana. Results show that the gravity waves were excited by the enhanced convection of the storm penetrating through the tropopause in the 2.5 hour time period before the tornado touched down.

Case study of the March 24, 1976 Elton, Louisiana tornado using satellite infrared imagery, doppler sounder, rawinsonde, and radar observations

NASA Astrophysics Data System (ADS)

Hung, R. J.; Smith, R. E.

1983-05-01

The Elton, Louisiana tornado on March 24, 1976 has been studied using GOES digital infrared data for the growth and collapse of the cloud top, the temperature-height relationship and air mass instability from rawinsonde data, gravity waves from Doppler sounder records, and radar summaries from storm activity during the three-hour time period immediately preceding the touchdown of the tornado. In this case, the overshooting turret collapsed 30 minutes before the tornado touchdown as the eastward moving cloud reached Elton, Louisiana. Results show that the gravity waves were excited by the enhanced convection of the storm penetrating through the tropopause in the 2.5 hour time period before the tornado touched down.

7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Administrator, including, but not limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic... Administrator, including, but not limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic... wind, flood, hurricane, tidal surge, tornado, volcanic eruption, and wildfire. (h) For honeybee colony...

7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Administrator, including, but not limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic... Administrator, including, but not limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic... wind, flood, hurricane, tidal surge, tornado, volcanic eruption, and wildfire. (h) For honeybee colony...

7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic eruption, wildfire on non-Federal... to, blizzard, flood, hurricane, tidal surge, tornado, volcanic eruption, wildfire on non-Federal land... limited to, earthquake, excessive wind, flood, hurricane, tidal surge, tornado, volcanic eruption, and...

7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic eruption, wildfire on non-Federal... to, blizzard, flood, hurricane, tidal surge, tornado, volcanic eruption, wildfire on non-Federal land... limited to, earthquake, excessive wind, flood, hurricane, tidal surge, tornado, volcanic eruption, and...

7 CFR 760.203 - Eligible losses, adverse weather, and other loss conditions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... limited to, blizzard, flood, hurricane, tidal surge, tornado, volcanic eruption, wildfire on non-Federal... to, blizzard, flood, hurricane, tidal surge, tornado, volcanic eruption, wildfire on non-Federal land... limited to, earthquake, excessive wind, flood, hurricane, tidal surge, tornado, volcanic eruption, and...

Dynamical Analysis and Visualization of Tornadoes Time Series

PubMed Central

2015-01-01

In this paper we analyze the behavior of tornado time-series in the U.S. from the perspective of dynamical systems. A tornado is a violently rotating column of air extending from a cumulonimbus cloud down to the ground. Such phenomena reveal features that are well described by power law functions and unveil characteristics found in systems with long range memory effects. Tornado time series are viewed as the output of a complex system and are interpreted as a manifestation of its dynamics. Tornadoes are modeled as sequences of Dirac impulses with amplitude proportional to the events size. First, a collection of time series involving 64 years is analyzed in the frequency domain by means of the Fourier transform. The amplitude spectra are approximated by power law functions and their parameters are read as an underlying signature of the system dynamics. Second, it is adopted the concept of circular time and the collective behavior of tornadoes analyzed. Clustering techniques are then adopted to identify and visualize the emerging patterns. PMID:25790281

Dynamical analysis and visualization of tornadoes time series.

PubMed

Lopes, António M; Tenreiro Machado, J A

2015-01-01

In this paper we analyze the behavior of tornado time-series in the U.S. from the perspective of dynamical systems. A tornado is a violently rotating column of air extending from a cumulonimbus cloud down to the ground. Such phenomena reveal features that are well described by power law functions and unveil characteristics found in systems with long range memory effects. Tornado time series are viewed as the output of a complex system and are interpreted as a manifestation of its dynamics. Tornadoes are modeled as sequences of Dirac impulses with amplitude proportional to the events size. First, a collection of time series involving 64 years is analyzed in the frequency domain by means of the Fourier transform. The amplitude spectra are approximated by power law functions and their parameters are read as an underlying signature of the system dynamics. Second, it is adopted the concept of circular time and the collective behavior of tornadoes analyzed. Clustering techniques are then adopted to identify and visualize the emerging patterns.

Characteristics of Tornado-Like Vortices Simulated in a Large-Scale Ward-Type Simulator

NASA Astrophysics Data System (ADS)

Tang, Zhuo; Feng, Changda; Wu, Liang; Zuo, Delong; James, Darryl L.

2018-02-01

Tornado-like vortices are simulated in a large-scale Ward-type simulator to further advance the understanding of such flows, and to facilitate future studies of tornado wind loading on structures. Measurements of the velocity fields near the simulator floor and the resulting floor surface pressures are interpreted to reveal the mean and fluctuating characteristics of the flow as well as the characteristics of the static-pressure deficit. We focus on the manner in which the swirl ratio and the radial Reynolds number affect these characteristics. The transition of the tornado-like flow from a single-celled vortex to a dual-celled vortex with increasing swirl ratio and the impact of this transition on the flow field and the surface-pressure deficit are closely examined. The mean characteristics of the surface-pressure deficit caused by tornado-like vortices simulated at a number of swirl ratios compare well with the corresponding characteristics recorded during full-scale tornadoes.

Numerical simulation of intense multi-scale vortices generated by supercell thunderstorms

NASA Astrophysics Data System (ADS)

Finley, Catherine Ann

1998-11-01

A nested grid primitive equation model (RAMS version 3b) is used to study various aspects of tornadoes and the thunderstorms that produce them. A unique aspect of these simulations is that the model was initialized with synoptic data, and telescoping grids allow atmospheric flows ranging from the synoptic-scale down to sub- tornado-scale vortices to be represented in the model. Two different case studies were simulated in this study: June 30, 1993, and May 15, 1991. The June 30, 1993, simulation produced a classical supercell storm which developed at the intersection between a stationary front and an outflow boundary generated by previous convection. As the simulation progressed, additional storms developed west of the main storm along the stationary front. One of these storms interacted with the main storm to produce a single supercell storm. This storm had many characteristics of a high-precipitation (HP) supercell, and eventually evolved into a bow-echo. The transition of the storm into a bow-echo is discussed and possible physical processes responsible for the transition are presented. The June 30, 1993, simulated supercell produced two weak tornadoes. The first tornado developed along the flanking line of the storm to the southeast of the mesocyclone. The second tornado developed along a strong horizontal shear zone beneath the rotating comma-head structure of the HP supercell. Neither tornado was clearly linked to the mesocyclone in the parent storm, and both tornadoes formed first near the surface and then developed upward with time. Circulation and vorticity analyses were used to investigate the tornadogenesis process in this case. Results from these analyses indicated that the circulation associated with both tornadoes was already present at low-levels in the storm environment 15-20 minutes before the tornadoes developed. Although the baroclinic term associated with the downdraft air made a negligible contribution to the circulation in this case, the downdraft played an important role in tilting horizontal vorticity into the vertical just above the surface in the near tornado environment where horizontal convergence could then act to amplify it. A comparison with the proposed tornadogenesis process(es) in classical supercells is also presented. The May 15, 1991, simulation produced a classical supercell which developed along the dryline in the Texas panhandle. This supercell in turn produced a tornado which lasted for 50 minutes in the simulation. During a ten minute period toward the end of the simulation, six secondary vortices developed within the main tornado vortex. The simulated secondary vortices had many features in common with multiple-vortex tornadoes and secondary vortices produced in laboratory vortices. The evolution and structure of the simulated secondary vortices is presented, and physical mechanisms responsible for their development and dissipation are discussed.

The application of UAS towards tornado research and forecasting

NASA Astrophysics Data System (ADS)

Houston, A. L.; Argrow, B. M.; Frew, E.; Weiss, C.

2014-12-01

UAS hold significant potential to advance the understanding of tornadoes and improve tornado warning skill. While the current regulatory environment places limits on the application of UAS towards these ends, demonstrated success targeting tornadic and non-tornadic supercells proves the general feasibility of this work. In this presentation we will summarize the successes using UAS to collect data in the vicinity of supercell thunderstorms and discuss ways that these data, along with additional data collected in future field campaigns, can be used answer basic research questions concerning tornado formation and applied research questions concerning the value of UAS in the tornado warning decision process. The associative relationship between the rear-flank downdraft (RFD) and tornadogenesis has long been recognized. Yet, despite decades of research focused on tornadoes, the causal relationship between the RFD and tornadogenesis remains unresolved. In the presentation, we will describe ways that UAS could be used to test hypotheses posed to explain this causal relationship. We will also present a strategy to quantify the impact of UAS on tornado warning skill. Through controlled forecast experiments conducted using data collected through small field campaigns that leverage prior success targeting supercell thunderstorms with UAS, the value of targeted surveillance of potentially tornadic storms using UAS can be assessed. Significant changes to the existing regulatory environment are likely required for UAS, operated in a targeted surveillance mode, to contribute to improving tornado warning skill, but progress can be made today towards quantifying the impact that UAS could make.

Cold-Season Tornadoes: Climatological, Meteorological, and Social Perspectives

NASA Astrophysics Data System (ADS)

Childs, Samuel J.

Tornadoes that occur during the cold season, defined here as November-February (NDJF), pose many unique societal risks. For example, people can be caught off-guard because in general one does not expect severe weather and tornadoes during winter months. The public can also be unsuspecting of significant weather due to the bustle of major holidays like Thanksgiving, Christmas, and New Year's, when most people are concerned with family activities and not thinking about the weather. Cold-season tornadoes also have a propensity to be nocturnal and occur most frequently in the South and Southeastern U.S., where variable terrain, inadequate resources, and a relatively high mobile home density add additional social vulnerabilities. Over the period 1953-2015 within a study domain of (25-42.5°N, 75-100°W), some 937 people lost their lives as a result of NDJF tornadoes. Despite this enhanced societal risk of cold-season tornadoes in the South, very little attention has been given to their meteorological characteristics and climate patterns, and public awareness of their potential impacts is lacking. This thesis aims to greatly advance the current state of knowledge of NDJF tornadoes by providing an in-depth investigation from three different science perspectives. First, a climatology of all (E)F1-(E)F5 NDJF tornadoes is developed, spanning the period 1953-2015 within a domain of (25-42.5°N, 75-100°W), in order to assess frequency and spatial changes over time. A large increasing trend in cold-season tornado occurrence is found across much of the Southeastern U.S., with the greatest uptick in Tennessee, while a decreasing trend is found across eastern Oklahoma. Spectral analysis reveals a cyclic pattern of enhanced NDJF counts every 3-7 years, coincident with the known period for ENSO. Indeed, La Nina episodes are found to be correlated with NDJF tornado counts, although a stronger teleconnection correlation exists with the Arctic Oscillation (AO), which explains 25% of the variance in counts. A second perspective focuses on meteorological environments that characterize NDJF tornadoes through use of the NCEP/NCAR Reanalysis. Upon comparing the most tornadic and least tornadic cold seasons, it is found that active seasons are characterized by a large trough in the western U.S.; warm and moist conditions across the Southeast, likely due to an enhanced low-level jet transport from the western Gulf of Mexico; and enhanced 1000-500-hPa wind speed shear. The third perspective addressed in this thesis is that of social science. A case study of four tornado events from November 2016-February 2017, in which a post-event survey is disseminated to NWS meteorologists, broadcast meteorologists, and emergency managers, is carried out to assess strategies and barriers professionals face when communicating cold-season tornado risk and warnings to their respective communities. The survey also aims to shed light on the perceived levels of human preparedness, vulnerability, and resiliency from the professional's point of view. In addition to unique, case-specific challenges, the professionals expressed major barriers to communication due to inconsistency of messages and graphics, and an inability to give the public information on fine enough temporal and spatial scales. Each decision-making sector noted a high local vulnerability to tornadoes in general, mostly brought on by lack of education and/or resources. However, most professionals perceive their communities to be aware of cold-season tornado risk and thus adequately prepared and resilient when they occur. The survey results also confirm the desire and need for better collaboration among professionals, and with social scientists, in order to adequately educate and warn all sectors of society from tornado risk, especially those during times of year they are not typically expected. Harnessing all three perspectives presented in this study provides a much deeper understanding of NDJF tornadoes and their societal impacts, an understanding that serves to increase public awareness and ultimately save lives.

Shelter from the Storm.

ERIC Educational Resources Information Center

Schultz, Corey; Metz, John

2001-01-01

Discusses why most schools need to upgrade the spaces they use to protect students and staff from tornadoes. School building areas commonly used as safe havens during tornadoes are assessed, followed by information on disaster damage reimbursements and Federal Emergency Management Agency guidelines (FEMA 361) for building tornado and hurricane…

Maryland: La Plata

Atmospheric Science Data Center

2014-05-15

article title:  Tornado Cuts Through La Plata, Maryland     View Larger Image A category F4 tornado tore through La Plata, Maryland on April 28, 2002, killing 5 and ... illustrates the strip of flattened vegetation left by the tornado. The lower image was acquired by MISR's nadir (vertical-viewing) ...

Recovery from major storms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holeman, J.S.

1980-01-01

Public Service Company of Oklahoma's transmission and distribution system is in tornado alley, and it seems the number of tornados hitting some part of the system is increasing each year. In the past 30 years, Tulsa his been hit 7 times, and experienced 3 very wide and destructive tornado storm systems between 1971 and 1975.

Community Post-Tornado Support Groups: Intervention and Evaluation.

ERIC Educational Resources Information Center

McCammon, Susan; And Others

Post-tornado support groups were organized by the Greene County, North Carolina disaster coordinators and the Pitt County outreach workers from the Community Mental Health Center sponsored tornado follow-up project. The most significant intervention used was the emphasis on creating a climate of group support by establishing a forum for…

Factors in Perception of Tornado Hazard: An Exploratory Study.

ERIC Educational Resources Information Center

de Man, Anton; Simpson-Housley, Paul

1987-01-01

Administered questionnaire on tornado hazard to 142 adults. Results indicated that subject's gender and education level were best predictors of perceived probability of tornado recurrence; that ratings of severity of potential damage were related to education level; and that gender accounted for significant percentage of variance in anxiety…

Luminous electrical phenomena in Huntsville, Alabama, tornadoes on April 3, 1974

NASA Technical Reports Server (NTRS)

Vaughan, O. H., Jr.; Vonnegut, B.

1976-01-01

Unusual lightning and varicolored luminous phenomena were observed on the evening of April 3, 1974, when severe tornadoes passed through Madison County, Alabama. Photographs and eyewitness accounts of this electrical activity are related to the trajectories of the tornadoes and the damage areas they produced.

Some New Ideas About Tornadoes

ERIC Educational Resources Information Center

Weigel, Edwin P.

1975-01-01

Based on the assumption that if occupants of buildings knew which places in these buildings were relatively safe in disasters such as tornadoes, and if they had sufficient warning, architects and engineers feel there is a significant opportunity to advance the art of school (or building) design to provide tornado-protected areas. (EB)

Health Information in Modern Standard Arabic (Arabic dialect) (العربية الفصحى, عربي فصيح)

MedlinePlus

... Standard Arabic (Arabic dialect)) MP4 Healthy Roads Media Tornadoes - English MP3 Tornadoes - العربية الفصحى, عربي فصيح (Modern Standard Arabic (Arabic dialect)) MP3 Tornadoes - English MP4 Tornadoes - العربية الفصحى, عربي فصيح (Modern ...

US tornadoes. Part 1: 70-year statistics

NASA Technical Reports Server (NTRS)

Fujita, T. T.

1987-01-01

If tornadoes were counted as the Gross National Product, no other country on the surface of the earth could come even close to the United States. During the recent 70 year period, the United States produced 31,054 tornadoes which left behind a cumulative path of 132,005 miles (212,396 km) which would circle the world 5.3 times along the equator. In completing the book, staff members of the Satellite and Mesometeorlogy Research Project (1961 to the present) played an important role in collecting, evaluating, and archiving the historical tornado data.

Tornado protection by venting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cavanagh, C.A.

1987-01-01

The purpose of this paper is to demonstrate the ability to protect a modern nuclear power plant from the effects of a tornado by the use of a system of venting in all safety-related structures outside of the containment. The paper demonstrates this by presenting a method of analysis and of equipment selection that fully complies with the intent and the letter of applicable federal regulatory guides. A report of an actual tornado in the City of Kalamazoo, Michigan, suggests that the concept of sealing a plant during a tornado may not always be applicable.

Underwater gas tornado

NASA Astrophysics Data System (ADS)

Byalko, Alexey V.

2013-07-01

We present the first experimental observation of a new hydrodynamic phenomenon, the underwater tornado. Simple measurements show that the tornado forms a vortex of the Rankine type, i.e. the rising gas rotates as a solid body and the liquid rotates with a velocity decreasing hyperbolically with the radius. We obtain the dependence of the tornado radius a on the gas stream value j theoretically: a ∼ j2/5. Processing of a set of experiments yielded the value 0.36 for the exponent in this expression. We also report the initial stages of the theoretical study of this phenomenon.

A solar tornado caused by flares

NASA Astrophysics Data System (ADS)

Panesar, N. K.; Innes, D. E.; Tiwari, S. K.; Low, B. C.

2014-01-01

An enormous solar tornado was observed by SDO/AIA on 25 September 2011. It was mainly associated with a quiescent prominence with an overlying coronal cavity. We investigate the triggering mechanism of the solar tornado by using the data from two instruments: SDO/AIA and STEREO-A/EUVI, covering the Sun from two directions. The tornado appeared near to the active region NOAA 11303 that produced three flares. The flares directly influenced the prominence-cavity system. The release of free magnetic energy from the active region by flares resulted in the contraction of the active region field. The cavity, owing to its superior magnetic pressure, expanded to fill this vacated space in the corona. We propose that the tornado developed on the top of the prominence due to the expansion of the prominence-cavity system.

October 1, 1989 tornado at the Savannah River Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, M.J.; Kurzeja, R.J.

1990-01-01

A tornado with wind speeds in the 113 to 157 mph range struck the southern portion of the Savannah River Site near Aiken, SC at around 7:30 pm on October 1, 1989. The tornado was spawned from a severe thunderstorm with a height of 57,000 ft in a warm and humid air mass. Two million dollars in timber damage occurred over 2,500 acres along a ten-mile swath, but no onsite structural damage or personal injury occurred. Tree-fall patterns indicated that some of this damage was the result of thunderstorm downbursts which accompanied the tornado. Ground-based and aerial photography showed bothmore » snapped and mowed over trees which indicate that the tornado was elevated at times. 4 refs., 25 figs., 2 tabs.« less

Mental Health Among Adolescents Exposed to a Tornado: The Influence of Social Support and its Interactions with Socio-Demographic Characteristics and Disaster Exposure

PubMed Central

Paul, Lisa A.; Felton, Julia W.; Adams, Zachary W.; Welsh, Kyleen; Miller, Stephanie; Ruggiero, Kenneth J.

2015-01-01

Approximately 25% of youths experience a natural disaster and many experience disaster-related distress, including symptoms of posttraumatic stress disorder (PTSD) and depression. This study contributes to the literature by examining PTSD and depressive symptoms among 2,000 adolescents (50.9% female, 70.5% White) assessed after exposure to tornadoes in 2011. The authors hypothesized that greater tornado exposure, female sex, and younger age would be associated with distress, and that social support would interact with these associations. Analyses showed that PTSD symptoms were predicted by lower levels of social support (β = −.28, p < .001), greater tornado exposure (β = .14, p<.001), lower household income (β = −.06, p = .013, female sex (β = −.10, p<.001), and older age (β = .07, p = .002), with a 3-way interaction between tornado exposure, sex, and social support (β = −.06, p = .017). For boys, the influence of tornado exposure on PTSD symptoms increased as social support decreased. Regardless of level of tornado exposure, low social support was related to PTSD symptoms for girls; depressive symptom results were similar. These findings are generally consistent with the literature and provide guidance for intervention development focused on strengthening social support at the individual, family, and community levels. PMID:26031997

Mental Health Among Adolescents Exposed to a Tornado: The Influence of Social Support and Its Interactions With Sociodemographic Characteristics and Disaster Exposure.

PubMed

Paul, Lisa A; Felton, Julia W; Adams, Zachary W; Welsh, Kyleen; Miller, Stephanie; Ruggiero, Kenneth J

2015-06-01

Approximately 25% of youths experience a natural disaster and many experience disaster-related distress, including symptoms of posttraumatic stress disorder (PTSD) and depression. This study contributes to the literature by examining PTSD and depressive symptoms among 2,000 adolescents (50.9% female, 70.5% White) assessed after exposure to tornadoes in 2011. The authors hypothesized that greater tornado exposure, female sex, and younger age would be associated with distress, and that social support would interact with these associations. Analyses showed that PTSD symptoms were associated with lower levels of social support (β = -.28, p < .001), greater tornado exposure (β = .14, p < .001), lower household income (β = -.06, p = .013, female sex (β = -.10, p < .001), and older age (β = .07, p = .002), with a 3-way interaction between tornado exposure, sex, and social support (β = -.06, p = .017). For boys, the influence of tornado exposure on PTSD symptoms increased as social support decreased. Regardless of level of tornado exposure, low social support was related to PTSD symptoms for girls; depressive symptom results were similar. These findings were generally consistent with the literature and provide guidance for intervention development focused on strengthening social support at the individual, family, and community levels. © 2015 International Society for Traumatic Stress Studies.

Radar characteristics of tornadic and non-tornadic quasi-linear convective systems over the central United States

NASA Astrophysics Data System (ADS)

Grana, Sarah

Quasi-Linear Convective Systems (QLCS) are linear convective systems known to produce a variety of severe weather threats including damaging winds, hail, flooding, and even tornadoes. Previous studies have found that QLCSs are most common in the Ohio and Mississippi River Valleys and produce roughly 18% of tornadoes across the United States. In addition, it has been shown that QLCS tornadoes spawn from low-level circulations called mesovortices. Mesovortices build quickly from the ground up making it very difficult to accurately identify them on radar, especially at long distances. Therefore, it is imperative that more research be done to distinguish between QLCSs that produce tornadoes and those that do not. Fifty-seven QLCS events were selected to investigate how radar parameters differ between tornadic and non-tornadic QLCSs. These events were broken into the following categories: warm season tornadic, warm season non-tornadic, cold season tornadic, and cold season non-tornadic. Tornadic cases produced one or more tornadoes, while non-tornadic cases had tornado warnings issued without a tornado actually being produced. These events were chosen based on their geographical location and the data available. The goal was to find radar parameters that were statistically significantly different between tornadic events and non-tornadic events.

The typical structure of tornado proximity soundings

NASA Astrophysics Data System (ADS)

Schaefer, Joseph T.; Livingston, Richard L.

1988-05-01

An objective scheme based on empirical orthogonal function analysis to detect patterns in a single or multivariate data set is developed and applied to rawinsonde observations taken in the near-tornado environment. If only temperature data are considered, two distinct categories, differentiated chiefly by the tropopause height, are found. When moisture observations are included with the temperatures, the separation between categories becomes less distinct. However, it is noted that within the near-tornado environment there is an inverse relationship between the degree of observed convective and conditional instability. Analysis of only the winds shows that a low-level veering with height is the rule. However, the strength of the veering can vary considerably. When the temperature, moisture, and winds are treated in concert, two categories again appear. One group occurs with strong winds and a low tropopause, while the other group features weak winds and a high tropopause. These groups correspond to "springtime" and "summertime" synoptic situations, respectively. Comparisons of the various analyses indicate that the near-tornado environment typically features a balance between the strength of the veering of the winds and the amount of conditional instability present. Summer tornadoes feature strong conditional instability and weak winds, while springtime tornadoes occur with stronger veering and convective instability. The strongest tornadoes occur with springtime-type conditions.

Regional Health System Response to the 2007 Greensburg, Kansas, EF5 Tornado.

PubMed

Ablah, Elizabeth; Tinius, Annie M; Konda, Kurt; Synovitz, Carolyn; Subbarao, Italo

2007-11-01

On May 4, 2007 an EF5 tornado hit the rural community of Greensburg, KS, destroying 95% of the town and resulting in 12 fatalities. Data was requested from the emergency medical services units that initially responded and the regional hospitals that received people injured in the tornado within 24 hours following the tornado. Requested data included patient age and sex, and injury severity score or ICD-9 codes. Critical mortality, or the number of deaths of critically injured patients, was also calculated. The extensive damage caused by the tornado effectively destroyed the infrastructure of the community and created enormous challenges for emergency medical services responders, who were unable to record any triage data. Area hospitals treated 90 patients, who had an average injury severity score of 6.4. Age was found to be related to injury severity, but no relationship between sex and injury severity was found. Critical mortality was found to be 18% for this event. Injury severity score has seldom been used to analyze natural disasters, especially tornadoes, although such analysis is helpful for understanding the magnitude of the disaster, comparing to other disasters, and preparing for future incidents. Advanced warning and personal preparedness are important factors in reducing tornado-related injuries and deaths.

Doppler Radar and Lightning Network Observations of a Severe Outbreak of Tropical Cyclone Tornadoes

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Buechler, Dennis; Goodman, Steven; Cammarata, Michael

2003-01-01

Data from a single WSR-88D Doppler radar and the National Lightning Detection Network are used to examine in detail the characteristics of the convective storms that produced a severe tornado outbreak within Tropical Storm Beryl's remnants on 16 August 1994. Comparison of the radar data with reports of tornadoes suggests that only 13 cells produced the 29 tornadoes that were documented in Georgia and the Carolinas on that date. Six of these cells spawned multiple tornadoes, and the radar data confirm the presence of miniature supercells. One of the cells was identifiable on radar for 11 hours, spawning tornadoes over a time period spanning approximately 6.5 hours. Several other tornadic cells also exhibited great longevity, with cell lifetimes greater than ever previously documented in a landfalling tropical cyclone tornado event, and comparable to those found in major midlatitude tornadic supercell outbreaks. Time-height analyses of the three strongest tornadic supercells are presented in order to document storm kinematic structure and to show how these storms appear at different ranges from a WSR-88D radar. In addition, cloud-to-ground (CG) lightning data are examined for the outbreak, the most intense tropical cyclone tornado event studied thus far. Although the tornadic cells were responsible for most of Beryl's CG lightning, flash rates were only weak to moderate, even in the most intense supercells, and in all the tornadic storms the lightning flashes were almost entirely negative in polarity. A few of the single-tornado storms produced no detectable CG lightning at all. In the stronger cells, there is some evidence that CG lightning rates decreased during tornadogenesis, as has been documented before in some midlatitude tornadic storms. A number of the storms spawned tornadoes just after producing their final CG lightning flashes. Surprisingly, both peak currents and positive flash percentages were larger in Beryl s nontornadic storms than in the tornadic ones. Despite some intriguing patterns, the CG lightning behavior in this outbreak remains mostly inconsistent and ambiguous, and offers only secondary value for warning guidance. The present findings argue in favor of the implementation of observing systems capable of continuous monitoring of total lightning activity in storms.

Tornado Intensity Estimated from Damage Path Dimensions

PubMed Central

Elsner, James B.; Jagger, Thomas H.; Elsner, Ian J.

2014-01-01

The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s−1 for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width. PMID:25229242

Tornado intensity estimated from damage path dimensions.

PubMed

Elsner, James B; Jagger, Thomas H; Elsner, Ian J

2014-01-01

The Newcastle/Moore and El Reno tornadoes of May 2013 are recent reminders of the destructive power of tornadoes. A direct estimate of a tornado's power is difficult and dangerous to get. An indirect estimate on a categorical scale is available from a post-storm survery of the damage. Wind speed bounds are attached to the scale, but the scale is not adequate for analyzing trends in tornado intensity separate from trends in tornado frequency. Here tornado intensity on a continuum is estimated from damage path length and width, which are measured on continuous scales and correlated to the EF rating. The wind speeds on the EF scale are treated as interval censored data and regressed onto the path dimensions and fatalities. The regression model indicates a 25% increase in expected intensity over a threshold intensity of 29 m s(-1) for a 100 km increase in path length and a 17% increase in expected intensity for a one km increase in path width. The model shows a 43% increase in the expected intensity when fatalities are observed controlling for path dimensions. The estimated wind speeds correlate at a level of .77 (.34, .93) [95% confidence interval] with a small sample of wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. Research is needed to understand the upward trends in path length and width.

77 FR 4389 - In the Matter of Tornado Gold International Corp., Twin Faces East Entertainment Corp., Universal...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-01-27

... SECURITIES AND EXCHANGE COMMISSION [File No. 500-1] In the Matter of Tornado Gold International Corp., Twin Faces East Entertainment Corp., Universal Ice Blast, Inc., US Farms, Inc., US Microbics... concerning the securities of Tornado Gold International Corp. because it has not filed any periodic reports...

Exploring the Experiences of Special Educators Following the Joplin Tornado

ERIC Educational Resources Information Center

Palmer, Allyson

2013-01-01

On May 22, 2011, an EF5 tornado ripped through Joplin, MO, leaving many residents without homes and destroying or damaging several school buildings. The purpose of this qualitative study was to explore how special education teachers responded to the needs of their students with disabilities following the Joplin tornado. Purposeful sampling was…

Tornado activity at SRP during 1976

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pepper, D.W.; Schubert, J.F.

1978-07-01

Tracks of three small tornadoes were confirmed on the site of the Savannah River Plant during 1976. Only minor damage to buildings and vehicles was experienced. The tornadoes were rated F1 on the Fujita-Pearson scale. Synoptic weather conditions from the National Weather Service and from the SRP seven-tower data system were recorded.

Tornadoes and transmission reliability planning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Teles, J.E.; Anderson, S.W.; Landgren, G.L.

1980-01-01

The objective of this paper is to introduce an analytical approach for predicting overhead transmission line outages that are caused by tornadoes. The method is presently being used to determine the effects of tornadoes on various right-of-way configurations associated with a generating station project or the supply to a major substation. 2 refs.

Observations of the Wind Field in Tornadoes, Funnel Clouds, and Wall Clouds with a Portable Doppler Radar.

NASA Astrophysics Data System (ADS)

Bluestein, H. B.; Unruh, W. P.

1989-12-01

A severe-storm intercept field program was held in Oklahoma and nearby parts of Texas during the 1987-38 spring seasons. The purpose of the experiment was to use, for the first time, a low-power, portable, continuous-wave (CW), 3-cm Doppler radar to obtain wind spectra in tornadoes from a distance of less than 10 km.We discuss measurements of spectra we recorded in a tornado, a funnel cloud, and two wall clouds. Photographic documentation is also given to aid in the interpretation of our data. Wind speeds as high as 60 m s1 were measured in the tornado. It was found that deploying the portable Doppler radar from a storm-intercept vehicle may increase substantially the number of measurements of wind speeds in tornadoes.The radar has recently been modified so that it has frequency modulation (FM) capability, and hence can obtain wind spectra within range bins. A plan is presented for using the radar to find the source of vorticity in tornadoes.

Mortality From a Tornado Outbreak, Alabama, April 27, 2011

PubMed Central

Schnall, Amy H.; Mertzlufft, Caitlin E.; Noe, Rebecca S.; Wolkin, Amy F.; Spears, Jeanne; Casey-Lockyer, Mary; Vagi, Sara J.

2013-01-01

Objectives. We describe the demographics of the decedents from the tornado outbreak in Alabama on April 27, 2011; examine the circumstances of death surrounding these fatalities; and identify measures to prevent future tornado-related fatalities. Methods. We collected information about the decedents from death certificates, disaster-related mortality surveillance, and interview data collected by American Red Cross volunteers from the decedent’s families. We describe demographic characteristics, circumstances and causes of death, and sheltering behaviors before death. Results. Of the 247 fatalities, females and older adults were at highest risk for tornado-related deaths. Most deaths were directly related to the tornadoes, on scene, and trauma-related. The majority of the deceased were indoors in single-family homes. Word of mouth was the most common warning mechanism. Conclusions. This tornado event was the third deadliest in recent US history. Our findings support the need for local community shelters, enhanced messaging to inform the public of shelter locations, and encouragement of word-of-mouth warnings and personal and family preparedness planning, with a special focus on assisting vulnerable individuals in taking shelter. PMID:23763401

Acoustic detection, tracking, and characterization of three tornadoes.

PubMed

Frazier, William Garth; Talmadge, Carrick; Park, Joseph; Waxler, Roger; Assink, Jelle

2014-04-01

Acoustic data recorded at 1000 samples per second by two sensor arrays located at ranges of 1-113 km from three tornadoes that occurred on 24 May 2011 in Oklahoma are analyzed. Accurate bearings to the tornadoes have been obtained using beamforming methods applied to the data at infrasonic frequencies. Beamforming was not viable at audio frequencies, but the data demonstrate the ability to detect significant changes in the shape of the estimated power spectral density in the band encompassing 10 Hz to approximately 100 Hz at distances of practical value from the sensors. This suggests that arrays of more closely spaced sensors might provide better bearing accuracy at practically useful distances from a tornado. Additionally, a mathematical model, based on established relationships of aeroacoustic turbulence, is demonstrated to provide good agreement to the estimated power spectra produced by the tornadoes at different times and distances from the sensors. The results of this analysis indicate that, qualitatively, an inverse relationship appears to exist between the frequency of an observed peak of the power spectral density and the reported tornado intensity.

Mortality from a tornado outbreak, Alabama, April 27, 2011.

PubMed

Chiu, Cindy H; Schnall, Amy H; Mertzlufft, Caitlin E; Noe, Rebecca S; Wolkin, Amy F; Spears, Jeanne; Casey-Lockyer, Mary; Vagi, Sara J

2013-08-01

We describe the demographics of the decedents from the tornado outbreak in Alabama on April 27, 2011; examine the circumstances of death surrounding these fatalities; and identify measures to prevent future tornado-related fatalities. We collected information about the decedents from death certificates, disaster-related mortality surveillance, and interview data collected by American Red Cross volunteers from the decedent's families. We describe demographic characteristics, circumstances and causes of death, and sheltering behaviors before death. Of the 247 fatalities, females and older adults were at highest risk for tornado-related deaths. Most deaths were directly related to the tornadoes, on scene, and trauma-related. The majority of the deceased were indoors in single-family homes. Word of mouth was the most common warning mechanism. This tornado event was the third deadliest in recent US history. Our findings support the need for local community shelters, enhanced messaging to inform the public of shelter locations, and encouragement of word-of-mouth warnings and personal and family preparedness planning, with a special focus on assisting vulnerable individuals in taking shelter.

A Database of Tornado Events as Perceived by the USArray Transportable Array Network

NASA Astrophysics Data System (ADS)

Tytell, J. E.; Vernon, F.; Reyes, J. C.

2015-12-01

Over the course of the deployment of Earthscope's USArray Transportable Array (TA) network there have numerous tornado events that have occurred within the changing footprint of its network. The Array Network Facility based in San Diego, California, has compiled a database of these tornado events based on data provided by the NOAA Storm Prediction Center (SPC). The SPC data itself consists of parameters such as start-end point track data for each event, maximum EF intensities, and maximum track widths. Our database is Antelope driven and combines these data from the SPC with detailed station information from the TA network. We are now able to list all available TA stations during any specific tornado event date and also provide a single calculated "nearest" TA station per individual tornado event. We aim to provide this database as a starting resource for those with an interest in investigating tornado signatures within surface pressure and seismic response data. On a larger scale, the database may be of particular interest to the infrasound research community

Tornado climatology of the contiguous United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ramsdell, J.V.; Andrews, G.L.

1986-05-01

The characteristics of tornadoes that were reported in the contiguous United States for the period from January 1, 1954, through December 31, 1983, have been computed from data in the National Severe Storms Forecast Center tornado data base. The characteristics summarized in this report include frequency and locations of tornadoes, and their lengths, widths, and areas. Tornado strike and intensity probabilities have been estimated on a regional basis, and these estimates have been used to compute wind speeds with 10/sup -5/, 10/sup -6/, and 10/sup -7/ yr/sup -1/ probabilities of occurrence. The 10/sup -7/ yr/sup -1/ wind speeds range frommore » below 200 mph in the western United States to about 330 mph in the vicinity of Kansas and Nebraska. The appendices contain extensive tabulations of tornado statistics. Variations of the characteristics within the contiguous United States are presented in the summaries. Separate tabulations are provided for the contiguous United States, for each state, for each 5/sup 0/ and 1/sup 0/ latitude and longitude box, and for the eastern and western United States.« less

Twitter as a Potential Disaster Risk Reduction Tool. Part II: Descriptive Analysis of Identified Twitter Activity during the 2013 Hattiesburg F4 Tornado.

PubMed

Cooper, Guy Paul; Yeager, Violet; Burkle, Frederick M; Subbarao, Italo

2015-06-29

This article describes a novel triangulation methodological approach for identifying twitter activity of regional active twitter users during the 2013 Hattiesburg EF-4 Tornado. A data extraction and geographically centered filtration approach was utilized to generate Twitter data for 48 hrs pre- and post-Tornado. The data was further validated using six sigma approach utilizing GPS data. The regional analysis revealed a total of 81,441 tweets, 10,646 Twitter users, 27,309 retweets and 2637 tweets with GPS coordinates. Twitter tweet activity increased 5 fold during the response to the Hattiesburg Tornado.  Retweeting activity increased 2.2 fold. Tweets with a hashtag increased 1.4 fold. Twitter was an effective disaster risk reduction tool for the Hattiesburg EF-4 Tornado 2013.

Tornado disaster--Kansas, 1991.

PubMed

1992-03-13

On April 26, 1991, 54 tornadoes swept across six midwestern states, causing 24 deaths and more than 200 injuries, requiring disaster-relief services for more than 8000 persons, and causing property damage of more than $250 million. In Kansas, one tornado, with wind speeds exceeding 260 mph, caused 17 deaths. The 46-mile path of the tornado led through Andover, Kansas (Butler County) (population: 4300), where the town's only outdoor warning siren failed. A mobile-home park (MHP) in Andover with 244 homes and one community storm shelter was struck by the tornado, resulting in the destruction of 205 (84%) of these homes. This report summarizes a poststorm survey, conducted by local health departments, the Kansas Department of Health and Environment, the American Red Cross, and CDC, to identify risk factors for injury and death among persons in the MHP.

Coupling Between Doppler Radar Signatures and Tornado Damage Tracks

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Molthan, Andrew L.; Carey, Lawrence; Carcione, Brian; Smith, Matthew; Schultz, Elise V.; Schultz, Christopher; Lafontaine, Frank

2011-01-01

On April 27, 2011, the southeastern United States was raked with several episodes of severe weather. Numerous tornadoes caused extensive damage, and tragically, the deaths of over 300 people. In Alabama alone, there were 61 confirmed tornados, 4 of them produced EF5 damage, and several were on the ground an hour or more with continuous damage tracks exceeding 80km. The use of Doppler radars covering the region provided reflectivity and velocity signatures that allowed forecasters to monitors the severe storms from beginning to end issuing hundreds of severe weather warnings throughout the day. Meteorologists from the the NWS performed extensive surveys to assess the intensity, duration, and ground track of tornadoes reported during the event. Survey activities included site visits to the affected locations, analysis of radar and satellite data, aerial surveys, and interviews with eyewitnesses. Satellite data from NASA's MODIS and ASTER instruments played a helpful role in determining the location of tornado damage paths and in the assessment. High resolution multispectral and temporal composites helped forecasters corroborate their damage assessments, determine starting and ending points for tornado touchdowns, and helped to provide forecasters with a better big-picture view of the damage region. The imagery also helped to separate damage from the April 27th tornados from severe weather that occurred earlier that month. In a post analysis of the outbreak, tornado damage path signatures observed in the NASA satellite data have been correlated to "debris ball" signatures in the NWS Doppler radars and a special ARMOR dual-polarization radar operated by the University of Alabama Huntsville during the event. The Doppler radar data indicates a circular enhanced reflectivity signal and rotational couplet in the radial velocity likely associated with the tornado that is spatially correlated with the damage tracks in the observed satellite data. An algorithm to detect and isolate the "debris ball" from precipitation signatures in the dual polarization radar data has been developed and verified using the NASA damage track data.

Two Categories of Apparent Tornado-like Prominences

NASA Astrophysics Data System (ADS)

Martin, Sara F.; Venkataramanasastry, Aparna

2014-06-01

Two categories of solar prominences have been described in the literature as having a pattern of mass motions and/or a shape similar to terrestrial tornados. We first identify the two categories associated with prominences in the historic literature and then show that counterparts do exist for both in recent literature but one has not been called a tornado prominence. One category described as being similar to tornados is associated with the barbs of quiescent filaments but barbs appear to have rotational motion only under special conditions. H alpha Doppler observations from Helio Research confirm that this category is an illusion in our mind’s eye resulting from counterstreaming in the large barbs of quiescent filaments. The second category is a special case of rotational motion occurring during the early stages of some erupting prominences, in recent years called the roll effect in erupting prominences. In these cases, the eruption begins with the sideways rolling of the top of a prominence. As the eruption proceeds the rolling motion propagates down one leg or both legs of an erupting prominence depending on whether the eruption is asymmetric or symmetric respectively. As an asymmetric eruption proceeds, the longer lasting leg becomes nearly vertical and has true rotational motion. If only this phase of the eruption was observed, as in the historic cases, it was called a tornado prominence and spectra recorded in these cases provide proof of the rotational motion. When one observes an entire eruption which exhibits the rolling motion, as accomplished at Helio Research, the similarity to a tornado is lost because the event as a whole has quite a different nature and the analogy to a terrestrial tornado not longer appears suitable or helpful in understanding the observed and deduced physical processes. Our conclusion is that there are no solar prominences with motions that are usefully described as tornado or tornado-like events aside from the fun of observing some prominence barbs whose mass motions yield a fascinating illusion of rotational motion under special conditions.

Great Bend tornadoes of August 30, 1974

NASA Technical Reports Server (NTRS)

Umenhofer, T. A.; Fujita, T. T.; Dundas, R.

1977-01-01

Photogrammetric analyses of movies and still pictures taken of the Great Bend, Kansas Tornado series have been used to develop design specifications for nuclear power plants and facilities. A maximum tangential velocity of 57 m/sec and a maximum vertical velocity of 27 m/sec are determined for one suction vortex having a translational velocity of 32 m/sec. Three suction vortices with radii in the 20 to 30 m range are noted in the flow field of one tornado; these suction vortices apparently form a local convergence of inflow air inside the outer portion of the tornado core.

The political ecology of disaster: an analysis of factors influencing U.S. tornado fatalities and injuries, 1998-2000.

PubMed

Donner, William R

2007-08-01

This study examines casualties from tornadoes in the United States between the years 1998 and 2000. A political model of human ecology (POET) was used to explore how the environment, technology, and social inequality influence rates of fatalities and injuries in two models. Data were drawn from four sources: John Hart's Severe Plot v2.0, National Weather Service (NWS) Warning Verification data, Storm Prediction Center (SPC) watch data, and tract-level census data. Negative binomial regression was used to analyze the causes of tornado fatalities and injuries. Independent variables (following POET) are classified in the following manner: population, organization, environment, and technology. Rural population, population density, and household size correspond to population; racial minorities and deprivation represent social organization; tornado area represents environment; and tornado watches and warnings, as well as mobile homes, correspond to technology. Findings suggest a strong relationship between the size of a tornado path and both fatalities and injuries, whereas other measures related to technology, population, and organization produce significant yet mixed results. Census tracts having larger populations of rural residents was, of the nonenvironmental factors, the most conclusive regarding its effects across the two models. The outcomes of analysis, although not entirely supportive of the model presented in this study, suggest to some degree that demographic and social factors play a role in vulnerability to tornadoes.

Apparent Solar Tornado-Like Prominences

NASA Astrophysics Data System (ADS)

Panasenco, Olga; Martin, Sara F.; Velli, Marco

2014-02-01

Recent high-resolution observations from the Solar Dynamics Observatory (SDO) have reawakened interest in the old and fascinating phenomenon of solar tornado-like prominences. This class of prominences was first introduced by Pettit ( Astrophys. J. 76, 9, 1932), who studied them over many years. Observations of tornado prominences similar to the ones seen by SDO had already been documented by Secchi ( Le Soleil, 1877). High-resolution and high-cadence multiwavelength data obtained by SDO reveal that the tornado-like appearance of these prominences is mainly an illusion due to projection effects. We discuss two different cases where prominences on the limb might appear to have a tornado-like behavior. One case of apparent vortical motions in prominence spines and barbs arises from the (mostly) 2D counterstreaming plasma motion along the prominence spine and barbs together with oscillations along individual threads. The other case of apparent rotational motion is observed in a prominence cavity and results from the 3D plasma motion along the writhed magnetic fields inside and along the prominence cavity as seen projected on the limb. Thus, the "tornado" impression results either from counterstreaming and oscillations or from the projection on the plane of the sky of plasma motion along magnetic-field lines, rather than from a true vortical motion around an (apparent) vertical or horizontal axis. We discuss the link between tornado-like prominences, filament barbs, and photospheric vortices at their base.

Black Swan Event Assessment for Fort Leonard Wood, Missouri

DTIC Science & Technology

2016-03-01

FEMA standards category and using ASCE 7-05. (Source: FEMA.) ................ 16 Figure 9. Estimated trajectory and impact area of the Joplin tornado in...Missouri on May 22, 2011. (Source: U.S. Army Corps of Engineers, Kansas City District.) .............. 18 Figure 10. Tornado intensities and path...near Fort Leonard Wood, Missouri. (Source: Tornado History Project webpage

Natural Disaster: Long-Range Impact on Human Response to Future Disaster Threats.

ERIC Educational Resources Information Center

Hanson, Susan; And Others

1979-01-01

The study examines the effect of a prior tornado disaster occurring in a community and that community's current response to a tornado threat. The study concludes that it is not past experience with tornadoes that relates to response to warnings, but rather awareness. Experience is but one source of information contributing to their awareness. (RE)

Round and Round

ERIC Educational Resources Information Center

Damonte, Kathleen

2004-01-01

A tornado is a rotating, funnel-shaped column of air, which extends from a thunderstorm to the ground. The winds of a tornado can reach up to 480 km per hour. This is about five times faster than a car driving on a highway. Tornadoes can be almost invisible until they pick up dust and debris. This article describes an activity that stimulates…

Structure and Prevalence of PTSD Symptomology in Children Who Have Experienced a Severe Tornado

ERIC Educational Resources Information Center

Evans, Linda Garner; Oehler-Stinnett, Judy

2006-01-01

Children served by school psychologists are frequently impacted by natural disasters. In the United States, tornadoes are a particular threat but have been studied very little. The current investigation developed a scale for assessing posttraumatic stress disorder (PTSD) in children in Kindergarten to Grade 6 impacted by a severe tornado. Six…

Teacher Guidelines for Helping Students after a Tornado

ERIC Educational Resources Information Center

National Child Traumatic Stress Network, 2013

2013-01-01

Being in a tornado can be very frightening, and the days, weeks, and months following the storm can be very stressful. Most families recover over time, especially with the support of relatives, friends, and their community. But different families may have different experiences during and after a tornado, and how long it takes them to recover will…

Apophysomyces trapeziformis infection associated with a tornado-related injury.

PubMed

Weddle, Gina; Gandy, Kimberly; Bratcher, Denise; Pahud, Barbara; Jackson, Mary Anne

2012-06-01

This report defines the role of Apophysomyces as an aggressive fungal pathogen seen after a tornado injury. Clinical and laboratory manifestations of infections after environmentally contaminated wounds incurred during a tornado are outlined, emphasizing mechanism of injury, comorbidities, and diagnostic and treatment challenges. Therapy with systemic antifungal therapy and aggressive serial tissue debridement was successful in achieving cure.

78 FR 72641 - Request for Public Comments on Draft Final Report on the Technical Investigation of the May 22...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-03

..., 2011 Tornado in Joplin, Missouri AGENCY: National Institute of Standards and Technology, United States... for public comment of the draft final report of the investigation conducted by NIST into the tornado... found on the Joplin Investigation Web page http://www.nist.gov/el/disasterstudies/weather/joplin_tornado...

Tornado Protection: Selecting and Designing Safe Areas in Buildings.

ERIC Educational Resources Information Center

Abernethy, James J.

Tornadoes and extreme winds cause heavy loss of life and property damage throughout the United States. Most buildings offer significant protection from this danger, and building administrators should know the areas where this protection is available. This booklet presents a review of three schools, all of which were struck by tornadoes on April 3,…

A Study of Emergency Management Policy Regarding the Use of Tornado Sirens during Severe Weather in the State of Missouri

NASA Astrophysics Data System (ADS)

Ebner, Nicholas William

In recent years there have been many devastating tornadoes which have hit cities of all sizes across the state of Missouri, including St. Louis (April 22, 2011) rated EF 4, Joplin (May 22, 2011) rated EF 5 and Sedalia (May 25, 2011) rated EF-2. These, along with other catastrophic tornadoes in cities such as Tuscaloosa and Birmingham, Alabama, have increased the conversation regarding public policy of the use of tornado sirens. In many Missouri counties, guidelines and procedures regarding when to warn the public are inconsistent. After the media, emergency management directors and tornado sirens are the largest source and fastest way of informing the public of impending severe weather with the capability of producing tornadoes. With inconsistencies from county to county in Missouri and a lack of oversight by the state, uncertain and unregulated policies can cause citizens to be confused as to the specific meaning of these sirens. These variations in policy can range from who has responsibility over siren activation to the circumstances in which sirens are sounded. Frequently, in these time-sensitive situations, emergency managers do not have the sole responsibility of when to sound sirens. This decision is often left up to an assortment of individuals such as the police or fire department. It is well documented that citizens have become desensitized to tornado sirens based on the frequent number of soundings that have proven either to be a false alarm or siren activation provoked by other non-tornadic weather events. This occurs because many counties use their tornado sirens for reasons other than to alert citizens specifically of the immediate threat of tornadoes. Using a survey and archival research to gather information such as the jurisdiction policies on who activates sirens and the activation guidelines, a better understanding of how the warning process throughout Missouri was achieved. Suggestions are made that can be used by Emergency Management Directors (EMDs) when siren activation may be necessary. The goal is to use this research to assist the development of statewide guidelines on appropriate activation of tornado sirens during severe weather events. If the suggested policies are considered by EMDs, it is hopeful a unified policy throughout the state can be developed. Thus, the desensitization of the public to sirens can be reduced and allow for the effective use of tornado sirens in warning the public.

Using Satellite Imagery to Identify Tornado Damage Tracks and Recovery from the April 27, 2011 Severe Weather Outbreak

NASA Technical Reports Server (NTRS)

Molthan, Andrew L.; Cole, Tony A.; Burks, Jason E.; Bell, Jordan R.

2014-01-01

Emergency response to natural disasters requires coordination between multiple local, state, and federal agencies. Single, relatively weak tornado events may require comparatively simple response efforts; but larger "outbreak" events with multiple strong, long-track tornadoes can benefit from additional tools to help expedite these efforts. Meteorologists from NOAA's National Weather Service conduct field surveys to map tornado tracks, assess damage, and determine the tornado intensity following each event. Moderate and high resolution satellite imagery can support these surveys by providing a high-level view of the affected areas. Satellite imagery could then be used to target areas for immediate survey or to corroborate the results of the survey after it is completed. In this study, the feasibility of using satellite imagery to identify tornado damage tracks was determined by comparing the characteristics of tracks observed from low-earth orbit to tracks assessed during the official NWS storm survey process. Of the 68 NWS confirmed centerlines, 24 tracks (35.3%) could be distinguished from other surface features using satellite imagery. Within each EF category, 0% of EF-0, 3% of EF-1, 50% of EF-2, 77.7% of EF-3, 87.5% of EF-4 and 100% of EF-5 tornadoes were detected. It was shown that satellite data can be used to identify tornado damage tracks in MODIS and ASTER NDVI imagery, where damage to vegetation creates a sharp drop in values though the minimum EF-category which can be detected is dependent upon the type of sensor used and underlying vegetation. Near-real time data from moderate resolution sensors compare favorably to field surveys after the event and suggest that the data can provide some value in the assessment process.

Injuries and post-traumatic stress following historic tornados: Alabama, April 2011.

PubMed

Niederkrotenthaler, Thomas; Parker, Erin M; Ovalle, Fernando; Noe, Rebecca S; Noe, Rebecca E; Bell, Jeneita; Xu, Likang; Morrison, Melissa A; Mertzlufft, Caitlin E; Sugerman, David E

2013-01-01

We analyzed tornado-related injuries seen at hospitals and risk factors for tornado injury, and screened for post-traumatic stress following a statewide tornado-emergency in Alabama in April 2011. We conducted a chart abstraction of 1,398 patients at 39 hospitals, mapped injured cases, and conducted a case-control telephone survey of 98 injured cases along with 200 uninjured controls. Most (n = 1,111, 79.5%) injuries treated were non-life threatening (Injury Severity Score ≤ 15). Severe injuries often affected head (72.9%) and chest regions (86.4%). Mobile home residents showed the highest odds of injury (OR, 6.98; 95% CI: 2.10-23.20). No severe injuries occurred in tornado shelters. Within permanent homes, the odds of injury were decreased for basements (OR, 0.13; 95% CI: 0.04-0.40), bathrooms (OR, 0.22; 95% CI: 0.06-0.78), hallways (OR, 0.31; 95% CI: 0.11-0.90) and closets (OR, 0.25; 95% CI: 0.07-0.80). Exposure to warnings via the Internet (aOR, 0.20; 95% CI: 0.09-0.49), television (aOR, 0.45; 95% CI: 0.24-0.83), and sirens (aOR, 0.50; 95% CI: 0.30-0.85) decreased the odds of injury, and residents frequently exposed to tornado sirens had lower odds of injury. The prevalence of PTSD in respondents was 22.1% and screening positive for PTSD symptoms was associated with tornado-related loss events. Primary prevention, particularly improved shelter access, and media warnings, seem essential to prevent severe tornado-injury. Small rooms such as bathrooms may provide some protection within permanent homes when no underground shelter is available.

Injuries and Post-Traumatic Stress following Historic Tornados: Alabama, April 2011

PubMed Central

Niederkrotenthaler, Thomas; Parker, Erin M.; Ovalle, Fernando; Noe, Rebecca E.; Bell, Jeneita; Xu, Likang; Morrison, Melissa A.; Mertzlufft, Caitlin E.; Sugerman, David E.

2013-01-01

Objectives We analyzed tornado-related injuries seen at hospitals and risk factors for tornado injury, and screened for post-traumatic stress following a statewide tornado-emergency in Alabama in April 2011. Methods We conducted a chart abstraction of 1,398 patients at 39 hospitals, mapped injured cases, and conducted a case-control telephone survey of 98 injured cases along with 200 uninjured controls. Results Most (n = 1,111, 79.5%) injuries treated were non-life threatening (Injury Severity Score ≤15). Severe injuries often affected head (72.9%) and chest regions (86.4%). Mobile home residents showed the highest odds of injury (OR, 6.98; 95% CI: 2.10–23.20). No severe injuries occurred in tornado shelters. Within permanent homes, the odds of injury were decreased for basements (OR, 0.13; 95% CI: 0.04–0.40), bathrooms (OR, 0.22; 95% CI: 0.06–0.78), hallways (OR, 0.31; 95% CI: 0.11–0.90) and closets (OR, 0.25; 95% CI: 0.07–0.80). Exposure to warnings via the Internet (aOR, 0.20; 95% CI: 0.09–0.49), television (aOR, 0.45; 95% CI: 0.24–0.83), and sirens (aOR, 0.50; 95% CI: 0.30–0.85) decreased the odds of injury, and residents frequently exposed to tornado sirens had lower odds of injury. The prevalence of PTSD in respondents was 22.1% and screening positive for PTSD symptoms was associated with tornado-related loss events. Conclusions Primary prevention, particularly improved shelter access, and media warnings, seem essential to prevent severe tornado-injury. Small rooms such as bathrooms may provide some protection within permanent homes when no underground shelter is available. PMID:24367581

Ground beetle (Coleoptera, Carabidae) assemblages inhabiting Scots pine stands of Puszcza Piska Forest: six-year responses to a tornado impact.

PubMed

Skłodowski, Jarosław; Garbalińska, Paulina

2011-01-01

Ground beetle assemblages were studied during 2003-08 in the Pisz Forest by comparing stands disturbed by a tornado to undisturbed control stands. The following exploratory questions were put forward. (1) How do the carabid assemblages change during six years following the tornado impact? (2) Does the carabid assemblage recovery begin during the six first post-tornado years? To assess the state of carabid assemblages we used two indices: the MIB (Mean Individual Biomass) and the SPC (Sum of Progressive Characteristics). Carabid assemblages in the disturbed and in the control stands, as expressed by these two indices, were compared using the length of a regression distance (sample distance in a MIB:SPC coordinate system). A cluster analysis revealed that the assemblages of the disturbed and the control stands were different. The tornado-impacted stands produced lower carabid catch rates, but species richness was significantly higher there than in the control stands. They hosted lower proportions of individuals of European species, of large zoophages, and of forest and brachypterous species, than the control stands. The observed reduction in SPC and MIB, and an increase in the regression distances may indicate that the carabid assemblages had not started to recover from the tornado-caused disturbance. Carabid assemblages apparently responded to the tornado in two steps. Firstly, the first three years were characterized by moderate decreases of index values. Secondly, from the fourth to the sixth year after the tornado, many observed changes became magnified. We did not observe clear signals of the recovery of forest carabid assemblages during the six follow-up years.

Ground beetle (Coleoptera, Carabidae) assemblages inhabiting Scots pine stands of Puszcza Piska Forest: six-year responses to a tornado impact

PubMed Central

Skłodowski, Jarosław; Garbalińska, Paulina

2011-01-01

Abstract Ground beetle assemblages were studied during 2003-08 in the Pisz Forest by comparing stands disturbed by a tornado to undisturbed control stands. The following exploratory questions were put forward. (1) How do the carabid assemblages change during six years following the tornado impact? (2) Does the carabid assemblage recovery begin during the six first post-tornado years? To assess the state of carabid assemblages we used two indices: the MIB (Mean Individual Biomass) and the SPC (Sum of Progressive Characteristics). Carabid assemblages in the disturbed and in the control stands, as expressed by these two indices, were compared using the length of a regression distance (sample distance in a MIB:SPC coordinate system). A cluster analysis revealed that the assemblages of the disturbed and the control stands were different. The tornado-impacted stands produced lower carabid catch rates, but species richness was significantly higher there than in the control stands. They hosted lower proportions of individuals of European species, of large zoophages, and of forest and brachypterous species, than the control stands. The observed reduction in SPC and MIB, and an increase in the regression distances may indicate that the carabid assemblages had not started to recover from the tornado-caused disturbance. Carabid assemblages apparently responded to the tornado in two steps. Firstly, the first three years were characterized by moderate decreases of index values. Secondly, from the fourth to the sixth year after the tornado, many observed changes became magnified. We did not observe clear signals of the recovery of forest carabid assemblages during the six follow-up years. PMID:21738422

Fallout of Debris from Tornadic Thunderstorms: A Historical Perspective and Two Examples from VORTEX.

NASA Astrophysics Data System (ADS)

Snow, John T.; Wyatt, Amy Lee; McCarthy, Ann K.; Bishop, Eric K.

1995-10-01

Preliminary results of an investigation of debris lofted by tornadoes, its long-distance transport by thunderstorms, and its subsequent fallout are reported. The authors begin with a review of historical accounts, including the unique study of the 1984 Barneveld, Wisconsin, tornado by Anderson, which shows that long-distance transport and fallout of debris have occurred and that distances involved have been significant. The authors then report first-hand evidence of these phenomena in two events with F2 tornadoes: the Tuskahoma, Oklahorna, tornado of 25 April 1994 and the Gainesville, Texas, tornadoes of 26 April 1994. In both cases, traceable material in the form of canceled checks, bills-of-sale, invoices, and legal documents were reported to the authors, who were able to locate the source locations for several of these items. The authors close with some conjectures on the implications of these first findings.

Toward better assessment of tornado potential in typhoons: Significance of considering entrainment effects for CAPE

NASA Astrophysics Data System (ADS)

Sueki, Kenta; Niino, Hiroshi

2016-12-01

The characteristics of typhoons that spawned tornadoes (tornadic typhoons: TTs) in Japan from 1991 to 2013 were investigated by composite analysis using the Japanese 55 year Reanalysis and compared with those of typhoons that did not spawn tornadoes (nontornadic typhoons: NTs). We found that convective available potential energy (CAPE), which considers the effects of entrainment (entraining CAPE: E-CAPE), and storm-relative environmental helicity (SREH) are significantly large in the northeast quadrant of TTs where tornadoes frequently occur and that E-CAPE and SREH in that quadrant for TTs are larger than those for NTs. On the other hand, ordinary CAPE without entrainment does not account for the spatial distribution of tornado occurrences nor does it distinguish TTs from NTs. E-CAPE is sensitive to humidity in the midtroposphere; thus, it is effective for detecting a conditionally unstable layer up to about 550 hPa, which is distinctive of TTs.

The Teton-Yellowstone Tornado of 21 July 1987

NASA Technical Reports Server (NTRS)

Fujita, T. Theodore

1989-01-01

The Teton-Yellowstone Tornado, rated F4, crossed the Continental Divide at 3070 m, leaving behind a damage swath 39.2-km long and 2.5-km wide. A detailed damage analysis by using stereo-pair and color photos revealed the existence of four spinup swirl marks and 72 microburst outflows inside the damage area. The tornado was spawned by a mesocyclone that formed at the intersection of a mesohigh boundary and a warm front. The parent cloud of the tornado, tracked on eight infrared-temperature maps from GOES East and West, moved at 25 m s-1 and the number of cold temperature pixels below -60 C reached a distinct peak during the tornado time. Identified and tracked also are two warm spots enclosed inside the cold anvil cloud. On the basis of their identity and movement, an attempt was made to explain the cause of these spots as being the stratospheric cirrus clouds.

Role of electric discharges in the generation of atmospheric vortices

NASA Astrophysics Data System (ADS)

Sinkevich, O. A.; Maslov, S. A.; Gusein-zade, N. G.

2017-02-01

The existing thermohydrodynamic and hydroelectromagnetic models of tornado are considered. The potentialities of the humid atmosphere as a heat engine generating air vortices are analyzed in detail. The ability of long-term atmospheric electric discharges to form a tornado funnel and create an initial twist of up to 10-3-10-2 s-1 in it are estimated. The possible effect of a lightning discharge on the initiation and evolution of the tornado is discussed. It is shown that the electric current flowing along the lightning channel can lead to helical instability and generation of a weak primary vortex. The channel formed in the atmosphere by a lightning discharge and the vortex motion of the parent thundercloud can enhance the primary vortex and promote its transformation into a tornado. Possible mechanisms of enhancement of the primary vortex created by a lightning discharge and the possibility of its transformation into a tornado in the postdischarge stage are discussed.

Violent tornado climatography, 1880-1982

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grazulis, T.P.

1984-05-01

All known information sources, ranging from newspaper reports to the University of Chicago (DAPPL) and National Oceanic and Atmospheric Administration (NOAA/NSSFC) data lists, were utilized to produce a self-consistent compilation and description of violent tornado occurrences in the contiguous United States for the years 1880 through 1982. The 969 F-scale 4 and 5 tornadoes comprise the most complete and rational data base available for studies elated to violent tornado risk assessment; the data provide improved bases for licensing decisions and development of standards in safety at nuclear facility sites. Reconciliation of the DAPPL and NSSFC data lists for violent tornadoesmore » has been achieved. Analysis of the data shows geographical and temporal variability of tornado occurrences; suggestions are given to help account for nonuniform distributions, and other suggestions are made for needed future research. 32 references, 14 figures, 8 tables.« less

Twitter as a Potential Disaster Risk Reduction Tool. Part II: Descriptive Analysis of Identified Twitter Activity during the 2013 Hattiesburg F4 Tornado

PubMed Central

Cooper, Guy Paul; Yeager, Violet; Burkle, Frederick M.; Subbarao, Italo

2015-01-01

Background: This article describes a novel triangulation methodological approach for identifying twitter activity of regional active twitter users during the 2013 Hattiesburg EF-4 Tornado. Methodology: A data extraction and geographically centered filtration approach was utilized to generate Twitter data for 48 hrs pre- and post-Tornado. The data was further validated using six sigma approach utilizing GPS data. Results: The regional analysis revealed a total of 81,441 tweets, 10,646 Twitter users, 27,309 retweets and 2637 tweets with GPS coordinates. Conclusions: Twitter tweet activity increased 5 fold during the response to the Hattiesburg Tornado.  Retweeting activity increased 2.2 fold. Tweets with a hashtag increased 1.4 fold. Twitter was an effective disaster risk reduction tool for the Hattiesburg EF-4 Tornado 2013.  PMID:26203396

76 FR 42683 - Establishment of a Team Under the National Construction Safety Team Act

Federal Register 2010, 2011, 2012, 2013, 2014

2011-07-19

... Safety Team Act. The Team was established to study the effects of the tornado that touched down in Joplin... reconnaissance team to collect information and data related to the tornado that touched down in Joplin, MO, on... the effects of the tornado that touched down in Joplin, MO, on May 22. The NIST Director will appoint...

Prepare to protect: Operating and maintaining a tornado safe room.

PubMed

Herseth, Andrew; Goldsmith-Grinspoon, Jennifer; Scott, Pataya

2017-06-01

Operating and maintaining a tornado safe room can be critical to the effective continuity of business operations because a firm's most valuable asset is its people. This paper describes aspects of operations and maintenance (O&M) for existing tornado safe rooms as well as a few planning and design aspects that affect the ultimate operation of a safe room for situations where a safe room is planned, but not yet constructed. The information is based on several Federal Emergency Management Agency safe room publications that provide guidance on emergency management and operations, as well as the design and construction of tornado safe rooms.

A simple hydrodynamic model of tornado-like vortices

NASA Astrophysics Data System (ADS)

Kurgansky, M. V.

2015-05-01

Based on similarity arguments, a simple fluid dynamic model of tornado-like vortices is offered that, with account for "vortex breakdown" at a certain height above the ground, relates the maximal azimuthal velocity in the vortex, reachable near the ground surface, to the convective available potential energy (CAPE) stored in the environmental atmosphere under pre-tornado conditions. The relative proportion of the helicity (kinetic energy) destruction (dissipation) in the "vortex breakdown" zone and, accordingly, within the surface boundary layer beneath the vortex is evaluated. These considerations form the basis of the dynamic-statistical analysis of the relationship between the tornado intensity and the CAPE budget in the surrounding atmosphere.

Alabama Disasters: Leveraging NASA EOS to Explore the Environmental and Economic Impact of the April 27 Tornado Outbreak

NASA Technical Reports Server (NTRS)

Herdy, Claire; Luvall, Jeff

2012-01-01

The disastrous tornado outbreak in Alabama on April 27, 2011 greatly impacted the economy of the state. On record, the tornado outbreak was the second deadliest tornado outbreak in U.S. When considering the agricultural and value-added activities such as food and timber processing, farm inputs, manufacturing, transportation, and retail sales, the dollar value of Alabama agribusiness annually exceeds $40 billion (NASS, 2011). This research aims to examine how the timber and agriculture damage affected the state economy of Alabama and will be used to aid in long-term economic recovery. ASTER imagery was used along with ground-truthed NASS (National Agriculture Statistics Service) crop location records to verify the economic impact tornadoes had on the agricultural economy of the state. This swath damage can be calculated by correlating tornado path with NASS statistics on crop yield, precisely showing the fields affected and dollars lost to this disaster. Not only can this be executed manually using ENVI and ArcGIS, but also through the use of Python, a programming language that has the ability to automate the process, creating a product for initial damage assessment.

Investigating Mesoscale Convective Systems and their Predictability Using Machine Learning

NASA Astrophysics Data System (ADS)

Daher, H.; Duffy, D.; Bowen, M. K.

2016-12-01

A mesoscale convective system (MCS) is a thunderstorm region that lasts several hours long and forms near weather fronts and can often develop into tornadoes. Here we seek to answer the question of whether these tornadoes are "predictable" by looking for a defining characteristic(s) separating MCSs that evolve into tornadoes versus those that do not. Using NASA's Modern Era Retrospective-analysis for Research and Applications 2 reanalysis data (M2R12K), we apply several state of the art machine learning techniques to investigate this question. The spatial region examined in this experiment is Tornado Alley in the United States over the peak tornado months. A database containing select variables from M2R12K is created using PostgreSQL. This database is then analyzed using machine learning methods such as Symbolic Aggregate approXimation (SAX) and DBSCAN (an unsupervised density-based data clustering algorithm). The incentive behind using these methods is to mathematically define a MCS so that association rule mining techniques can be used to uncover some sort of signal or teleconnection that will help us forecast which MCSs will result in tornadoes and therefore give society more time to prepare and in turn reduce casualties and destruction.

Examining Rotational Ground Motion Induced by Tornados

NASA Astrophysics Data System (ADS)

Kessler, Elijah; Dunn, Robert

2016-03-01

Ring lasers are well known for their ability to detect rotation and to serve as replacements for mechanical gyroscopes. The sensitivity of large ring lasers to various forms of ground motion is less familiar. Since ring lasers preferentially measure rotational ground motion and a standard seismograph is designed to measure translational and vertical ground motion, each device responds to different aspects of ground movement. Therefore, the two instruments will be used to explore responses to microseisms, earthquake generated shear waves, and in particular tornado generated ground movement. On April 27, 2014 an EF4 tornado devastated Vilonia, AR a small town ~ 21 km from the Hendrix College ring laser. The proximity of the tornado's path to the ring laser interferometer and to a seismograph located in Vilonia provided the opportunity to examine the response of these instruments to tornadic generated ground motion. Our measurements suggest tornadic weather systems can produce both rotational and lateral ground motion. This contention is supported by an after the fact damage survey which found that the tornado flattened a forest in which trees were uprooted and laid down in a pair of converging arcs with the centerline pointed in the direction of the tornado's path.

Exploring links between biomass burning smoke and tornado likelihood: From regional to large-eddy scale simulations

NASA Astrophysics Data System (ADS)

Saide, P. E.; Thompson, G.; Eidhammer, T.; da Silva, A. M., Jr.; Pierce, R. B.; Carmichael, G. R.

2015-12-01

Biomass burning smoke from Central America can have the potential to enhance the likelihood of tornado occurrence and intensity in the SE US by changing the environment where tornadic storms form (Saide et al., GRL 2015). In this presentation we build over this study to further our understanding of these interactions on multiple dimensions: 1) Biomass burning smoke emissions are constrained using an inverse modeling technique to improve the representation of smoke loads and its impacts, 2) The representation of these smoke-tornado interactions are assessed when using a simplified aerosol scheme with the intent of introducing these feedbacks into numerical weather prediction in the future, 3) The occurrence of these interactions is investigated for other tornado outbreaks on the record to learn about their frequency and under what conditions they occur, and 4) Multi-scale simulations are performed from regional to tornado-resolving scales to assess the impact of smoke on the number of tornadoes formed and their EF intensity. Future steps will also be discussed. The image below shows MODIS-Aqua satellite products for 27 April 2011 over the southeast US, Central America and the Gulf of Mexico (GoM), along with tornado tracks (red solid lines, thickness indicates the magnitude of the tornado reports , thickest=5, thinnest=1) for the period from April 26-28. The background is a true color image of the surface, clouds, and smoke, with yellow markers indicating fire detections and an iridescent overlay showing aerosol optical depth (AOD). Red, green and purple colors show high (1.0), medium (0.6) and low (0.1) AOD values. The article by Saide et al. (2015) shows that the increase in aerosol loads in the GoM is produced by fires in Central America, and this smoke is further transported to the southeast US where it can interact with clouds and radiation producing environmental conditions more favorable to significant tornado occurrence for the historical outbreak on 27 April 2011. Satellite true color image, AOD, and fire detection retrievals obtained from the NASA Level 1 and Atmosphere Archive and Distribution System (LAADS); Tornado reports obtained from the NOAA Storm Prediction Center; imagery courtesy of Brad Pierce NOAA Satellite and Information Service (NESDIS) Center for Satellite Applications and Research (STAR).

Are Tornadoes Getting Stronger?

NASA Astrophysics Data System (ADS)

Elsner, J.; Jagger, T.

2013-12-01

A cumulative logistic model for tornado damage category is developed and examined. Damage path length and width are significantly correlated to the odds of a tornado receiving the next highest damage category. Given values for the cube root of path length and square root of path width, the model predicts a probability for each category. The length and width coefficients are insensitive to the switch to the Enhanced Fujita (EF) scale and to distance from nearest city although these variables are statistically significant in the model. The width coefficient is sensitive to whether or not the tornado caused at least one fatality. This is likely due to the fact that the dimensions and characteristics of the damage path for such events are always based on ground surveys. The model predicted probabilities across the categories are then multiplied by the center wind speed from the categorical EF scale to obtain an estimate of the highest tornado wind speed on a continuous scale in units of meters per second. The estimated wind speeds correlate at a level of .82 (.46, .95) [95% confidence interval] to wind speeds estimated independently from a doppler radar calibration. The estimated wind speeds allow analyses to be done on the tornado database that are not possible with the categorical scale. The modeled intensities can be used in climatology and in environmental and engineering applications. More work needs to be done to understand the upward trends in path length and width. The increases lead to an apparent increase in tornado intensity across all EF categories.

Explicating Experience: Development of a Valid Scale of Past Hazard Experience for Tornadoes.

PubMed

Demuth, Julie L

2018-03-23

People's past experiences with a hazard theoretically influence how they approach future risks. Yet, past hazard experience has been conceptualized and measured in wide-ranging, often simplistic, ways, resulting in mixed findings about its relationship with risk perception. This study develops a scale of past hazard experiences, in the context of tornadoes, that is content and construct valid. A conceptual definition was developed, a set of items were created to measure one's most memorable and multiple tornado experiences, and the measures were evaluated through two surveys of the public who reside in tornado-prone areas. Four dimensions emerged of people's most memorable experience, reflecting their awareness of the tornado risk that day, their personalization of the risk, the intrusive impacts on them personally, and impacts experienced vicariously through others. Two dimensions emerged of people's multiple experiences, reflecting common types of communication received and negative emotional responses. These six dimensions are novel in that they capture people's experience across the timeline of a hazard as well as intangible experiences that are both direct and indirect. The six tornado experience dimensions were correlated with tornado risk perceptions measured as cognitive-affective and as perceived probability of consequences. The varied experience-risk perception results suggest that it is important to understand the nuances of these concepts and their relationships. This study provides a foundation for future work to continue explicating past hazard experience, across different risk contexts, and for understanding its effect on risk assessment and responses. © 2018 Society for Risk Analysis.

Family emergency preparedness plans in severe tornadoes.

PubMed

Cong, Zhen; Liang, Daan; Luo, Jianjun

2014-01-01

Tornadoes, with warnings usually issued just minutes before their touchdowns, pose great threats to properties and people's physical and mental health. Few studies have empirically investigated the association of family emergency preparedness planning and observed protective behaviors in the context of tornadoes. The purpose of this study was to examine predictors for the action of taking shelter at the time of tornadoes. Specifically, this study investigated whether having a family emergency preparedness plan was associated with higher likelihood of taking shelter upon receiving tornado warnings. This study also examined the effects of socioeconomic status and functional limitations on taking such actions. A telephone survey based on random sampling was conducted in 2012 with residents in Tuscaloosa AL and Joplin MO. Each city experienced considerable damages, injuries, and casualties after severe tornadoes (EF-4 and EF-5) in 2011. The working sample included 892 respondents. Analysis was conducted in early 2013. Logistic regression identified emergency preparedness planning as the only shared factor that increased the likelihood of taking shelter in both cities and the only significant factor in Joplin. In Tuscaloosa, being female and white also increased the likelihood of taking shelter. Disability was not found to have an effect. This study provided empirical evidence on the importance of having a family emergency preparedness plan in mitigating the risk of tornadoes. The findings could be applied to other rapid-onset disasters. © 2013 American Journal of Preventive Medicine Published by American Journal of Preventive Medicine All rights reserved.

The Tornado Hazard in Southern New England: History, Characteristics, Student and Teacher Perceptions

ERIC Educational Resources Information Center

Lewis, Thomas R.

2006-01-01

People generally do not perceive New England to be tornado-prone. Yet, there is a long history of such storms in the six states going back to the late seventeenth century. Usually, New England tornadoes are small and short-lived; even so, some have caused many deaths and much property damage. There is a greater probability for a person to be…

Risk Communication and Public Education in Edmonton, Alberta, Canada on the 10th Anniversary of the "Black Friday" Tornado

ERIC Educational Resources Information Center

Blanchard-Boehm, R. Denise; Cook, M. Jeffrey

2004-01-01

In July 1997, on the 10th anniversary of the great "Black Friday" Tornado, city officials of Edmonton, the print and broadcast media, agencies dealing in emergency management, and the national weather organisation recounted stories of the 1987, F5 tornado that struck Edmonton on a holiday weekend. The information campaign also presented…

Residential tornado safe room from commodity wood products – impact and wind pressure testing

Treesearch

Robert H. Falk; James J. Bridwell; C. Adam Senalik; Marshall Begel

2018-01-01

A tornado safe room is a shelter designed to provide protection during a tornado and is specifically engineered to resist the high wind pressures and debris impact generated by these high wind events. The required performance criteria of these shelters has been established and is found in the International Code Council Standard for the Design and Construction of Storm...

A solar tornado observed by EIS. Plasma diagnostics

NASA Astrophysics Data System (ADS)

Levens, P. J.; Labrosse, N.; Fletcher, L.; Schmieder, B.

2015-10-01

Context. The term "solar tornadoes" has been used to describe apparently rotating magnetic structures above the solar limb, as seen in high resolution images and movies from the Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory (SDO). These often form part of the larger magnetic structure of a prominence, however the links between them remain unclear. Here we present plasma diagnostics on a tornado-like structure and its surroundings, seen above the limb by the Extreme-ultraviolet Imaging Spectrometer (EIS) aboard the Hinode satellite. Aims: We aim to extend our view of the velocity patterns seen in tornado-like structures with EIS to a wider range of temperatures and to use density diagnostics, non-thermal line widths, and differential emission measures to provide insight into the physical characteristics of the plasma. Methods: Using Gaussian fitting to fit and de-blend the spectral lines seen by EIS, we calculated line-of-sight velocities and non-thermal line widths. Along with information from the CHIANTI database, we used line intensity ratios to calculate electron densities at each pixel. Using a regularised inversion code we also calculated the differential emission measure (DEM) at different locations in the prominence. Results: The split Doppler-shift pattern is found to be visible down to a temperature of around log T = 6.0. At temperatures lower than this, the pattern is unclear in this data set. We obtain an electron density of log ne = 8.5 when looking towards the centre of the tornado structure at a plasma temperature of log T = 6.2, as compared to the surroundings of the tornado structure where we find log ne to be nearer 9. Non-thermal line widths show broader profiles at the tornado location when compared to the surrounding corona. We discuss the differential emission measure in both the tornado and the prominence body, which suggests that there is more contribution in the tornado at temperatures below log T = 6.0 than in the prominence. A movie is available in electronic form at http://www.aanda.org

a Climatology of Synoptic Scale Atmospheric Structure Prior to Severe Convective Storms

NASA Astrophysics Data System (ADS)

Taylor, Gregory Eugene

1982-03-01

This investigation determines those unique properties of the thermodynamic and kinematic structure of the atmosphere in the region where tornado bearing thunderstorms develop as compared to surrounding locations. One hundred five upper air soundings from the operational rawinsonde network, hereafter called tornado proximity soundings, comprise the core of the data base. In each instance, a confirmed tornado occurred within 50 statute miles of and within 105 minutes after the release of the radiosonde. In earlier research of this nature, the thermodynamic and kinematic properties of the atmosphere in the region of tornado bearing thunderstorm development were interpolated or inferred from upper air soundings made at locations surrounding the severe storm location. These surrounding locations, however, were characterized by at most non-tornado bearing thunderstorm development. In this investigation, however, measurements of the atmospheric structure near in space and time to the subsequent tornado bearing thunderstorm development have been utilized. This fact should enhance the probability of detecting the presumably unique properties of the atmospheric structure prior to severe storm development as compared to previous investigations. Height, temperature, mixing ratio, and U and V wind component data from the tornado proximity sounding station and surrounding upper air stations were objectively analyzed to a regularly spaced three dimensional grid network centered on the tornado proximity sounding station. From the basic data, a large number of derived variables which had been previously linked to severe storms were computed. Each case was categorized into one of six different classifications based on the geographical location and date of the tornado proximity sounding. The results from the six categories indicate that the most pronounced unique properties of the pre-severe storm environment are within the lower levels of the atmosphere. In particular, the low level moisture content and the low level V-component tended to maximize near the region of subsequent severe storm development in most of the six categories. Also, a number of variables which are highly dependent upon low level moisture content and/or low level wind data such as horizontal moisture flux and stability indices delineated well the region of subsequent severe storm development.

Pressure at the ground in a large tornado

NASA Astrophysics Data System (ADS)

Winn, W. P.; Hunyady, S. J.; Aulich, G. D.

1999-09-01

A number of instruments were placed on the ground across the path of a large tornado that passed west of the town of Allison, Texas, on June 8, 1995. The center of the tornado came within 660 m of the closest instrument, which recorded a pressure drop of 55 mbar and a subsequent pressure rise of 60 mbar. During the lowest recorded pressures (near r = 660 m), there were large and rapid pressure fluctuations; the largest fluctuation was a 10-mbar spike lasting 2 s. A second instrument on the opposite side of the tornado recorded a pressure drop of 26 mbar. From the pressure variations with time P(t) at the two instruments, the variation of pressure with distance p(r) from the center of the tornado has been deduced for r>660 m. As r decreases, the measured pressure function p(r) drops more abruptly than would be expected from conservation of angular momentum of air spiraling inward near the ground level.

Infrasonic Emissions From A Tornado

NASA Astrophysics Data System (ADS)

Petrin, Christopher; Elbing, Brian

2017-11-01

Tornadoes cause dozens of deaths and significant damage throughout the United States every year. Tornado-producing storm systems emit infrasound (sound at frequencies below human hearing) up to 2 hours before tornadogenesis. Weak atmospheric attenuation at these frequencies allows them to be detected hundreds of miles away. Hence, passive infrasonic monitoring may be used for long-range study of tornadogenesis. This requires characterization of infrasound during the life of a tornado and from other background sources. This is being accomplished as part of the Collaboration Leading Operational UAS Development for Meteorology and Atmospheric Physics (CLOUD-MAP) project, a multi-university collaboration focused on the development and implementation of unmanned aerial systems (UAS) and their integration with sensors for atmospheric measurement. This presentation will report findings from a fixed infrasonic microphone that has been continuously monitoring the atmosphere since September 2, 2016. Infrasound from a tornado that occurred 19 km from the microphone on May 11, 2017 will be presented as well as an overview of other infrasonic observations. This work was supported by NSF Grant 1539070.

Role of electric discharges in the generation of atmospheric vortices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sinkevich, O. A., E-mail: oleg.sinkevich@itf.mpei.ac.ru; Maslov, S. A., E-mail: sergm90@mail.ru; Gusein-zade, N. G., E-mail: ngus@mail.ru

The existing thermohydrodynamic and hydroelectromagnetic models of tornado are considered. The potentialities of the humid atmosphere as a heat engine generating air vortices are analyzed in detail. The ability of long-term atmospheric electric discharges to form a tornado funnel and create an initial twist of up to 10{sup –3}–10{sup –2} s{sup –1} in it are estimated. The possible effect of a lightning discharge on the initiation and evolution of the tornado is discussed. It is shown that the electric current flowing along the lightning channel can lead to helical instability and generation of a weak primary vortex. The channel formedmore » in the atmosphere by a lightning discharge and the vortex motion of the parent thundercloud can enhance the primary vortex and promote its transformation into a tornado. Possible mechanisms of enhancement of the primary vortex created by a lightning discharge and the possibility of its transformation into a tornado in the postdischarge stage are discussed.« less

Wind/Tornado Guidelines Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, D.S.; Holman, G.S.

1991-10-01

This report documents the strategy employed to develop recommended wind/tornado hazard design guidelines for a New Production Reactor (NRP) currently planned for either the Idaho National Engineering Laboratory (INEL) or the Savannah River (SR) site. The Wind/Tornado Working Group (WTWG), comprising six nationally recognized experts in structural engineering, wind engineering, and meteorology, formulated an independent set of guidelines based on site-specific wind/tornado hazard curves and state-of-the-art tornado missile technology. The basic philosophy was to select realistic wind and missile load specifications, and to meet performance goals by applying conservative structural response evaluation and acceptance criteria. Simplified probabilistic risk analyses (PRAs)more » for wind speeds and missile impact were performed to estimate annual damage risk frequencies for both the INEL and SR sites. These PRAs indicate that the guidelines will lead to facilities that meet the US Department of Energy (DOE) design requirements and that the Nuclear Regulatory Commission guidelines adopted by the DOE for design are adequate to meet the NPR safety goals.« less

Risk factors for tornado injuries.

PubMed

Eidson, M; Lybarger, J A; Parsons, J E; MacCormack, J N; Freeman, J I

1990-12-01

Tornadoes in North and South Carolina on 28 March 1984 caused 252 people to be injured seriously enough to require hospitalization and 59 to be killed. To evaluate risk factors, we gathered information on 238 (94%) of those hospitalized and 46 (78%) of those killed. Those hospitalized or deceased had statistically significantly more deep cuts, concussions, unconsciousness and broken bones than those with them at the time of the tornado who were not hospitalized or killed. People living in mobile homes were more likely to be hospitalized or die than people occupying conventional houses. Other risk factors for hospitalization or death included advanced age (60+ years), no physical protection (not having been covered with a blanket or other object), having been struck by broken window glass or other falling objects, home lifted off its foundation, collapsed ceiling or floor, or walls blown away. More awareness of the tornado risk before it strikes and better adherence to tornado protection guidelines could reduce injuries and deaths in the future.

Geophysical Measurements Using a Ring Laser

NASA Astrophysics Data System (ADS)

Lamb, Angela

2016-03-01

Low frequency infrasound from weather related events has been studied for a number of years. In this poster, the results from using a large active ring laser as an infrasound detector are presented. A slightly modified cavity design enhances the interferometer's sensitivity to infrasound. Our results qualitatively agree with several findings from a long term study of weather generated infrasound by NOAA. On April 27, 2014, the 66 km track of an EF-4 tornado passed within 21 km of the ring laser interferometer. An FFT of the ring laser interferometer output revealed a steady tornado generated frequency of 0.94 Hz. The track also passed close to the US Array Transportable Station W41B. This provided the opportunity to examine both the infrasound and ground motion generated by the tornado. Infrasound from three other tornadoes is also included. In all cases the infrasound was detected approximately 30 minutes before the tornado funnel was observed. This work is generously supported by the National Science Foundation and NASA/Arkansas Space Grant.

Contrasting environments associated with storm prediction center tornado outbreak forecasts using synoptic-scale composite analysis

NASA Astrophysics Data System (ADS)

Bates, Alyssa Victoria

Tornado outbreaks have significant human impact, so it is imperative forecasts of these phenomena are accurate. As a synoptic setup lays the foundation for a forecast, synoptic-scale aspects of Storm Prediction Center (SPC) outbreak forecasts of varying accuracy were assessed. The percentages of the number of tornado outbreaks within SPC 10% tornado probability polygons were calculated. False alarm events were separately considered. The outbreaks were separated into quartiles using a point-in-polygon algorithm. Statistical composite fields were created to represent the synoptic conditions of these groups and facilitate comparison. Overall, temperature advection had the greatest differences between the groups. Additionally, there were significant differences in the jet streak strengths and amounts of vertical wind shear. The events forecasted with low accuracy consisted of the weakest synoptic-scale setups. These results suggest it is possible that events with weak synoptic setups should be regarded as areas of concern by tornado outbreak forecasters.

The Evolution Of Dual Status Command Authorities: A New Construct For Implementation

DTIC Science & Technology

2016-02-13

Unity of Command Tornados in Tuscaloosa, Alabama Highlight Command and Control Gaps The response in Tuscaloosa following a series of devastating... tornados that ripped through the city on 27 April 2011 illustrates how personality and not formal structures were the basis of response. Mayor Walter...Multijurisdictional Incidents None of the cases reviewed—Hurricanes Katrina and Sandy, the Tuscaloosa tornados , and the Boston Marathon bombings

Impact of dual-polarization radar technology and Twitter on the Hattiesburg, Mississippi tornado.

PubMed

Cates, Alexis L; Arnold, Brent W; Cooper, Guy Paul; Yeager, Violet; Stake, Josh; Ali, Mohammed; Calderone, Richard C; Wilkinson, James; Hsu, Edbert; Parrillo, Steven; Piper, Steven; Subbarao, Italo

2013-12-01

Dual-Polarization Radar and Twitter were analyzed to determine the impact on injuries sustained by the Hattiesburg EF-4 tornado. Tracking data provided from the Dual-Pol radar systems in National Weather Service Jackson were reviewed. Twitter data from four local Twitter handles were obtained. The change in tweets and followers for the day of the storm were compared to historical averages. A Student t-test was utilized in determining statistical significance (p<0.05). Medical records from two local emergency departments were reviewed for patients treated up to 24 hours after the tornado. An Injury Severity Score (ISS) was calculated for trauma records related to the tornado. Radar detection of the tornado gave approximately 30 minutes of advanced warning time. Statistical significance in follower growth was seen in all four Twitter handles. Out of 50 patients, the average ISS was 3.9 with a range of 1 to 29. There were zero fatalities. An ISS average of 3.9 was significantly less than two previous tornadoes of similar strength that occurred prior to increased usage of Dual-pol radar and Twitter as a means for communicating severe weather information. Early detection from Dual-pol radar improved warning time. Tweets informed citizens to seek appropriate shelter. (Disaster Med Public Health Preparedness. 2013;7:585-592).

Vegetation Disturbance and Recovery Following a Rare Windthrow Event in the Great Smoky Mountains National Park

NASA Astrophysics Data System (ADS)

Bernardes, S.; Madden, M.

2016-06-01

The tornado outbreak of April 2011 in the Southeastern United States caused major damage to property and natural ecosystems. During the outbreak, the Great Smoky Mountains National Park (GRSM) was hit by an EF4 tornado, resulting in a long strip of broken branches and toppled old-growth forest trees. Little is known of the consequences of extreme windthrow events, partly due to limitations in characterizing and monitoring wind-driven vegetation disturbance and recovery over large areas and over time. This work analyzed vegetation damage in the GRSM resulting from the 2011 tornado outbreak and monitored vegetation recovery in the region over a four-year period. Anomalies of the Enhanced Vegetation Index (EVI) calculated using Landsat scenes showed that the 2011 tornado affected 21.38 km2 of forest, including submesic to mesic oak/hardwoods, Southern Appalachian cove hardwood forests and montane alluvial forests. Tornado damage severity was mapped and investigated by using anomalies of EVI over space and time and showed track discontinuity and significant variation in damage intensity along the tornado track, suggesting vortex-topography interactions. Temporal profiles and spatial representations of EVI anomalies for the period 2011-2015 indicated that EVI in 2015 was above pre-event values, indicating homogeneous canopy and lack of vertical structure during regrowth.

Disaster planning: meeting the challenge of 'killer' tornadoes.

PubMed

1997-09-01

In many areas of the country, tornadoes represent a major concern for hospitals in preparing disaster plans. Like all such plans, the hope is that they will not have to be put to use. But last spring, in areas of Arkansas and Texas, damage and casualties from twisters made national headlines and put the disaster plans of a number of hospitals to the test. For example, as part of the country's worst tornado outbreak since March 1994, twisters that tore through Arkansas from southwest to northeast on the afternoon of Saturday, March 1, killed 25 and injured hundreds. The tornadoes left a path of damaged buildings and downed trees more than 200 miles long. Three persons died in the Little Rock suburb of College Station. Warning sirens and TV and radio broadcasts a few minutes before the tornadoes hit were able to give area residents time to take cover, reducing the number of casualties. On May 27, tornadoes that hit three central Texas counties killed 32 people and left hundreds homeless. The small town of Jarrell was flattened by winds of up to 270 mph. In Cedar Park, about 20 miles south of Jarrell, a grocery store was demolished and a nearby shopping center had roofs torn off. Fortunately, there were relatively few injuries. In the area immediately around Jarrell, hospitals reported 33 casualties treated. The small number of injuries may have been the result of a large number of deaths, one official speculated. In this report, we'll give details on how nine hospitals in the affected areas dealt with tornado emergencies and how their disaster plans were carried out.

Tornado Warning Perception and Response: Integrating the Roles of Visual Design, Demographics, and Hazard Experience.

PubMed

Schumann, Ronald L; Ash, Kevin D; Bowser, Gregg C

2018-02-01

Recent advancements in severe weather detection and warning dissemination technologies have reduced, but not eliminated, large-casualty tornado hazards in the United States. Research on warning cognition and behavioral response by the public has the potential to further reduce tornado-related deaths and injuries; however, less research has been conducted in this area compared to tornado research in the physical sciences. Extant research in this vein tends to bifurcate. One branch of studies derives from classic risk perception, which investigates cognitive, affective, and sociocultural factors in relation to concern and preparation for uncertain risks. Another branch focuses on psychological, social, and cultural factors implicated in warning response for rapid onset hazards, with attention paid to previous experience and message design. Few studies link risk perceptions with cognition and response as elicited by specific examples of warnings. The present study unites risk perception, cognition, and response approaches by testing the contributions of hypothesized warning response drivers in one set of path models. Warning response is approximated by perceived fear and intended protective action as reported by survey respondents when exposed to hypothetical tornado warning scenarios. This study considers the roles of hazard knowledge acquisition, information-seeking behaviors, previous experience, and sociodemographic factors while controlling for the effects of the visual warning graphic. Findings from the study indicate the primacy of a user's visual interpretation of a warning graphic in shaping tornado warning response. Results also suggest that information-seeking habits, previous tornado experience, and local disaster culture play strong influencing roles in warning response. © 2017 Society for Risk Analysis.

Community emergency department utilization following a natural disaster (the Goderich Tornado).

PubMed

Appavoo, Samuel D; Khemlin, Alexander; Appavoo, Donna M; Flynn, Candi J

2016-01-01

On 21 August 2011 an F3 tornado hit the Canadian town of Goderich, Ontario, leaving 40 people injured and one dead. Specific medium-term changes in utilization of health care following a disaster have not been analyzed in medical literature. Documenting the emergency department utilization through this subacute period would be helpful to enable institutions and healthcare practitioners to be better prepared for future events. A medical chart review was conducted at the Alexandra Marine and General Hospital in Goderich. All emergency department visits made during the 30 days after the Tornado in 2011 (intervention group), 30 days prior to the tornado in 2011 (primary control group), and during the similar calendar period of 30 days after the tornado in 2010 (seasonal control group) were reviewed. Medical diagnoses of all patients who presented at the emergency department were collected and compared. Fewer people presented to the emergency department following the tornado than during the control periods, and those who did were significantly older than those who presented in the control periods (p<0.001). A significantly greater number of patients presented with undiagnosed medical problems, many came to refill their medications, and significantly fewer people left the emergency department without being seen (p<0.001). This study identifies the medical conditions that are most likely to be seen in an emergency department following a tornado in a rural Ontario community. This information serves to inform the medical community and other hospitals how to increase their level of preparedness should a comparable disaster occur again in the future.

Estimating dispersion from a tornado vortex and mesocyclone

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weber, A.H.; Hunter, C.H.

Atmospheric dispersion modeling is required to ensure that a postulated breach in radionuclide storage containers at the Savannah River Site (SRS) from a tornado strike of Fujita-scale intensity F2 or higher will not result in an unacceptable dose to individuals. Fujita-scale tornado descriptions are included in Appendix A of this report. Dispersion models previously used at SRS for estimating dispersion following a tornado strike were developed by D.W. Pepper in 1975 (DP-1387, Dispersion of Small Particles) and H.R. Haynes and D.W. Taylor in 1983 (DPST-82-982, Estimating Doses from Tornado Winds). Research conducted in 1983 on the formation and evolution ofmore » tornadic thunderstorms has lead to a more complete understanding of the tornado vortex and associated persistent updraft and downdraft regions within the parent thunderstorm. To ensure that appropriate, contemporary methods are used for safety analysis, the Pepper model and the Haynes and Taylor model were evaluated with respect to current knowledge of circulations within tornadic thunderstorms. Pepper`s model is complex numerically but contains most of the desired physical parameterizations. Haynes and Taylor`s model is used with the Puff-Plume model (an emergency response model on the Weather INformation and Display System at SRS) and has provisions for radionuclide deposition and rainout. Haynes and Taylor assumed heavy rain following the tornado for a period of ten minutes, followed by a lighter rain for another ten minutes, then no rain for the period when the material is transported to 100 km downwind. However, neither model incorporates the effects of a nearby thunderstorm downdraft.« less

Simulation of the Tornado Event of 22 March, 2013 over Brahmanbaria, Bangladesh using WRF Model with 3DVar DA techniques

NASA Astrophysics Data System (ADS)

Ahasan, M. N.; Alam, M. M.; Debsarma, S. K.

2015-02-01

A severe thunderstorm produced a tornado (F2 on the enhanced Fujita-Pearson scale), which affected the Brahmanbaria district of Bangladesh during 1100-1130 UTC of 22 March, 2013. The tornado consumed 38, injured 388 and caused a huge loss of property. The total length travelled by the tornado was about 12-15 km and about 1728 households were affected. An attempt has been made to simulate this rare event using the Weather Research and Forecasting (WRF) model. The model was run in a single domain at 9 km resolution for a period of 24 hrs, starting at 0000 UTC on 22 March, 2013. The meteorological conditions that led to form this tornado have been analyzed. The model simulated meteorological conditions are compared with that of a `no severe thunderstorm observed day' on 22 March, 2012. Thus, the model also ran in the same domain at same resolution for 24 hrs, starting at 0000 UTC on 22 March, 2012. The model simulated meteorological parameters are consistent with each other, and all are in good agreement with the observation in terms of the region of occurrence of the tornado activity. The model has efficiently captured the common favourable synoptic conditions for the occurrence of severe tornadoes though there are some spatial and temporal biases in the simulation. The wind speed is not in good agreement with the observation as it has shown the strongest wind of only 15-20 ms-1, against the estimated wind speed of about 55 ms-1. The spatial distributions as well as intensity of rainfall are also in good agreement with the observation. The results of these analyses demonstrated the capability of high-resolution WRF model with 3DVar Data Assimilation (DA) techniques in simulation of tornado over Brahmanbaria, Bangladesh.

Flight Dynamics and Control of a Morphing UAV: Bio inspired by Natural Fliers

DTIC Science & Technology

2017-02-17

Approved for public release: distribution unlimited. IV Modelling and Sizing Tornado Vortex Lattice Method (VLM) was used for aerodynamic prediction... Tornado is a Vortex Lattice Method software programmed in MATLAB; it was selected due to its fast solving time and ability to be controlled through...custom MATLAB scripts. Tornado VLM models the wing as thin sheet of discrete vortices and computes the pressure and force distributions around the

Development of a tornado safe room door from wood Products: door design and impact testing

Treesearch

Robert H. Falk; James J. Bridwell

2016-01-01

In this study, a tornado safe room door built from wood products and steel sheeting was developed and impact-tested according to tornado safe room standards. Results indicate that an door constructed from as few as two sheets of 23/32-in. (18.26-mm) construction-grade plywood and overlaid with 18-gauge (0.05-in.- (1.27- mm-) thick) steel can pass the required impact...

The medical impact of tornadoes in North America.

PubMed

Bohonos, J J; Hogan, D E

1999-01-01

North America suffers some of the most severe tornado disasters of any location on the planet. Significant injury and economic impact may result from these storms, particularly in rural areas. Tornadic storms present unique problems for prehospital and Emergency Department personnel. Soft tissue injuries seen after tornadoes are contaminated with polymicrobial flora and may require delayed primary closure. Fractures are a frequent cause of hospital admission and head injury is a frequent cause of death. Advanced warning and proper sheltering actions by a population are the most significant factors in reducing morbidity and mortality. This article reviews the pertinent literature on the medical impact of tornadoes and details the mechanisms of injury, nature of injuries, pre-hospital and ED planning points associated with tornadic storms.

Development of a design basis tornado and structural design criteria for Lawrence Livermore Laboratory's Site 300

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, J.R.; Minor, J.E.; Mehta, K.C.

1975-11-01

Criteria are prescribed and guidance is provided for professional personnel who are involved with the evaluation of existing buildings and facilities at Site 300 near Livermore, California to resist the possible effects of extreme winds and tornadoes. The development of parameters for the effects of tornadoes and extreme winds and guidelines for evaluation and design of structures are presented. The investigations conducted are summarized and the techniques used for arriving at the combined tornado and extreme wind risk model are discussed. The guidelines for structural design methods for calculating pressure distributions on walls and roofs of structures and methods formore » accommodating impact loads from missiles are also presented. (auth)« less

Development of a design basis tornado and structural design criteria for the Nevada Test Site, Nevada. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, J.R.; Minor, J.E.; Mehta, K.C.

1975-06-01

In order to evaluate the ability of critical facilities at the Nevada Test Site to withstand the possible damaging effects of extreme winds and tornadoes, parameters for the effects of tornadoes and extreme winds and structural design criteria for the design and evaluation of structures were developed. The meteorological investigations conducted are summarized, and techniques used for developing the combined tornado and extreme wind risk model are discussed. The guidelines for structural design include methods for calculating pressure distributions on walls and roofs of structures and methods for accommodating impact loads from wind-driven missiles. Calculations for determining the design loadsmore » for an example structure are included. (LCL)« less

49 CFR 390.5 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-10-01

..., receive, or read text. Emergency means any hurricane, tornado, storm (e.g. thunderstorm, snowstorm... fuel) or otherwise immediately threatens human life or public welfare, provided such hurricane, tornado...

49 CFR 390.5 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-10-01

..., receive, or read text. Emergency means any hurricane, tornado, storm (e.g. thunderstorm, snowstorm... fuel) or otherwise immediately threatens human life or public welfare, provided such hurricane, tornado...

The Severe Weather Outbreak of 10 November 2002: Lightning and Radar Analysis of Storms in the Deep South

NASA Technical Reports Server (NTRS)

Buechler, D. E.; McCaul, E. W., Jr.; Goodman, S. J.; Blakeslee, R. J.; Bailey, J. C.; Gatlin, P.

2004-01-01

On the afternoon and evening of 10 November 2002, the Midwest and Deep South were struck by a major outbreak of severe storms that produced some 80 tornadoes. In terms of number of tornadoes, this was the largest outbreak in the United States since November 1992. Some 32 of the tornadoes occurred in Tennessee, Mississippi, Alabama and Georgia, including several long-track killers. We use the North Alabama Lightning Mapping Array (LMA) and other data sources to perform a comprehensive analysis of the structure and evolution of the outbreak. Most of the Southern tornadoes occurred in isolated, fast-moving supercell storms that formed in warm, moist air ahead of a major cold front. Storms tended to form in lines parallel to storm cell motion, resulting in many communities being hit multiple times by severe storms that evening. Supercells in Tennessee produced numerous strong tornadoes with short to medium-length track paths, while the supercells further south produced several very long-track tornadoes. Radar data indicate that the Tennessee storms tended to split frequently, apparently limiting their ability to sustain long-lived tornadoes, while storms further south split at most one time. The differences between these storms appear to be related to the presence of stronger jetstream winds in Tennessee relative to those present in Mississippi, Alabama and Georgia. LMA-derived flash rates associated with most of the supercell storm cores were about 1-2 flashes per second. Rapid increases in lightning rates (or "jumps") occurred prior to tornado touchdown in many instances. Lightning "holes" (lightning-free regions associated with the echo-free vault) occurred in two of the Tennessee supercells. The complexity of the relationship between lightning and storm severity is revealed by the behavior of one Alabama supercell, which produced a peak flash rate of nearly 14 flashes per second, well after the end of its long-track tornado, while interacting and ultimately merging with a daughter supercell on its southwest flank. Close examination of this powerful storm indicates that its prodigious flash rate was the result of strong flash activity over an unusually large area, rather than a concentrated core of extremely high flash rate activity.

Working after a tornado: a survey of hospital personnel in Joplin, Missouri.

PubMed

Charney, Rachel; Rebmann, Terri; Flood, Robert G

2014-01-01

In 2011, an EF5 tornado hit Joplin, MO, requiring complete evacuation of 1 hospital and a patient surge to another. We sought to assess the resilience of healthcare workers in these hospitals as measured by number reporting to work, willingness to work, personal disaster preparedness, and childcare responsibilities following the disaster. In May 2013, a survey was distributed to healthcare workers at both Joplin hospitals that asked them to report their willingness to work and personal disaster preparedness following various disaster scenarios. For those with childcare responsibilities, scheduling, costs, and impact of hypothetical alternative childcare programs were considered in the analyses. A total of 1,234 healthcare workers completed the survey (response rate: 23.4%). Most (87.8%) worked the week following the Joplin tornado. Healthcare workers report more willingness to work during a future earthquake or tornado compared to their pre-Joplin tornado attitudes (86.2 vs 88.4%, t=-4.3, p<.001; 88.4 vs 90%, t=-3.1, p<.01, respectively), with no change during other scenarios. They expressed significantly higher post-tornado personal disaster preparedness, but only preevent preparedness was a significant predictor of postevent preparedness. Nearly half (48.5%, n=598) had childcare responsibilities; 61% (n=366) had childcare needs the week of the tornado, and 54% (n=198) required the use of alternative childcare. If their hospital had provided alternative childcare, 51% would have used it and 42% felt they would have been more willing to report to work. Most healthcare workers reported to work following this disaster, demonstrating true resilience. Disaster planners should be aware of these perceptions as they formulate their own emergency operation plans.

Prevalence and predictors of PTSD and depression among adolescent victims of the Spring 2011 tornado outbreak

PubMed Central

Adams, Zachary W.; Sumner, Jennifer A.; Danielson, Carla Kmett; McCauley, Jenna L.; Resnick, Heidi S.; Grös, Kirstin; Paul, Lisa A.; Welsh, Kyleen E.; Ruggiero, Kenneth J.

2014-01-01

Background Relatively few studies have examined prevalence and predictors of posttraumatic stress disorder (PTSD) or major depressive episode (MDE) in disaster-affected adolescents. Fewer still have administered diagnostic measures or studied samples exposed to tornadoes, a common type of disaster. Further, methodological problems limit the generalizability of previous findings. This study addressed prevalence estimates and risk factors for PTSD and MDE among adolescents exposed to the spring 2011 tornado outbreak in Alabama and Joplin, Missouri. Methods A large (N=2,000), population-based sample of adolescents and caregivers, recruited randomly from tornado-affected communities, participated in structured telephone interviews. PTSD and MDE prevalence were estimated for the overall sample, by gender, and by age. Hierarchical logistic regression was used to identify risk factors for PTSD and MDE. Results Overall, 6.7% of adolescents met diagnostic criteria for PTSD and 7.5% of adolescents met diagnostic criteria for MDE since the tornado. Girls were significantly more likely than boys to meet diagnostic criteria for MDE, and older adolescents were more likely than younger adolescents to report MDE since the tornado. Female gender, prior trauma exposure, and an injured family member were associated with greater risk for PTSD and MDE. Specific incident characteristics (loss of services, concern about others’ safety) were associated with greater PTSD risk; prior disaster exposure was associated with lower MDE risk. Conclusions Whereas most adolescents were resilient following tornado exposure, roughly 1 in 15 developed PTSD, 1 in 13 developed MDE, and many more endorsed subclinical mental health problems. Information regarding specific risk factors can guide early screening, prevention, and intervention efforts in disaster-affected communities. PMID:24580551

Prevalence and predictors of PTSD and depression among adolescent victims of the Spring 2011 tornado outbreak.

PubMed

Adams, Zachary W; Sumner, Jennifer A; Danielson, Carla Kmett; McCauley, Jenna L; Resnick, Heidi S; Grös, Kirstin; Paul, Lisa A; Welsh, Kyleen E; Ruggiero, Kenneth J

2014-09-01

Relatively few studies have examined prevalence and predictors of posttraumatic stress disorder (PTSD) or major depressive episode (MDE) in disaster-affected adolescents. Fewer still have administered diagnostic measures or studied samples exposed to tornadoes, a common type of disaster. Further, methodologic problems limit the generalizability of previous findings. This study addressed prevalence estimates and risk factors for PTSD and MDE among adolescents exposed to the Spring 2011 tornado outbreak in Alabama and Joplin, Missouri. A large (N = 2000), population-based sample of adolescents and caregivers, recruited randomly from tornado-affected communities, participated in structured telephone interviews. PTSD and MDE prevalence were estimated for the overall sample, by gender, and by age. Hierarchical logistic regression was used to identify risk factors for PTSD and MDE. Overall, 6.7% of adolescents met diagnostic criteria for PTSD and 7.5% of adolescents met diagnostic criteria for MDE since the tornado. Girls were significantly more likely than boys to meet diagnostic criteria for MDE, and older adolescents were more likely than younger adolescents to report MDE since the tornado. Female gender, prior trauma exposure, and an injured family member were associated with greater risk for PTSD and MDE. Specific incident characteristics (loss of services, concern about others' safety) were associated with greater PTSD risk; prior disaster exposure was associated with lower MDE risk. However, most adolescents were resilient following tornado exposure, roughly 1 in 15 developed PTSD, 1 in 13 developed MDE, and many more endorsed subclinical mental health problems. Information regarding specific risk factors can guide early screening, prevention, and intervention efforts in disaster-affected communities. © 2014 The Authors. Journal of Child Psychology and Psychiatry. © 2014 Association for Child and Adolescent Mental Health.

Re-interpreting Prominences Classified as Tornadoes

NASA Astrophysics Data System (ADS)

Martin, Sara F.; Venkataramanasastry, Aparna

2015-04-01

Some papers in the recent literature identify tornado prominences with barbs of quiescent prominences while papers in the much older historic literature include a second category of tornado prominence that does not correspond to a barb of a quiescent prominence. The latter are described as prominence mass rotating around a nearly vertical axis prior to its eruption and the rotation was verified by spectral measurements. From H alpha Doppler-shifted mass motions recorded at Helio Research or the Dutch Open Telescope, we illustrate how the apparent tornado-like motions, identified with barbs, are illusions in our mind’s eye resulting from poorly resolved counterstreaming threads of mass in the barbs of quiescent prominences. In contrast, we confirm the second category of rotational motion in prominences shortly before and during eruption. In addition, we identify this second category as part of the late phase of a phenomenon called the roll effect in erupting prominences. In these cases, the eruption begins with the sideways rolling of the top of a prominence. As the eruption proceeds the rolling motion propagates down one leg or both legs of the prominence depending on whether the eruption is asymmetric or symmetric respectively. As an asymmetric eruption continues, the longer lasting leg becomes nearly vertical and its rotational motion also continues. If only this phase of the eruption was observed, as in some historic cases, it was called a tornado prominence. However, when we now observe entire eruptions in time-lapse sequences, the similarity to terrestrial tornadoes is lost. We conclude that neither prominence barbs, that give the illusion of rotation, nor the cases of true rotational motion, in the legs of erupting prominences, are usefully described as tornado prominences when the complete prominence structure or complete erupting event is observed.

5. 7 MW Tornados for Dunn Paper mill power CHP plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jeffs, E.

The first commercial installation in the United States of Ruston's high efficiency Tornado gas turbine is now fully operational at the Dunn Paper Company's Port Huron, Michigan paper mill where they make special light weight papers for packaging and business forms. It's a cogeneration installation powered by three Tornados and two waste heat recovery boilers which provide the mill with all of its electricity and process steam requirements - at high overall thermal efficiency.

Reduction and analysis of data collected during the electromagnetic tornado experiment

NASA Technical Reports Server (NTRS)

Davisson, L. D.

1976-01-01

Techniques for data processing and analysis are described to support tornado detection by analysis of radio frequency interference in various frequency bands, and sea state determination from short pulse radar measurements. Activities include: strip chart recording of tornado data; the development and implementation of computer programs for digitalization and analysis of the data; data reduction techniques for short pulse radar data, and the simulation of radar returns from the sea surface by computer models.

Tornado disasters and stress responses.

PubMed

Godleski, L S

1997-04-01

Each year, a number of tornados rip through Kentucky, leaving fear, destruction, and human injury in their path. Persons who endure these catastrophes often experience a variety of stress responses. The psychological and medical sequelae include depression, acute and post-traumatic stress disorders, substance abuse, anxiety, and somatization. It is especially important for the Kentucky practitioner to be able to recognize and screen for pathology following a tornado disaster in order to provide leadership in ascertaining treatment for such stress responses.

Finite Element Analysis of Saferooms Subjected to Tornado Impact Loads

NASA Astrophysics Data System (ADS)

Parfilko, Y.; Amaral de Arruda, F.; Varela, B.

2017-10-01

A Tornado is one of the most dreadful and unpredictable events in nature. Unfortunately, weather and geographic conditions make a large portion of the United States prone to this phenomenon. Tornado saferooms are monolithic reinforced concrete protective structures engineered to guard against these natural disasters. Saferooms must withstand impacts and wind loads from EF-5 tornadoes - where the wind speed reaches up to 150 m/s (300 mph) and airborne projectiles can reach up to 50 m/s (100 mph). The objective of this work is to evaluate the performance of a saferoom under impact from tornado-generated debris and tornado-dragged vehicles. Numerical simulations were performed to model the impact problem using explicit dynamics and energy methods. Finite element models of the saferoom, windborne debris, and vehicle models were studied using the LS-DYNA software. RHT concrete material was used to model the saferoom and vehicle models from NCAC were used to characterize damage from impacts at various speeds. Simulation results indicate good performance of the saferoom structure at vehicle impact speeds up to 25 meters per second. Damage is more significant and increases nonlinearly starting at impact velocities of 35 m/s (78 mph). Results of this study give valuable insight into the dynamic response of saferooms subjected to projectile impacts, and provide design considerations for civilian protective structures. Further work is being done to validate the models with experimental measurements.

Magnetohydrodynamic Models of Molecular Tornadoes

NASA Astrophysics Data System (ADS)

Au, Kelvin; Fiege, Jason D.

2017-07-01

Recent observations near the Galactic Center (GC) have found several molecular filaments displaying striking helically wound morphology that are collectively known as molecular tornadoes. We investigate the equilibrium structure of these molecular tornadoes by formulating a magnetohydrodynamic model of a rotating, helically magnetized filament. A special analytical solution is derived where centrifugal forces balance exactly with toroidal magnetic stress. From the physics of torsional Alfvén waves we derive a constraint that links the toroidal flux-to-mass ratio and the pitch angle of the helical field to the rotation laws, which we find to be an important component in describing the molecular tornado structure. The models are compared to the Ostriker solution for isothermal, nonmagnetic, nonrotating filaments. We find that neither the analytic model nor the Alfvén wave model suffer from the unphysical density inversions noted by other authors. A Monte Carlo exploration of our parameter space is constrained by observational measurements of the Pigtail Molecular Cloud, the Double Helix Nebula, and the GC Molecular Tornado. Observable properties such as the velocity dispersion, filament radius, linear mass, and surface pressure can be used to derive three dimensionless constraints for our dimensionless models of these three objects. A virial analysis of these constrained models is studied for these three molecular tornadoes. We find that self-gravity is relatively unimportant, whereas magnetic fields and external pressure play a dominant role in the confinement and equilibrium radial structure of these objects.

Comparisons Between Total Lightning Data, Mesocyclone Strength, and Storm Damage Associated with the Florida Tornado Outbreak of February 23, 1998

NASA Technical Reports Server (NTRS)

Hodanish, S; Sharp, D.; Williams, E.; Boldi, B.; Goodman, Steven J.; Raghavan, R.; Matlin, A.; Weber, M.

1998-01-01

During the early morning hours of February 23 1998, the worst tornado outbreak ever recorded occurred over the central Florida peninsula. At least 7 confirmed tornadoes, associated with 4 supercells, developed, with 3 of the tornadoes reaching F3 intensity. Many of the tornadoes where on the ground for tens of miles, uncommon for the state of Florida. A total of 42 people were killed, with over 250 people injured. During the outbreak, National Weather Service Melbourne, in collaboration with the National Aeronautics and Space Administration and the Massachusetts Institute of Technology was collecting data from a unique lightning observing system called Lightning Imaging Sensor Data Applications Display (LISDAD, Boldi et.al., this conference). This system marries radar data collected from the KMLB WSR-88D, cloud to ground data collected from the National Lightning Detection Network, and total lightning data collected from NASKs Lightning Detection And Ranging system. This poster will display, concurrently, total lightning data (displayed in 1 minute increments), time/height storm relative velocity products from the KMLB WSR-88D, and damage information (tornado/hail/wind) from each of the supercell thunderstorms. The primary objective of this poster presentation is to observe how total lightning activity changes as the convective storm intensifies, and how the lightning activity changes with respect to mesocyclone strength (vortex stretching) and damaging weather on the ground.

Millimeter-wave Molecular Line Observations of the Tornado Nebula

NASA Astrophysics Data System (ADS)

Sakai, D.; Oka, T.; Tanaka, K.; Matsumura, S.; Miura, K.; Takekawa, S.

2014-08-01

We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15' × 15' area was mapped in the J = 1-0 lines of CO, 13CO, and HCO+ with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V LSR = -14 km s-1 and +5 km s-1. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720 MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado "head" in the -14 km s-1 cloud, also suggesting the interaction. Virial analysis shows that the +5 km s-1 cloud is more tightly bound by self-gravity than the -14 km s-1 cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s-1 cloud collided into the -14 km s-1 cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.

Hα Doppler shifts in a tornado in the solar corona

NASA Astrophysics Data System (ADS)

Schmieder, B.; Mein, P.; Mein, N.; Levens, P. J.; Labrosse, N.; Ofman, L.

2017-01-01

Context. High resolution movies in 193 Å from the Atmospheric Imaging Assembly (AIA) on the Solar Dynamic Observatory (SDO) show apparent rotation in the leg of a prominence observed during a coordinated campaign. Such structures are commonly referred to as tornadoes. Time-distance intensity diagrams of the AIA data show the existence of oscillations suggesting that the structure is rotating. Aims: The aim of this paper is to understand if the cool plasma at chromospheric temperatures inside the tornado is rotating around its central axis. Methods: The tornado was also observed in Hα with a cadence of 30 s by the MSDP spectrograph, operating at the Solar Tower in Meudon. The MSDP provides sequences of simultaneous spectra in a 2D field of view from which a cube of Doppler velocity maps is retrieved. Results: The Hα Doppler maps show a pattern with alternatively blueshifted and redshifted areas of 5 to 10'' wide. Over time the blueshifted areas become redshifted and vice versa, with a quasi-periodicity of 40 to 60 min. Weaker amplitude oscillations with periods of 4 to 6 min are superimposed onto these large period oscillations. Conclusions: The Doppler pattern observed in Hα cannot be interpreted as rotation of the cool plasma inside the tornado. The Hα velocity observations give strong constraints on the possible interpretations of the AIA tornado.

Summary of efficiency testing of standard and high-capacity high-efficiency particulate air filters subjected to simulated tornado depressurization and explosive shock waves

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, P.R.; Gregory, W.S.

1985-04-01

Pressure transients in nuclear facility air cleaning systems can originate from natural phenomena such as tornadoes or from accident-induced explosive blast waves. This study was concerned with the effective efficiency of high-efficiency particulate air (HEPA) filters during pressure surges resulting from simulated tornado and explosion transients. The primary objective of the study was to examine filter efficiencies at pressure levels below the point of structural failure. Both standard and high-capacity 0.61-m by 0.61-m HEPA filters were evaluated, as were several 0.2-m by 0.2-m HEPA filters. For a particular manufacturer, the material release when subjected to tornado transients is the samemore » (per unit area) for both the 0.2-m by 0.2-m and the 0.61-m by 0.61-m filters. For tornado transients, the material release was on the order of micrograms per square meter. When subjecting clean HEPA filters to simulated tornado transients with aerosol entrained in the pressure pulse, all filters tested showed a degradation of filter efficiency. For explosive transients, the material release from preloaded high-capacity filters was as much as 340 g. When preloaded high-capacity filters were subjected to shock waves approximately 50% of the structural limit level, 1 to 2 mg of particulate was released.« less

Bidirectional tornado modes on the Joint European Torus

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sandquist, P.; Sharapov, S. E.; Lisak, M.

In discharges on the Joint European Torus [P. H. Rebut and B. E. Keen, Fusion Technol. 11, 13 (1987)] with safety factor q(0)<1 and high-power ion cyclotron resonance heating (ICRH), monster sawtooth crashes are preceded by frequency sweeping 'tornado modes' in the toroidal Alfven eigenmode frequency range. A suite of equilibrium and spectral magnetohydrodynamical codes is used for explaining the observed evolution of the tornado mode frequency and for identifying temporal evolution of the safety factor inside the q=1 radius just before sawtooth crashes. In some cases, the tornado modes are observed simultaneously with both positive and negative toroidal modemore » numbers. Hence, a free energy source other than the radial gradient of the energetic ion pressure exciting these modes is sought. The distribution function of the ICRH-accelerated ions is assessed with the SELFO code [J. Hedin et al., Nucl. Fusion 42, 527 (2002)] and energetic particle drive due to the velocity space anisotropy of ICRH-accelerated ions is considered analytically as the possible source for excitation of bidirectional tornado modes.« less

Electrical Characteristics of Simulated Tornadoes and Dust Devils

NASA Technical Reports Server (NTRS)

Zimmerman, Michael I.; Farrell, William M.; Barth, E. L.; Lewellen, W. S.; Perlongo, N. J.; Jackson, T. L.

2012-01-01

It is well known that tornadoes and dust devils have the ability to accumulate significant, visible clouds of debris. Collisions between sand-like debris species produce different electric charges on different types of grains, which convect along different trajectories around the vortex. Thus, significant charge separations and electric currents are possible, which as the vortex fluctuates over time are thought to produce ULF radiation signatures that have been measured in the field. These electric and magnetic fields may contain valuable information about tornado structure and genesis, and may be critical in driving electrochemical processes within dust devils on Mars. In the present work, existing large eddy simulations of debris-laden tornadoes performed at West Virginia University are coupled with a new debris-charging and advection code developed at Goddard Space Flight Center to investigate the detailed (meter-resolution) fluid-dynamic origins of electromagnetic fields within terrestrial vortices. First results are presented, including simulations of the electric and magnetic fields that would be observed by a near-surface, instrument-laden probe during a direct encounter with a tornado.

Framework for modeling urban restoration resilience time in the aftermath of an extreme event

USGS Publications Warehouse

Ramachandran, Varun; Long, Suzanna K.; Shoberg, Thomas G.; Corns, Steven; Carlo, Héctor

2015-01-01

The impacts of extreme events continue long after the emergency response has terminated. Effective reconstruction of supply-chain strategic infrastructure (SCSI) elements is essential for postevent recovery and the reconnectivity of a region with the outside. This study uses an interdisciplinary approach to develop a comprehensive framework to model resilience time. The framework is tested by comparing resilience time results for a simulated EF-5 tornado with ground truth data from the tornado that devastated Joplin, Missouri, on May 22, 2011. Data for the simulated tornado were derived for Overland Park, Johnson County, Kansas, in the greater Kansas City, Missouri, area. Given the simulated tornado, a combinatorial graph considering the damages in terms of interconnectivity between different SCSI elements is derived. Reconstruction in the aftermath of the simulated tornado is optimized using the proposed framework to promote a rapid recovery of the SCSI. This research shows promising results when compared with the independent quantifiable data obtained from Joplin, Missouri, returning a resilience time of 22 days compared with 25 days reported by city and state officials.

Detection of atmospheric infrasound with a ring laser interferometer

NASA Astrophysics Data System (ADS)

Dunn, Robert W.; Meredith, John A.; Lamb, Angela B.; Kessler, Elijah G.

2016-09-01

In this paper, the results from using a large active ring laser interferometer as an infrasound detector are presented. On April 27, 2014, an EF4 tornado struck Central Arkansas and passed within 21 km of the ring laser interferometer. The tornado resulted in 16 fatalities and millions of dollars in damage. Using the ring laser to study the tornado infrasound produced results that qualitatively agree with several findings from a long-term study of weather generated infrasound by the National Oceanic and Atmospheric Administration. A Fast Fourier Transform of the ring laser output revealed a coherent frequency of approximately 0.94 Hz that lasted during the life of the storm. The 0.94 Hz frequency was initially observed 30 min before the funnel was reported on the ground. Infrasound signatures from four separate tornadoes are presented. In each case, coherent infrasound was detected at least 30 min before the tornado was reported on the ground. Examples of the detection of distant coherent acoustic-gravity waves from volcanoes and typhoons are also presented. In addition, buoyancy waves were recorded.

Solar Magnetized Tornadoes: Rotational Motion in a Tornado-like Prominence

NASA Astrophysics Data System (ADS)

Su, Yang; Gömöry, Peter; Veronig, Astrid; Temmer, Manuela; Wang, Tongjiang; Vanninathan, Kamalam; Gan, Weiqun; Li, YouPing

2014-04-01

Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtained from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ~5 km s-1.

Tornadoes, Florida's Miami Tequesta Site, Memphremagog, America's Stonehenge, A.S., Mexico/Rumford ME, and Some Applied Physics.

NASA Astrophysics Data System (ADS)

Mc Leod, Edward M.; Mc Leod, David M.; Mc Leod, Roger D.

2002-04-01

Hay or dust devils, firestorm "twisters", waterspouts, and Fujita's entire range of F1 to F5 tornadoes have a completely explainable common source. These can exist only where the earth's electromagnetic field, EMF, makes loops, or their associated breaks and reorganizations, like those observable at sunspots. Fujita's F1 tornadoes require ionized air in modest thunderclouds with ordinary up- or downdrafts. The equivalent charge-velocity vector then is in "cross-product" with the "hypothesized," but detectable, "tubes" of magnetic field. This creates the familiar vortex that the ionic flow forms, which initially emerges somewhat horizontally from the thundercloud; this can work its way down the loop to touchdown. Fujita's F2 and F3 tornadoes may need the intersection of an ionized jet stream with a high-level EMF loop. The F4 and F5 variety possibly require the combined effects of vertical storm drafts and a jet stream to reach rotational speeds of 318 mph. We have been at EMF sites detectable by blue-light phenomena, A.S. and tornado sites visually qualify.

7 CFR 250.3 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... Services. Disaster means (a) Any natural catastrophe (including any hurricane, tornado, storm, high water... subject to the approval of the FNSRO. Situation of distress means (a) A hurricane, tornado, storm, flood...

7 CFR 250.3 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... Services. Disaster means (a) Any natural catastrophe (including any hurricane, tornado, storm, high water... subject to the approval of the FNSRO. Situation of distress means (a) A hurricane, tornado, storm, flood...

7 CFR 250.3 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... Services. Disaster means (a) Any natural catastrophe (including any hurricane, tornado, storm, high water... subject to the approval of the FNSRO. Situation of distress means (a) A hurricane, tornado, storm, flood...

7 CFR 250.3 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... Services. Disaster means (a) Any natural catastrophe (including any hurricane, tornado, storm, high water... subject to the approval of the FNSRO. Situation of distress means (a) A hurricane, tornado, storm, flood...

7 CFR 250.3 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... Services. Disaster means (a) Any natural catastrophe (including any hurricane, tornado, storm, high water... subject to the approval of the FNSRO. Situation of distress means (a) A hurricane, tornado, storm, flood...

Overshooting top behavior of three tornado-producing thunderstorms

NASA Technical Reports Server (NTRS)

Umenhofer, T. A.

1975-01-01

The behavior of overshooting tops and jumping cirrus observed in three tornado-producing thunderstorms during the 1974 Learjet Cloud-Truth experiment is discussed. An investigation of temporal changes in the heights of overshooting domes (conglomerations of overshooting tops with diameters less than 1 km) reveals several distinctive features associated with tornadic events. There is a gradual decrease in dome height prior to tornado touchdown. Minimum dome activity occurred 5 min after, 5.5 min before, and at approximately the same time as the tornadic event in the storms observed. In all cases, dramatic dome growth at a rate of 17 to 23 m/sec immediately followed the occurrence of the minimum dome heights. There is evidence that tornado production is insensitive to the pre-touchdown maximum dome heights between 1 and 3 km.

Ionospheric S-shaped Doppler fluctuations produced by the tornadoes

NASA Technical Reports Server (NTRS)

Hung, R. J.; Rao, G. L.; Smith, R. E.

1974-01-01

A three-dimensional nine element HF-CW Doppler sounder array has been used to detect ionospheric disturbances which may be due to tornadoes. The typical events chosen in the present study occurred on November 20 and 27, 1973. Both events are apparently associated with tornadoes sighted in the Huntsville, Alabama area. The Doppler records show S-shaped waves rather than the quasi-sinusoidal waves observed in conjunction with and apparently due to thunderstorms. The wave-periods are in the range of 6 to 8 minutes instead of the 3 to 5 minute periods associated with thunderstorms. Dissipation of waves is mostly due to the evanescent effect and they cannot propagate very far from the path of the tornado center. A theory is presented which is in good agreement with the observations.

Tornado Strikes Southern Maryland

NASA Technical Reports Server (NTRS)

2002-01-01

Evening light catches the tops of towering thunderheads over the Mid-Atlantic states on April 28, 2002. The powerful storms spawned several tornados, one of which was classified as an F4 tornado. The powerful tornado touched down in the southern Maryland town of La Plata, destroying most of the historic downtown. The twister-one of the strongest ever to hit the state-beat a 24-mile swath running west to east through the state and claimed at least three lives. The image above was taken by the Geostationary Operational Environmental Satellite (GOES) at 7:15 PM Eastern Daylight Savings Time. A large version of the animation shows more detail. (5.9 MB Quicktime) Image courtesy National Oceanic and Atmospheric Administration (NOAA) and the GOES Project Science Office. Animation by Robert Simmon, NASA GSFC.

Medicolegal aspects of tornadic storms in Kansas, U.S.A.

PubMed

Eckert, W G

1991-12-01

Kansas is known for its fierce whether, including tornados in the spring and fall and blizzards in the winter. A recent series of tornados cut a path of destruction a mile wide for greater than 40 miles (64 km), killed 20 people, and caused several hundred casualities on the evening of April 26, 1991, in Tornado Alley, which runs from the northern border of Oklahoma through southern Kansas past Wichita toward Emporium, Kansas. The wind velocity was greater than 200 mph. Twenty people were killed, 17 of these in Andover, Kansas, a small town east of Wichita. Injuries caused by the tornados and the excellent emergency response and care provided by medical, law-enforcement, and volunteer personnel in the wake of the storms are described here.

Observation of acoustic-gravity waves in the upper atmosphere during severe storm activity

NASA Technical Reports Server (NTRS)

Hung, R. J.

1975-01-01

A nine-element continuum wave spectrum, high-frequency, Doppler sounder array has been used to detect upper atmospheric wave-like disturbances during periods with severe weather activity, particularly severe thunderstorms and tornadoes. Five events of severe weather activity, including extreme tornado outbreak of April 3, 1974, were chosen for the present study. The analysis of Doppler records shows that both infrasonic waves and gravity waves were excited when severe storms appeared in the north Alabama area. Primarily, in the case of tornado activity, S-shaped Doppler fluctuations or Doppler fold-backs are observed, while quasi-sinusoidal fluctuations are more common in the case of thunderstorm activity. A criterion for the production of Doppler fold-backs is derived and compared with possible tornado conditions.

24 CFR 203.378 - Property condition.

Code of Federal Regulations, 2010 CFR

2010-04-01

... the Commissioner, the property shall be undamaged by fire, earthquake, flood, or tornado, except as... mortgagee shall be responsible for: (1) Damage by fire, flood, earthquake, hurricane, or tornado; (2) Damage...

49 CFR 390.5 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-10-01

... device used to input, write, send, receive, or read text. Emergency means any hurricane, tornado, storm... public welfare, provided such hurricane, tornado, or other event results in: (1) A declaration of an...

National Weather Service

MedlinePlus

... Data SAFETY Floods Tsunami Beach Hazards Wildfire Cold Tornadoes Fog Air Quality Heat Hurricanes Lightning Safe Boating ... Winter Weather Forecasts River Flooding Latest Warnings Thunderstorm/Tornado Outlook Hurricanes Fire Weather Outlooks UV Alerts Drought ...

24 CFR 203.378 - Property condition.

Code of Federal Regulations, 2011 CFR

2011-04-01

... the Commissioner, the property shall be undamaged by fire, earthquake, flood, or tornado, except as... mortgagee shall be responsible for: (1) Damage by fire, flood, earthquake, hurricane, or tornado; (2) Damage...

24 CFR 203.378 - Property condition.

Code of Federal Regulations, 2013 CFR

2013-04-01

... the Commissioner, the property shall be undamaged by fire, earthquake, flood, or tornado, except as... mortgagee shall be responsible for: (1) Damage by fire, flood, earthquake, hurricane, or tornado; (2) Damage...

24 CFR 203.378 - Property condition.

Code of Federal Regulations, 2014 CFR

2014-04-01

... the Commissioner, the property shall be undamaged by fire, earthquake, flood, or tornado, except as... mortgagee shall be responsible for: (1) Damage by fire, flood, earthquake, hurricane, or tornado; (2) Damage...

24 CFR 203.378 - Property condition.

Code of Federal Regulations, 2012 CFR

2012-04-01

... the Commissioner, the property shall be undamaged by fire, earthquake, flood, or tornado, except as... mortgagee shall be responsible for: (1) Damage by fire, flood, earthquake, hurricane, or tornado; (2) Damage...

49 CFR 390.5 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-10-01

... device used to input, write, send, receive, or read text. Emergency means any hurricane, tornado, storm... public welfare, provided such hurricane, tornado, or other event results in: (1) A declaration of an...

Know Yourself, Define Your Enemy: Presidential Rhetoric and American Strategic Culture

DTIC Science & Technology

2016-06-10

Commander Gareth Prendergast received his commission from the Queen in 2000. Upon qualification in role as a Navigator on the Tornado GR4 fighter...On returning to the Tornado , he successfully deployed the first UK combat air assets in support of the humanitarian crisis in Iraq and...subsequently commanded the RAF Tornado detachment. Wing Commander Prendergast read for a Masters in International Law at Lancaster University and holds a Bachelor degree with honors from Keele University in International Relations.

The Emergence of Organizational Fit: Applying Configuration Theory to the Snohomish County (WA) Emergency Operations Center

DTIC Science & Technology

2016-03-01

2000, Fort Worth Tornado ,” Disaster Prevention and Management 4, no. 5 (2002): 369. 88 T. Andrew Au, “Analysis of Command and Control Networks on...expertise was of minimal assistance. “When FEMA came in, they said, ‘Yes, we do tornadoes and hurricanes and all of this. We have not done this on the...David A. “Coordinating Multi-Organizational Responses to Disaster: Lessons from the March 28, 2000, Fort Worth Tornado .” Disaster Prevention and

Numerical simulation of tornado wind loading on structures

NASA Technical Reports Server (NTRS)

Maiden, D. E.

1976-01-01

A numerical simulation of a tornado interacting with a building was undertaken in order to compare the pressures due to a rotational unsteady wind with that due to steady straight winds used in design of nuclear facilities. The numerical simulations were performed on a two-dimensional compressible hydrodynamics code. Calculated pressure profiles for a typical building were then subjected to a tornado wind field and the results were compared with current quasisteady design calculations. The analysis indicates that current design practices are conservative.

Four hospitals in the path of killer tornadoes--what happened before ... during ... after.

PubMed

Friedrick, Joanne

2012-01-01

In mid-and late-April, late May, and early June of 2011, tornadoes swept across states in the Midwest, South, Southeast, and even New England, killing hundreds, injuring thousands, destroying property in the billions in both rural and urban areas. Some hospitals in areas where the tornadoes struck did not escape damage and one was destroyed. This article describes what happened at four hospitals in cities hardest hit by the storms and the many roles played by security officers.

Disaster Distress Helpline: Wildfires

MedlinePlus

... Tips Anniversaries and Trigger Events Types of Disasters Tornadoes and Severe Storms Hurricanes and Tropical Storms Floods ... While not reported as often as floods or tornadoes and severe storms , they, too, can cause emotional ...

Tornadoes: A Center Approach.

ERIC Educational Resources Information Center

Christman-Rothlein, Liz; Meinbach, Anita M.

1981-01-01

Information is given on how to put together a learning center. Discusses information and activity packets for a complete learning center on tornadoes including objectives, directions, materials, photographs of physical arrangements, and posttest. (DC)

Vertically homogeneous stationary tornado-type vortex

NASA Astrophysics Data System (ADS)

Rutkevich, P. B.; Rutkevych, P. P.

2010-05-01

Tornado is regarded as one of the most dangerous atmosphere phenomena. The tornado phenomenon has been intensively studied so far, however, there is still no established and accepted theory of how tornadoes form, an uncertainty still exists concerning extreme winds and pressure drops in tornadoes. It is commonly accepted that it is possible to describe tornado from the set of nonlinear hydrodynamical equations, however, it is still unclear which non-linear processes are responsible for its formation. Nonlinear terms in the system are associated with either centrifugal force, or entropy transport, or transport of humidity. It appears that the amount and spatial distribution of precipitation with the convection are important indicators of the weather phenomena associated with a particular storm. The low-precipitation supercells that produce relatively little precipitation and yet show clear visual signs of rotation. Low-precipitation supercells occur most often near the surface dryline and, owing to the sparse precipitation and relatively dry environments with little cloudiness. Low-precipitation storms are frequently non-tornadic and many are non-severe despite exhibiting persistent rotation. On the other hand, the so-called high-precipitation storms are characterized by substantial precipitation within their mesocyclonic circulations. When high-precipitation storms have a recognizable hook radar echo, reflectivity in the hook is comparable to those in the precipitation core. High-precipitation supercells are probably the most common form of supercell and produce severe weather of all types including tornadoes. Therefore, in this work we consider a hydrodynamic system with only one nonlinear term associated with atmosphere humidity, which yields energy to the system. The tornado vortex is usually to a good approximation cylindrical so we use cylindrical geometry and homogeneity in vertical direction. In this case the problem reduces to a system of ordinary differential equations. Rotation in the vortex is associated with compressibility so we also take into account the compressibility of the gas. Under certain approximations the problem reduces to a single high-order nonlinear equation. Numerical solution of the obtained high-order equation describes all three velocity components and all thermodynamic parameters in the system. The system exhibits high rotation and strong vertical air flow in the middle part of the vortex.

42 CFR 412.25 - Excluded hospital units: Common requirements.

Code of Federal Regulations, 2013 CFR

2013-10-01

... physical facility or because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (c... (ii) Because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (5) For cost...

32 CFR Appendix A to Part 623 - Explanation of Terms

Code of Federal Regulations, 2010 CFR

2010-07-01

..., or other political subdivision of any State. Major disaster. Any hurricane, tornado, storm, flood.... Threatened major disaster. Any hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave...

32 CFR Appendix A to Part 623 - Explanation of Terms

Code of Federal Regulations, 2011 CFR

2011-07-01

..., or other political subdivision of any State. Major disaster. Any hurricane, tornado, storm, flood.... Threatened major disaster. Any hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave...

32 CFR Appendix A to Part 623 - Explanation of Terms

Code of Federal Regulations, 2013 CFR

2013-07-01

..., or other political subdivision of any State. Major disaster. Any hurricane, tornado, storm, flood.... Threatened major disaster. Any hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave...

42 CFR 412.25 - Excluded hospital units: Common requirements.

Code of Federal Regulations, 2010 CFR

2010-10-01

... physical facility; or (ii) Because of catastrophic events such as fires, floods, earthquakes, or tornadoes... as fires, floods, earthquakes, or tornadoes. (5) For cost reporting periods beginning on or after...

32 CFR Appendix A to Part 623 - Explanation of Terms

Code of Federal Regulations, 2012 CFR

2012-07-01

..., or other political subdivision of any State. Major disaster. Any hurricane, tornado, storm, flood.... Threatened major disaster. Any hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave...

32 CFR Appendix A to Part 623 - Explanation of Terms

Code of Federal Regulations, 2014 CFR

2014-07-01

..., or other political subdivision of any State. Major disaster. Any hurricane, tornado, storm, flood.... Threatened major disaster. Any hurricane, tornado, storm, flood, high water, wind-driven water, tidal wave...

42 CFR 412.25 - Excluded hospital units: Common requirements.

Code of Federal Regulations, 2011 CFR

2011-10-01

... physical facility or because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (c... (ii) Because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (5) For cost...

42 CFR 412.25 - Excluded hospital units: Common requirements.

Code of Federal Regulations, 2014 CFR

2014-10-01

... physical facility or because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (c... (ii) Because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (5) For cost...

42 CFR 412.25 - Excluded hospital units: Common requirements.

Code of Federal Regulations, 2012 CFR

2012-10-01

... physical facility or because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (c... (ii) Because of catastrophic events such as fires, floods, earthquakes, or tornadoes. (5) For cost...

Planning for Tornados.

ERIC Educational Resources Information Center

Napier, Erv; Pritchard, Janet

1981-01-01

Tornadoes are a very real threat to many schools. Planners should be aware of a number of design and construction considerations that will help to insure safe spaces for school children and other occupants. (Author/MLF)

Coupling of ionosphere and troposphere during the occurrence of isolated tornadoes on November 20, 1973

NASA Technical Reports Server (NTRS)

Hung, R. J.; Phan, T.; Smith, R. E.

1979-01-01

The paper examines the coupling between the ionosphere and the troposphere during time periods with isolated tornadoes on the stormy day of November 20, 1973. Observations are made with a high-frequency CW Doppler array system, in which radio receivers located at a central site monitored signals transmitted from three independent remote sites on three sets of frequencies (4.0125, 4.759, 5.734 MHz) and reflected off the ionosphere approximately halfway between the transmitter and receiver sites. It is shown that the sources of the gravity waves associated with tornadoes are always on the squall lines and near the tornado touchdown locations, and that analyses of ionospheric Doppler sounder observations of medium-scale gravity waves can contribute to the understanding of the coupling between the ionosphere and the troposphere during periods of severe storm activity.

Tornado Damage Assessment: Reconstructing the Wind Through Debris Tracking and Treefall Pattern Analysis

NASA Astrophysics Data System (ADS)

Godfrey, C. M.; Peterson, C. J.; Lombardo, F.

2017-12-01

Efforts to enhance the resilience of communities to tornadoes requires an understanding of the interconnected nature of debris and damage propagation in both the built and natural environment. A first step toward characterizing the interconnectedness of these elements within a given community involves detailed post-event surveys of tornado damage. Such damage surveys immediately followed the 22 January 2017 EF3 tornadoes in the southern Georgia towns of Nashville and Albany. After assigning EF-scale ratings to impacted structures, the authors geotagged hundreds of pieces of debris scattered around selected residential structures and outbuildings in each neighborhood and paired each piece of debris with its source structure. Detailed information on trees in the vicinity of the structures supplements the debris data, including the species, dimensions, location, fall direction, and level of damage. High-resolution satellite imagery helps to identify the location and fall direction of hundreds of additional forest trees. These debris and treefall patterns allow an estimation of the near-surface wind field using a Rankine vortex model coupled with both a tree stability model and an infrastructure fragility model that simulates debris flight. Comparisons between the modeled damage and the actual treefall and debris field show remarkable similarities for a selected set of vortex parameters, indicating the viability of this approach for estimating enhanced Fujita scale levels, determining the near-surface wind field of a tornado during its passage through a neighborhood, and identifying how debris may contribute to the overall risk from tornadoes.

The effects of the April 2011 tornado outbreak on personal preparedness in Jefferson County, Alabama.

PubMed

McCormick, Lisa C; Pevear, Jesse; Rucks, Andrew C; Ginter, Peter M

2014-01-01

The purpose of this study was to examine the effects of a tornado disaster on the personal preparedness of local residents to determine (1) to what extent the tornado outbreak experience had altered preparedness awareness, willingness to act, and levels of personal preparedness of residents as measured by possession of a preparedness kit; and (2) what effect this experience had on the variables associated with having a complete disaster preparedness kit. Two random digit-dialed surveys were completed following the Behavioral Risk Factor Surveillance System protocols. The pre-tornado survey was conducted between October and December 2010 and the post-tornado survey was conducted between January and March 2012. After the April 2011 tornado outbreak, 86.08% of the respondents (n = 1364) reported that they had thought more about personal or family preparedness and 59.65% (n = 907) reported that they had taken actions to increase their level of preparedness. Overall, general awareness of preparedness media campaigns increased significantly (almost 24%; P < .0001), as did the percentage of those having a complete disaster preparedness kit (a 66% increase, not quite doubled from 2010 to 2012; P < .0001). Findings of the study indicate that the disaster had a significant impact on the local residents' (1) awareness of preparedness campaigns, (2) awareness of the need to be prepared, (3) willingness to become better prepared, and (4) possession of a disaster and emergency preparedness kit and its associated items.

Millimeter-wave molecular line observations of the Tornado nebula

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sakai, D.; Oka, T.; Tanaka, K.

We report the results of millimeter-wave molecular line observations of the Tornado Nebula (G357.7-0.1), which is a bright radio source behind the Galactic center region. A 15' × 15' area was mapped in the J = 1-0 lines of CO, {sup 13}CO, and HCO{sup +} with the Nobeyama Radio Observatory 45 m telescope. The Very Large Array archival data of OH at 1720 MHz were also reanalyzed. We found two molecular clouds with separate velocities, V{sub LSR} = –14 km s{sup –1} and +5 km s{sup –1}. These clouds show rough spatial anti-correlation. Both clouds are associated with OH 1720more » MHz emissions in the area overlapping with the Tornado Nebula. The spatial and velocity coincidence indicates violent interaction between the clouds and the Tornado Nebula. Modestly excited gas prefers the position of the Tornado 'head' in the –14 km s{sup –1} cloud, also suggesting the interaction. Virial analysis shows that the +5 km s{sup –1} cloud is more tightly bound by self-gravity than the –14 km s{sup –1} cloud. We propose a formation scenario for the Tornado Nebula; the +5 km s{sup –1} cloud collided into the –14 km s{sup –1} cloud, generating a high-density layer behind the shock front, which activates a putative compact object by Bondi-Hoyle-Lyttleton accretion to eject a pair of bipolar jets.« less

Magnetohydrodynamic Models of Molecular Tornadoes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Au, Kelvin; Fiege, Jason D., E-mail: fiege@physics.umanitoba.ca

Recent observations near the Galactic Center (GC) have found several molecular filaments displaying striking helically wound morphology that are collectively known as molecular tornadoes. We investigate the equilibrium structure of these molecular tornadoes by formulating a magnetohydrodynamic model of a rotating, helically magnetized filament. A special analytical solution is derived where centrifugal forces balance exactly with toroidal magnetic stress. From the physics of torsional Alfvén waves we derive a constraint that links the toroidal flux-to-mass ratio and the pitch angle of the helical field to the rotation laws, which we find to be an important component in describing the molecularmore » tornado structure. The models are compared to the Ostriker solution for isothermal, nonmagnetic, nonrotating filaments. We find that neither the analytic model nor the Alfvén wave model suffer from the unphysical density inversions noted by other authors. A Monte Carlo exploration of our parameter space is constrained by observational measurements of the Pigtail Molecular Cloud, the Double Helix Nebula, and the GC Molecular Tornado. Observable properties such as the velocity dispersion, filament radius, linear mass, and surface pressure can be used to derive three dimensionless constraints for our dimensionless models of these three objects. A virial analysis of these constrained models is studied for these three molecular tornadoes. We find that self-gravity is relatively unimportant, whereas magnetic fields and external pressure play a dominant role in the confinement and equilibrium radial structure of these objects.« less

Study of the tornado event in Greece on March 25, 2009: Synoptic analysis and numerical modeling using modified topography

NASA Astrophysics Data System (ADS)

Matsangouras, I. T.; Nastos, P. T.; Pytharoulis, I.

2016-03-01

Recent research revealed that western Greece and NW Peloponnese are regions that favor prefrontal tornadic incidence. On March 25, 2009 a tornado developed approximately at 10:30 UTC near Varda village (NW Peloponnese). Tornado intensity was T4-T5 (TORRO scale) and consequently caused an economic impact of 350,000 € over the local society. The goals of this study are: (i) to analyze synoptic and remote sensing features regarding the tornado event over NW Peloponnese and (ii) to investigate the role of topography in tornadogenesis triggered under strong synoptic scale forcing over that area. Synoptic analysis was based on the European Centre for Medium-Range Weather Forecasts (ECMWF) data sets. The analysis of daily anomaly of synoptic conditions with respect to 30 years' climatology (1981-2010), was based on the National Centers for Environmental Prediction-National Center for Atmospheric Research (NCEP-NCAR) reanalysis data sets. In addition, numerous remote sensing data sets were derived by the Hellenic National Meteorological Service (HNMS) weather station network in order to better interpret the examined tornado event. Finally, numerical modeling was performed using the non-hydrostatic Weather Research and Forecasting model (WRF), initialized by ECMWF gridded analyses, with telescoping nested grids that allow the representation of atmospheric circulations ranging from the synoptic scale down to the meso-scale. The two numerical experiments were performed on the basis of: (a) the presence and (b) the absence of topography (landscape), so as to determine whether the occurrence of a tornado - identified by diagnostic instability indices - could be indicated by modifying topography. The energy helicity index (EHI), the bulk Richardson number (BRN) shear, the storm-relative environmental helicity (SRH), and the maximum convective available potential energy (MCAPE, for parcels with maximum θe) were considered as principal diagnostic instability variables and employed in both numerical experiments. Furthermore, model verification was conducted, accompanied by analysis of the absolute vorticity budget. Synoptic analysis revealed that the synoptic weather conditions on March 25, 2009 are in agreement with the composite synoptic climatology for tornado days over western Greece. In addition, maximum daily anomalies at the barometric levels of 500, 700, 850 and 925 hPa were found, compared to the climatology of composite mean anomalies for tornado days over western Greece. Numerical simulations revealed that the topography of NW Peloponnese did not constitute an important factor during the tornado event on March 25, 2009, based on EHI, SRH, BRN, and MCAPE analyses.

Ensemble experiments using a nested LETKF system to reproduce intense vortices associated with tornadoes of 6 May 2012 in Japan

NASA Astrophysics Data System (ADS)

Seko, Hiromu; Kunii, Masaru; Yokota, Sho; Tsuyuki, Tadashi; Miyoshi, Takemasa

2015-12-01

Experiments simulating intense vortices associated with tornadoes that occurred on 6 May 2012 on the Kanto Plain, Japan, were performed with a nested local ensemble transform Kalman filter (LETKF) system. Intense vortices were reproduced by downscale experiments with a 12-member ensemble in which the initial conditions were obtained from the nested LETKF system analyses. The downscale experiments successfully generated intense vortices in three regions similar to the observed vortices, whereas only one tornado was reproduced by a deterministic forecast. The intense vorticity of the strongest tornado, which was observed in the southernmost region, was successfully reproduced by 10 of the 12 ensemble members. An examination of the results of the ensemble downscale experiments showed that the duration of intense vorticities tended to be longer when the vertical shear of the horizontal wind was larger and the lower airflow was more humid. Overall, the study results show that ensemble forecasts have the following merits: (1) probabilistic forecasts of the outbreak of intense vortices associated with tornadoes are possible; (2) the miss rate of outbreaks should decrease; and (3) environmental factors favoring outbreaks can be obtained by comparing the multiple possible scenarios of the ensemble forecasts.

SOLAR MAGNETIZED TORNADOES: ROTATIONAL MOTION IN A TORNADO-LIKE PROMINENCE

DOE Office of Scientific and Technical Information (OSTI.GOV)

Su, Yang; Veronig, Astrid; Temmer, Manuela

Su et al. proposed a new explanation for filament formation and eruption, where filament barbs are rotating magnetic structures driven by underlying vortices on the surface. Such structures have been noticed as tornado-like prominences when they appear above the limb. They may play a key role as the source of plasma and twist in filaments. However, no observations have successfully distinguished rotational motion of the magnetic structures in tornado-like prominences from other motions such as oscillation and counter-streaming plasma flows. Here we report evidence of rotational motions in a tornado-like prominence. The spectroscopic observations in two coronal lines were obtainedmore » from a specifically designed Hinode/EIS observing program. The data revealed the existence of both cold and million-degree-hot plasma in the prominence leg, supporting the so-called prominence-corona transition region. The opposite velocities at the two sides of the prominence and their persistent time evolution, together with the periodic motions evident in SDO/AIA dark structures, indicate a rotational motion of both cold and hot plasma with a speed of ∼5 km s{sup –1}.« less

Windfield and trajectory models for tornado-propelled objects. Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Redmann, G.H.; Radbill, J.R.; Marte, J.E.

1983-03-01

This is the final report of a three-phased research project to develop a six-degree-of-freedom mathematical model to predict the trajectories of tornado-propelled objects. The model is based on the meteorological, aerodynamic, and dynamic processes that govern the trajectories of missiles in a tornadic windfield. The aerodynamic coefficients for the postulated missiles were obtained from full-scale wind tunnel tests on a 12-inch pipe and car and from drop tests. Rocket sled tests were run whereby the 12-inch pipe and car were injected into a worst-case tornado windfield in order to verify the trajectory model. To simplify and facilitate the use ofmore » the trajectory model for design applications without having to run the computer program, this report gives the trajectory data for NRC-postulated missiles in tables based on given variables of initial conditions of injection and tornado windfield. Complete descriptions of the tornado windfield and trajectory models are presented. The trajectory model computer program is also included for those desiring to perform trajectory or sensitivity analyses beyond those included in the report or for those wishing to examine other missiles and use other variables.« less

Observational analysis of the interaction between a baroclinic boundary and supercell storms on 27 April 2011

NASA Astrophysics Data System (ADS)

Sherrer, Adam Thomas

A thermal boundary developed during the morning to early afternoon hours on 27 April as a result of rainfall evaporation and shading from reoccurring deep convection. This boundary propagated to the north during the late afternoon to evening hours. The presence of the boundary produced an area more conducive for the formation of strong violent tornadoes through several processes. These processes included the production of horizontally generated baroclinic vorticity, increased values in storm-relative helicity, and decreasing lifting condensation level heights. Five supercell storms formed near and/or propagated alongside this boundary. Supercells that interacted with this boundary typically produced significant tornadic damage over long distances. Two of these supercells formed to the south (warm) side of the boundary and produced a tornado prior to crossing to the north (cool) side of the boundary. These two storms exhibited changes in appearance, intensity, and structure. Two other supercells formed well south of the boundary. These two storms remained relatively weak until they interacted with the boundary. These storms then rapidly intensified and produced tornadoes. Supercells that formed well into the cool side of the boundary either did not produce tornadoes or the tornadoes were determined to be weak in nature.

Potential radiological impact of tornadoes on the safety of Nuclear Fuel Services' West Valley Fuel Reprocessing Plant. Volume I. Tornado effects on head-end cell airflow

DOE Office of Scientific and Technical Information (OSTI.GOV)

Holloway, L.J.; Andrae, R.W.

1981-09-01

This report describes results of a parametric study of the impacts of a tornado-generated depressurization on airflow in the contaminated process cells within the presently inoperative Nuclear Fuel Services fuel reprocessing facility near West Valley, NY. The study involved the following tasks: (1) mathematical modeling of installed ventilation and abnormal exhaust pathways from the cells and prediction of tornado-induced airflows in these pathways; (2) mathematical modeling of individual cell flow characteristics and prediction of in-cell velocities induced by flows from step 1; and (3) evaluation of the results of steps 1 and 2 to determine whether any of the pathwaysmore » investigated have the potential for releasing quantities of radioactively contaminated air from the main process cells. The study has concluded that in the event of a tornado strike, certain pathways from the cells have the potential to release radioactive materials of the atmosphere. Determination of the quantities of radioactive material released from the cells through pathways identified in step 3 is presented in Part II of this report.« less

ARMOR Dual-Polarimetric Radar Observations of Tornadic Debris Signatures

NASA Technical Reports Server (NTRS)

Petersen, W. A,; Carey, L. D.; Knupp, K. R.; Schultz, C.; Johnson, E.

2008-01-01

During the Super-Tuesday tornado outbreak of 5-6 February 2008, two EF-4 tornadoes occurred in Northern Alabama within 75 km range of the University of Alabama in Huntsville (UAH) Advanced Radar for Meteorological and Operational Research (ARMOR, C-band dual-polarimetric). This study will present an analysis of ARMOR radar-indicated dual-polarimetric tornadic debris signatures. The debris signatures were associated with spatially-confined large decreases in the copolar correlation coefficient (rho(hv)hv) that were embedded within broader mesocyclone "hook" signatures. These debris signatures were most obviously manifest during the F-3 to F-4 intensity stages of the tornado(s) and extended to altitudes of approximately 3 km. The rho(hv) signatures of the tornadic debris were the most easily distinguished relative to other polarimetric and radial velocity parameters (e.g., associated with large hail and/or the incipient mesocyclone). Based on our analysis, and consistent with the small number of studies found in the literature, we conclude that dual-polarimetric radar data offer at least the possibility for enhancing specificity and confidence in the process of issuing tornado warnings based only on radar detection of threatening circulation features.

24 CFR 203.379 - Adjustment for damage or neglect.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., or tornado, or, for mortgages insured on or after January 1, 1977, the property has suffered damage..., earthquake, hurricane, or tornado, or if it was damaged notwithstanding reasonable action by the mortgagee as...

24 CFR 203.379 - Adjustment for damage or neglect.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., or tornado, or, for mortgages insured on or after January 1, 1977, the property has suffered damage..., earthquake, hurricane, or tornado, or if it was damaged notwithstanding reasonable action by the mortgagee as...

25 CFR 273.44 - Use and transfer of Government property.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., snow, and tornado in amounts and with companies satisfactory to the Federal officer in charge of the... or tornado, the insurance money collected shall be expended only for repair or replacement of...

24 CFR 203.379 - Adjustment for damage or neglect.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., or tornado, or, for mortgages insured on or after January 1, 1977, the property has suffered damage..., earthquake, hurricane, or tornado, or if it was damaged notwithstanding reasonable action by the mortgagee as...

25 CFR 273.44 - Use and transfer of Government property.

Code of Federal Regulations, 2014 CFR

2014-04-01

..., snow, and tornado in amounts and with companies satisfactory to the Federal officer in charge of the... or tornado, the insurance money collected shall be expended only for repair or replacement of...

24 CFR 203.379 - Adjustment for damage or neglect.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., or tornado, or, for mortgages insured on or after January 1, 1977, the property has suffered damage..., earthquake, hurricane, or tornado, or if it was damaged notwithstanding reasonable action by the mortgagee as...

25 CFR 273.44 - Use and transfer of Government property.

Code of Federal Regulations, 2012 CFR

2012-04-01

..., snow, and tornado in amounts and with companies satisfactory to the Federal officer in charge of the... or tornado, the insurance money collected shall be expended only for repair or replacement of...

25 CFR 273.44 - Use and transfer of Government property.

Code of Federal Regulations, 2010 CFR

2010-04-01

..., snow, and tornado in amounts and with companies satisfactory to the Federal officer in charge of the... or tornado, the insurance money collected shall be expended only for repair or replacement of...

25 CFR 273.44 - Use and transfer of Government property.

Code of Federal Regulations, 2011 CFR

2011-04-01

..., snow, and tornado in amounts and with companies satisfactory to the Federal officer in charge of the... or tornado, the insurance money collected shall be expended only for repair or replacement of...

24 CFR 203.379 - Adjustment for damage or neglect.

Code of Federal Regulations, 2013 CFR

2013-04-01

..., or tornado, or, for mortgages insured on or after January 1, 1977, the property has suffered damage..., earthquake, hurricane, or tornado, or if it was damaged notwithstanding reasonable action by the mortgagee as...

Investigation of air cleaning system response to accident conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrae, R.W.; Bolstad, J.W.; Foster, R.D.

1980-01-01

Air cleaning system response to the stress of accident conditions are being investigated. A program overview and hghlight recent results of our investigation are presented. The program includes both analytical and experimental investigations. Computer codes for predicting effects of tornados, explosions, fires, and material transport are described. The test facilities used to obtain supportive experimental data to define structural integrity and confinement effectiveness of ventilation system components are described. Examples of experimental results for code verification, blower response to tornado transients, and filter response to tornado and explosion transients are reported.

Design of convolutional tornado code

NASA Astrophysics Data System (ADS)

Zhou, Hui; Yang, Yao; Gao, Hongmin; Tan, Lu

2017-09-01

As a linear block code, the traditional tornado (tTN) code is inefficient in burst-erasure environment and its multi-level structure may lead to high encoding/decoding complexity. This paper presents a convolutional tornado (cTN) code which is able to improve the burst-erasure protection capability by applying the convolution property to the tTN code, and reduce computational complexity by abrogating the multi-level structure. The simulation results show that cTN code can provide a better packet loss protection performance with lower computation complexity than tTN code.

The nuclear dynamo; Can a nuclear tornado annihilate nations

DOE Office of Scientific and Technical Information (OSTI.GOV)

McNally, J.R. Jr.

1991-01-01

This paper reports on the development of the hypothesis of a nuclear dynamo for a controlled nuclear fusion reactor. This dynamo hypothesis suggests properties for a nuclear tornado that could annihilate nations if accidentally triggered by a single high yield to weight nuclear weapon detonation. The formerly classified reports on ignition of the atmosphere, the properties of a nuclear dynamo, methods to achieve a nuclear dynamo in the laboratory, and the analogy of a nuclear dynamo to a nuclear tornado are discussed. An unclassified international study of this question is urged.

Hospitalized tornado victims.

PubMed

Harris, L F

1992-01-01

We reviewed the clinical findings of 59 patients admitted to Huntsville's three hospitals during the first 24 hours after the November 15, 1989, tornado and as a result of injury caused by the tornado. Fracture of a bone was the most common injury followed by soft tissue trauma and infection. A variety of non-traumatic conditions also were encountered. Fractures were more frequent above the waist than below and five fractures became infected resulting in osteomyelitis. Infections most often involved the urinary tract and bone and were caused primarily by aerobic gram-negative bacilli. The hospital mortality rate was 7%.

A Renaissance Depiction of a Tornado.

NASA Astrophysics Data System (ADS)

Hoinka, Klaus P.; de Castro, Manuel

2005-04-01

In the Renaissance, impressive weather features inspired considerable interest among artists. The depiction of a tornado and other weather features are discussed that appear on a sixteenth-century series of 12 huge tapestries (“Conquest of Tunis”) woven by the carpet manufacturer Willem de Pannemaker in Brussels, Belgium, between 1549 and 1551. The outstanding depiction of the tornado is presumably the earliest pictorial presentation of a tornado, at least in the Latin west.During the Renaissance, tapestries were an obligatory fixture of a European court and were used as an instrument for political propaganda and dynastic demonstration. The “Conquest of Tunis” tapestries are important pieces of Eu-ropean art commissioned by the Habsburgian emperor Charles V (1500–58), one of the most important ruling personalities in Euro-pean history. In 1535, he undertook a crusade to Tunis, Tunisia, in order to diminish the Ottoman emperor's power in the western Mediterranean region. Charles V wanted to ensure that the expedition would not be forgotten. In order to guarantee this, the emperor took along the Flemish painter Jan Cornelisz Vermeyen who painted sketches that were used as prototypes for the “Conquest of Tunis” tapestries. These present a highly detailed narrative of the expedition to Tunis.The depiction of a tornado, along with heavy rain and a sandstorm, raises the question of why these meteorological features are included in the scene. To the authors' knowledge, no mention is made of them in the art literature (except for the sandstorm, which actually occurred). This is particularly surprising because the tornado, at least, appears so prominently in one of the tapestries. Therefore, the weather features are discussed in terms of their meteorological, decorative, and symbolic importance. The tornado and the heavy rain seem to have been rendered in order to emphasize symbolically the beginning and ending of the military campaign. Although these weather elements are depicted naturalistically, they are portrayed not for their own sake, but to support the related historical event in an emblematic manner.

7 CFR 457.107 - Florida citrus fruit crop insurance provisions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... grove; (2) Freeze; (3) Hail; (4) Hurricane; (5) Tornado; (6) Excess wind, but only if it causes the... hurricane, tornado or other excess wind storms that results in the fruit not meeting the standards for...

Reduction and analysis of data collected during the electromagnetic tornado experiment

NASA Technical Reports Server (NTRS)

Davisson, L. D.; Bradbury, J.

1975-01-01

Progress is reviewed on the reduction and analysis of tornado data collected on analog tape. The strip chart recording of 7 tracks from all available analog data for quick look analysis is emphasized.

7 CFR 457.107 - Florida citrus fruit crop insurance provisions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... grove; (2) Freeze; (3) Hail; (4) Hurricane; (5) Tornado; (6) Excess wind, but only if it causes the... hurricane, tornado or other excess wind storms that results in the fruit not meeting the standards for...

7 CFR 457.107 - Florida citrus fruit crop insurance provisions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... grove; (2) Freeze; (3) Hail; (4) Hurricane; (5) Tornado; (6) Excess wind, but only if it causes the... hurricane, tornado or other excess wind storms that results in the fruit not meeting the standards for...

7 CFR 457.107 - Florida citrus fruit crop insurance provisions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... grove; (2) Freeze; (3) Hail; (4) Hurricane; (5) Tornado; (6) Excess wind, but only if it causes the... hurricane, tornado or other excess wind storms that results in the fruit not meeting the standards for...

Permanent record. Electronic records aid in the aftermath of Joplin tornado.

PubMed

Russell, Matthew

2011-09-01

When a tornado struck St. John's Regional Medical Center in May 2011, its patient records were stored in a newly launched electronic health record system, helping prevent a bad situation from being worse.

Tornadoes and Other Big Winds.

ERIC Educational Resources Information Center

Markle, Sandra

1983-01-01

Information is presented for teaching about the formation of tornadoes and their effects. Ideas for relevant class discussion topics, writing assignments, and experiments to illustrate how temperature and air pressure changes involved in the storms work are also given. (PP)

Analysis of changes in tornadogenesis conditions over Northern Eurasia based on a simple index of atmospheric convective instability

NASA Astrophysics Data System (ADS)

Chernokulsky, A. V.; Kurgansky, M. V.; Mokhov, I. I.

2017-12-01

A simple index of convective instability (3D-index) is used for analysis of weather and climate processes that favor to the occurrence of severe convective events including tornadoes. The index is based on information on the surface air temperature and humidity. The prognostic ability of the index to reproduce severe convective events (thunderstorms, showers, tornadoes) is analyzed. It is shown that most tornadoes in North Eurasia are characterized by high values of the 3D-index; furthermore, the 3D-index is significantly correlated with the available convective potential energy. Reanalysis data (for recent decades) and global climate model simulations (for the 21st century) show an increase in the frequency of occurrence of favorable for tornado formation meteorological conditions in the regions of Northern Eurasia. The most significant increase is found on the Black Sea coast and in the south of the Far East.

Calculation of wind speeds required to damage or destroy buildings

NASA Astrophysics Data System (ADS)

Liu, Henry

Determination of wind speeds required to damage or destroy a building is important not only for the improvement of building design and construction but also for the estimation of wind speeds in tornadoes and other damaging storms. For instance, since 1973 the U.S. National Weather Service has been using the well-known Fujita scale (F scale) to estimate the maximum wind speeds of tornadoes [Fujita, 1981]. The F scale classifies tornadoes into 13 numbers, F-0 through F-12. The wind speed (maximum gust speed) associated with each F number is given in Table 1. Note that F-6 through F-12 are for wind speeds between 319 mi/hr (mph) and the sonic velocity (approximately 760 mph; 1 mph = 1.6 km/kr). However, since no tornadoes have been classified to exceed F-5, the F-6 through F-12 categories have no practical meaning [Fujita, 1981].

The effects of new media for emergency tornado notification on the digital divide

NASA Astrophysics Data System (ADS)

Meyers, Stephanie

This study explored the possible continued existence of a digital divide as it related to how residents in two disperse communities received notification of late season tornado events in 2013. The theoretical perspective of the Diffusion of Innovations, Knowledge Gap and Structuration theories were used to examine how notifications were received based on socioeconomic indicators of total household income and education affected the ability for respondents to be notified of the impending danger. Results varied for the communities surveyed, both supporting and negating how specific socioeconomic factors influence how respondents received notifications and the behavior they took after the message was received. Findings of the study indicate that higher total household income and higher education are often times associated with how respondents receive warnings of tornadoes in their area, but associations are not always consistent. Findings of this study show differences in how each community receives and reacts to tornado warnings.

Case study of the operational usefulness of the Sharp Workstation in forecasting a mesocyclone-induced cold sector Tornado event in California. Technical memo

DOE Office of Scientific and Technical Information (OSTI.GOV)

Monteverdi, J.P.

1993-03-01

An illustration of the operational usefulness of the SHARP Workstation in providing supplementary guidance to forecasters in a situation in which two tornadoes occurred in California's Sacramento Valley is presented. Use of the SHARP Workstation in analyzing the initial hodograph and in producing a bogus afternoon sounding and hodograph for the Sacramento Valley indicated that buoyancy and shear were in the correct range for moderate to strong mesocyclone-induced tornadoes. Conventional wisdom would have suggested that weak funnel clouds and small hail were the chief threats in the weather pattern. However, forecasters, aware of the role of shear in inducing stormmore » rotation and of the potential for the weather pattern to be associated with favorable buoyancy and shear parameters in certain regions of California, would have been alert to the possibility of damaging and potentially life-threatening tornadoes.« less

Satellite-observed cloud-top height changes in tornadic thunderstorms

NASA Technical Reports Server (NTRS)

Adler, R. F.; Fenn, D. D.

1981-01-01

Eleven tornadic storms are evaluated with respect to cloud top temperature changes relative to tornado touchdown. Digital IR data from the SMS/GOES geosynchronous satellites were employed for 10 F2 and one F1 tornadoes. A rapid ascent of the cloud tops 30-45 min before tornado touchdown, a temperature decrease of 0.4 K/min, and an ascent rate of about 3 m/sec were observed. The presence of an operating Doppler radar for three of the sample storms allowed detection of a mesocyclone coincident with the rapid cloud top ascent. The intensification and descent of the vortex to form a tornado is concluded to be due to a weakening of the updraft, the formation of a downdraft, and a shift of the vortex to the updraft-downdraft boundary, leading to dominance of the tilting term in the generation of vorticity.

Laboratory Study of Topographic Effects on the Near-surface Tornado Flow Field

NASA Astrophysics Data System (ADS)

Razavi, Alireza; Sarkar, Partha P.

2018-03-01

To study topographic effects on the near-surface tornado flow field, the Iowa State University tornado simulator was used to simulate a translating tornado passing over three different two-dimensional topographies: a ridge, an escarpment and a valley. The effect of the translation speed on maximum horizontal wind speeds is observed for translation speeds of 0.15 and 0.50 m s^{-1} , with the lower value resulting in a larger maximum horizontal wind speed. The tornado translation over the three topographies with respect to flat terrain is assessed for changes in: (a) the maximum horizontal wind speeds in terms of the flow-amplification factor; (b) the maximum aerodynamic drag in terms of the tornado speed-up ratio; (c) the maximum duration of exposure at any location to high wind speeds of a specific range in terms of the exposure amplification factor. Results show that both the maximum wind amplification factor of 14%, as well as the maximum speed-up ratio of 14%, occur on the ridge. For all topographies, the increase in aerodynamic drag is observed to be maximized for low-rise buildings, which illustrates the importance of the vertical profiles of the horizontal wind speed near the ground. The maximum exposure amplification factors, estimated for the range of wind speeds corresponding to the EF2 (50-60 m s^{-1} ) and EF3 (61-75 m s^{-1}) scales, are 86 and 110% for the ridge, 4 and 60% for the escarpment and - 6 and 47% for the valley, respectively.

Number of warning information sources and decision making during tornadoes.

PubMed

Luo, Jianjun; Cong, Zhen; Liang, Daan

2015-03-01

Taking proper protective action upon receiving tornado warnings is critical to reducing casualties. With more warning information sources becoming available, how the number of such information sources affects decision making should be quantitatively investigated. To examine how the number of warning information sources affected individuals' decisions to take protective action during tornadoes. A telephone survey using random sampling was conducted in 2012 with residents in Tuscaloosa AL and Joplin MO, resulting in a working sample of 782 respondents. Both cities were struck by violent tornadoes (Enhanced Fujita Scale [EF]4 and EF5) in 2011. The analysis was conducted in 2013. Logistic regression analysis showed that relative to having only one warning information source, having two and three or more warning information sources significantly increased the odds of taking protective action in Joplin but not in Tuscaloosa; having three or more sources had a significantly stronger effect on taking protective action in Joplin than in Tuscaloosa. Having an emergency preparation plan in both cities and being white in Tuscaloosa significantly increased the odds of taking protective action, whereas being divorced in Joplin reduced these odds. Receiving warnings from more warning information sources might be more beneficial in places with less previous exposure to tornadoes and for populations with lower awareness of a potential tornado and higher probability of receiving no warnings. Emergency management agencies and public health officials should give priority to these places and populations when formulating disaster mitigation decisions and policies. Copyright © 2015 American Journal of Preventive Medicine. Published by Elsevier Inc. All rights reserved.

Assessing American Red Cross First Aid mobile app user trends: Implications for resilience.

PubMed

Musigdilok, Visanee V; Demeter, Natalie E; Burke, Rita V; Shook, Eric; Ajayakumar, Jayakrishnan; Berg, Bridget M; Hawkins, Michelle D; Ferree, John; MacAloney, Brenton W; Chung, Sarita; Pellegrino, Jeffrey L; Tolli, Dominick; Hansen, Grant; Upperman, Jeffrey S

2015-01-01

Disasters have devastated communities, impacted the economy, and resulted in a significant increase in injuries. As the use of mobile technology increasingly becomes a common aspect of everyday life, it is important to understand how it can be used as a resource. The authors examined the use of American Red Cross mobile apps and aimed to characterize user trends to better understand how mobile apps can help bolster individual and community preparedness, resilience, and response efforts. Tornado data were obtained from the National Oceanic and Atmospheric Administration and the National Weather Service. Data for the mobile apps were provided by the American Red Cross. All data were reviewed for 2013, 2014, and three specific tornado events. Data were organized in Microsoft Excel spreadsheets and then graphed or mapped using ArcMap 10.2(™). Between 2013 and 2014, 1,068 tornado watches and 3,682 tornado warnings were issued. Additionally, 37,957,560 Tornado app users and 1,289,676 First Aid app users were active from 2013 to 2014. Overall, there was an increase in the use of American Red Cross mobile apps during tornado occurrences. Yet the increase does not show a consistent correlation with the number of watches and warnings issued. Mobile apps can be a resourceful tool. This study shows that mobile app use increases during a disaster. The findings indicate that there is potential to use mobile apps for building resilience as the apps provide information to support individuals and communities in helping before, during, and after disasters.

Numerical modeling analysis of the mesoscale environment conducive to two tornado events using the COSMO.Gr model over Greece

NASA Astrophysics Data System (ADS)

Avgoustoglou, E.; Matsangouras, I. T.; Pytharoulis, I.; Kamperakis, N.; Mylonas, M.; Nastos, P. T.; Bluestein, H. W.

2018-08-01

The COnsortium for Small-scale MOdeling (COSMO) was formed in October 1998, and its general goal is to develop, improve and maintain a non-hydrostatic limited-area atmospheric model. The COSMO model has been designed both for operational numerical weather prediction (NWP) as well as various scientific applications on the meso-β and meso-γ scale. Two tornado case studies were selected to investigate the ability of COSMO model to depict the characteristics of severe convective weather, which favoured the development of the associated storms. The first tornado (TR01) occurred, close to Ag. Ilias village, 8 Km north-western of Aitoliko city over western Greece on February 7, 2013, while the second tornado (TR02) was developed close to Palio Katramio village, 8 Km southern from Xanthi city over northern Greece on November 25, 2015. Although both tornadoes had a short lifetime, they caused significant damages. The COSMO.GR atmospheric model was initialized with analysis from the European Centre for Medium-Range Weather Forecasts (ECMWF). The resulting numerical products with spatial resolution of 0.02° (∼ 2 km) over the geographical domain of Greece depicted very well the severe convective conditions close to tornadoes formation. The Energy Helicity Index (EHI) diagnostic variable in both numerical simulations showed a gradual increase of values closing to the location and time of the tornadogenesis. Similar to EHI, the storm relative helicity (SRH) spatio-temporal analysis followed a gradual increase prior to the tornadogenesis events and was reduced after them.

Weather Safety: Making Emergency Preparations.

ERIC Educational Resources Information Center

Lobe, Bill

1997-01-01

Precautions to take before, what to do if outdoors or indoors during, and inspecting for damage after thunderstorms, tornadoes, hurricanes, and floods. Sidebars discuss emergency supplies to keep on hand, calculating distance from thunderstorms, and the Fujita tornado rating scale. (TD)

26 CFR 1.9300-1 - Reduction in taxable income for housing displaced individuals.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Emergency Assistance Act (42 U.S.C. 5170) (Stafford Act) by reason of severe storms, tornados, or flooding... attributable to the severe storms, tornados, or flooding in the Midwestern disaster area. (g) Examples. The...

26 CFR 1.9300-1 - Reduction in taxable income for housing displaced individuals.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Emergency Assistance Act (42 U.S.C. 5170) (Stafford Act) by reason of severe storms, tornados, or flooding... attributable to the severe storms, tornados, or flooding in the Midwestern disaster area. (g) Examples. The...

26 CFR 1.9300-1 - Reduction in taxable income for housing displaced individuals.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Emergency Assistance Act (42 U.S.C. 5170) (Stafford Act) by reason of severe storms, tornados, or flooding... attributable to the severe storms, tornados, or flooding in the Midwestern disaster area. (g) Examples. The...

26 CFR 1.9300-1 - Reduction in taxable income for housing displaced individuals.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Emergency Assistance Act (42 U.S.C. 5170) (Stafford Act) by reason of severe storms, tornados, or flooding... attributable to the severe storms, tornados, or flooding in the Midwestern disaster area. (g) Examples. The...

26 CFR 1.9300-1 - Reduction in taxable income for housing displaced individuals.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Emergency Assistance Act (42 U.S.C. 5170) (Stafford Act) by reason of severe storms, tornados, or flooding... attributable to the severe storms, tornados, or flooding in the Midwestern disaster area. (g) Examples. The...

NASA Spacecraft Captures Swath of Destruction from Deadly Oklahoma Tornado

NASA Image and Video Library

2013-06-05

The Newcastle-Moore EF-5 tornado ripped through central Oklahoma on May 20, 2013, killing 24 people and leaving behind more than billion in damage. This image was acquired NASA Terra spacecraft on June 2, 2013.

Assessment of Structural Resistance of building 4862 to Earthquake and Tornado Forces [SEC 1 and 2

DOE Office of Scientific and Technical Information (OSTI.GOV)

METCALF, I.L.

1999-12-06

This report presents the results of work done for Hanford Engineering Laboratory under contract Y213-544-12662. LATA performed an assessment of building 4862 resistance to earthquake and tornado forces.

NOAA awards $5.7 million to improve hazardous weather forecasts

Science.gov Websites

tornado prediction. This photo shows a tornado, which struck Smith, Jasper and Clarke Counties in Smith, Jasper and Clarke Counties in Mississippi, and Choctaw County in Alabama on April 27, 2011 during

a Numerical Simulation of a Tornado-Scale Vortex in a Three-Dimensional Cloud Model

NASA Astrophysics Data System (ADS)

Wicker, Louis John

1990-01-01

One of the more spectacular and elusive events of nature is the tornado. Usually spawned by a highly organized, lasting, and rotating thunderstorm called a "supercell", tornadoes are one of the most destructive atmospheric phenomena. Tornadoes almost always have length and time scales smaller than the measurable scales within the observing network of surface stations, conventional radar, Doppler radar and satellites. Therefore direct observations of tornadoes and their parent features are rarely obtained. Consequently, understanding of these phenomena will generally have to come from theoretical work, laboratory experiments, and numerical simulations. In this thesis we seek to understand the process of tornadogenesis within the context of a fully three-dimensional cloud model. Very high horizontal and vertical resolution is used to capture a developing tornado-scale vortex during the simulation of a strongly rotating supercell storm simulated within the 3 April 1964 environment from Witchita Fall, Texas. To better represent the influence of surface friction on the vortex flow, a simple surface layer parametrization of the vertical fluxes of horizontal momentum is added to the model. Results from the simulation show that a tornado -scale vortex forms along the western edge of the mesocyclone, intensifies and rotates cyclonically around the center of the mesocyclone over a several minute period. The inclusion of the surface layer parameterization increases the low -level velocity convergence. Surface vertical vorticity is greater than 0.43 s^{-1} for thirty seconds and greater than 0.3 s^ {-1} for several minutes. During tornadogenesis, pressures at the surface fall 3-4 mb in thirty seconds and a pressure gradient develops of over 7 mb from the outer edge of the tornado to the center. A vortex tube extends from the surface to over 2.5 km aloft and tilts to the northwest. Analyses show that tornadogenesis occurs when the vertical velocity gradients along the western side of the mesocyclone increase and that the principle mechanism for intensifying the vertical vorticity is convergence. Analyses also show that the development of the occlusion updraft along the western edge of the mesocyclone is related to advection of warm air southwestward over the gust front and the lowering of pressure aloft within the mesocyclone core.

Creativity...The Flowering Tornado, Art by Ginny Ruffner.

ERIC Educational Resources Information Center

Johnson, Mark M.

2003-01-01

Presents background information on the artist Ginny Ruffner who was a "flameworker." Includes information on the exhibition entitled "Creativity: The Flowering Tornado, Art by Ginny Ruffner" and the accompanying art pop-up book. Provides photographs of some of her artwork. (CMK)

Exploratory Modeling: Extracting Causality From Complexity

NASA Astrophysics Data System (ADS)

Larsen, Laurel; Thomas, Chris; Eppinga, Maarten; Coulthard, Tom

2014-08-01

On 22 May 2011 a massive tornado tore through Joplin, Mo., killing 158 people. With winds blowing faster than 200 miles per hour, the tornado was the most deadly in the United States since modern record keeping began in the 1950s.

Electric field at the ground in a large tornado

NASA Astrophysics Data System (ADS)

Winn, W. P.; Hunyady, S. J.; Aulich, G. D.

2000-08-01

A number of observers have reported lightning, diffuse luminosity, or other manifestations of electrical activity in tornadoes. To try to quantify these observations, eight instruments with sensors for electric field and other parameters were placed in front of a large tornado that passed by Allison, Texas, on June 8, 1995. The edge of the tornado vortex passed over two of the instruments and near other instruments. When the two instruments were in the low-pressure region near the edge of the vortex, they indicated electric field amplitudes less than about 3 kV/m, which is low compared with amplitudes of 10 kV/m or greater that are often present below thunderclouds. The thunderstorm produced frequent lightning, but there is no evidence from the measurements or from visual observations of lightning in the vortex. However, there was one interesting electrical effect associated with the tornado: the electric field at the two instruments in the vortex relaxed to zero quickly after lightning flashes, whereas the electric field at nearby instruments outside the vortex did not relax quickly after the same lightning flashes. The most likely cause of the rapid relaxation is shielding of the electric field at the ground by charge induced on soil, leaves, grass, and other debris lofted by the strong winds.

Electrical characteristics of simulated tornadoes

NASA Astrophysics Data System (ADS)

Zimmerman, M. I.; Farrell, W. M.; Barth, E. L.; Lewellen, D. C.; Lewellen, W. S.; Perlongo, N. J.; Jackson, T.

2012-12-01

It is well known that tornadoes and dust devils have the ability to accumulate significant, visible clouds of debris. Collisions between sand-like debris species produce different electric charges on different types of grains, which convect along different trajectories around the vortex. Thus, significant charge separations and electric currents are possible, which as the vortex fluctuates over time are thought to produce ULF radiation signatures that have been measured in the field. These electric and magnetic fields may contain valuable information about tornado structure and genesis, and may be critical in driving electrochemical processes within dust devils on Mars. In the present work, existing large eddy simulations of debris-laden tornadoes performed at West Virginia University are coupled with a new debris-charging and advection code developed at Goddard Space Flight Center to investigate the detailed (meter-resolution) fluid-dynamic origins of electromagnetic fields within terrestrial vortices. First results are presented, including simulations of the electric and magnetic fields that would be observed by a near-surface, instrument-laden probe during a direct encounter with a tornado. This research was supported by an appointment to the NASA Postdoctoral Program at the Goddard Space Flight Center, administered by Oak Ridge Associated Universities through a contract with NASA. The generous allocation of computing resources by Dr. Timothy J. Stubbs is gratefully acknowledged.

Influence of the El Niño/Southern Oscillation on tornado and hail frequency in the United States

NASA Astrophysics Data System (ADS)

Allen, John T.; Tippett, Michael K.; Sobel, Adam H.

2015-04-01

The El Niño/Southern Oscillation (ENSO) is characterized by changes in sea surface temperature (SST) and atmospheric convection in the tropical Pacific, and modulates global weather and climate. The phase of ENSO influences United States (US) temperature and precipitation and has long been hypothesized to influence severe thunderstorm occurrence over the US. However, limitations of the severe thunderstorm observational record, combined with large year-to-year variability, have made it difficult to demonstrate an ENSO influence during the peak spring season. Here we use environmental indices that are correlated with tornado and hail activity, and show that ENSO modulates tornado and hail occurrence during the winter and spring by altering the large-scale environment. We show that fewer tornadoes and hail events occur over the central US during El Niño and conversely more occur during La Niña conditions. Moreover, winter ENSO conditions often persist into early spring, and consequently the winter ENSO state can be used to predict changes in tornado and hail frequency during the following spring. Combined with our current ability to predict ENSO several months in advance, our findings provide a basis for long-range seasonal prediction of severe thunderstorm activity.

Two-phase flows in the formed tornado funnel

NASA Astrophysics Data System (ADS)

Sinkevich, O. A.; Bortsova, A. A.

2017-10-01

At present, it is obvious that the problem of the tornado is important not only for our planetЮ to determine the conditions for the formation of a tornado, it is required to take into account a number of hydrodynamic and plasma processes [1 - 6]. Along to prediction of a tornado generation conditions [1 - 3] it is necessary to evaluate the characteristics of its quasi-stationary motion in a formed funnel: the mass of the moving moist air involved in the funnel and the size and form of the funnel. For a complete description of the phenomena, it is necessary to involve numerical calculations. We note that even for numerical calculations using powerful computers, the problem is very difficult because of the need to calculate multiphase turbulent flows with free, self-organizing boundaries [1, 6]. However, “strict” numerical calculations, it is impossible to do without the use of many, often mutually exclusive, models. For example, how to choice an adequate model of turbulence (algebraic, k-ε model, etc.) or the use of additional, often not accepted, hypotheses about certain processes used in calculations (mechanisms on the nature of moisture condensation, etc.). Therefore, along with numerical calculations of such flows, modeling problems that allow an exact solution and allow to determine the most important and observed characteristics of a tornado.

Massive pediatric neurosurgical injuries and lessons learned following a tornado disaster in Alabama.

PubMed

Chern, Joshua J; Miller, Joseph H; Tubbs, R Shane; Whisenhunt, Thomas R; Johnston, James M; Wellons, John C; Rozzelle, Curtis J; Blount, Jeffrey P; Oakes, W Jerry

2011-12-01

A large volume of patients presented to a Level I pediatric trauma center during and after a recent tornado disaster. Injuries of the central and peripheral nervous systems and the medical responses of a pediatric neurosurgical team are reviewed. The clinical courses of patients who suffered cranial, spinal, and peripheral nerve injuries due to the tornado storm are reported. The clinical actions taken by the neurosurgical team during and after the event are reviewed and the lessons learned are discussed. The tornado storm system moved through the Tuscaloosa and Birmingham metropolitan areas on the early evening hours of April 27, 2011. Twenty-four patients received care from the neurosurgical team. A total of 11 cranial (including placement of an external ventricular drain), 2 spine, and 2 peripheral procedures were performed for the victims. Nine procedures were performed within the first 12 hours of the event, and an additional 6 surgeries were performed in the following 24 hours. Injuries of the peripheral nervous system often presented in a delayed fashion. Several key components were identified that enabled adequate neurosurgical care for a large influx of acute patients. Massive casualties due to tornados are rare. A well-organized physician team working with the hospital administration may decrease the mortality and morbidity of such events.

Prominence and tornado dynamics observed with IRIS and THEMIS

NASA Astrophysics Data System (ADS)

Schmieder, Brigitte; Levens, Peter; Labrosse, Nicolas; Mein, Pierre; Lopez Ariste, Arturo; Zapior, Maciek

2017-08-01

Several prominences were observed during campaigns in September 2013 and July 2014 with the IRIS spectrometer and the vector magnetograph THEMIS (Tenerife). SDO/AIA and IRIS provided images and spectra of prominences and tornadoes corresponding to different physical conditions of the transition region between the cool plasma and the corona. The vector magnetic field was derived from THEMIS observations by using the He D3 depolarisation due to the magnetic field. The inversion code (PCA) takes into account the Hanle and Zeeman effects and allows us to compute the strength and the inclination of the magnetic field which is shown to be mostly horizontal in prominences as well as in tornadoes. Movies from SDO/AIA in 304 A and Hinode/SOT in Ca II show the highly dynamic nature of the fine structures. From spectra in Mg II and Si IV lines provided by IRIS and H-alpha observed by the Multi-channel Subtractive Double Pass (MSDP) spectrograph in the Meudon Solar Tower we derived the Doppler shifts of the fine structures and reconstructed the 3D structure of tornadoes. We conclude that the apparent rotation of AIA tornadoes is due to large-scale quasi-periodic oscillations of the plasma along more or less horizontal magnetic structures.

A long-lived tornado on 7 December 2010 in mainland Portugal

NASA Astrophysics Data System (ADS)

Belo-Pereira, Margarida; Andrade, Cristina; Pinto, Paulo

2017-03-01

On 7 December 2010 a long lived convective storm formed southwest of Lisbon in an instability line that developed in a very moist and unstable airmass, in the circulation of an extra-tropical cyclone propagating north-eastwards. This storm crossed the Lisbon district and spawned an F3 tornado a few dozens of kilometers to the northeast. Several parameters evaluating buoyancy, available moisture and vertical wind shear, were derived from Lisbon rawinsonde and ECMWF analyses, highlighting an environment that is favourable for tornadic development. The tornado touchdown occurred by 14:15 UTC, lasting for about 45 min and producing an exceptionally long damage path of around 54 km, according to the damage survey. It caused about 18 million Euros damage, > 40 injured people, but no fatalities. This storm had a very long lifetime of at least 5 h, intensified inland, sustained strong updrafts during, at least, 1 h and hold large hail cores as observed on radar. Exhibiting several supercell like features, it also produced intense lightning, with a predominance of cloud-to-ground flashes before the tornado touchdown and intra-cloud flashes during the tornado lifetime. Furthermore, in high resolution visible satellite imagery, a pattern of feeder clouds was identified one hour before tornadogenesis. This pattern has been associated to storm intensification and the onset of severe weather.

Hurricanes, Storms, and Tornadoes: Geographic Characteristics and Geological Activity

NASA Astrophysics Data System (ADS)

Cadet, D. L.

This book is very disappointing. From the presentation the potential reader might expect to obtain a clear view of the origin of hurricanes, storms, and tornados. Except for some aspects, such as the effect of these phenomena on geological activity, for which some interesting ideas are discussed, the book is a long catalog of destructive weather systems and just describes the different aspects of the phenomena without physical explanations. For example, in the part discussing tornados, it looks like the author put together newspaper clips from some county in Oklahoma, except that the collection is worldwide. The interest lies, maybe, in the large number of illustrations: some of them are reproductions of paintings and drawings dating from the last century. A large number of events are thoroughly described. Another interesting part is the description of tornados that affected the Soviet Union and Europe. Throughout the book there is a large number of duplicate material. Some words are misused: for example, sandstorms originating in the Sahara desert and crossing the Mediterranean Sea are often called hurricanes. A tornado that hit Moscow in May 1937 is referred to as a hurricane. In defense of the author, it must be noted that the book was written in 1969 and only translated in 1983. Another title would be more appropriate.

Tornado injuries related to housing in the Plainfield tornado.

PubMed

Brenner, S A; Noji, E K

1995-02-01

On 28 August 1990, a tornado in Will County, Illinois, caused 29 deaths and more than US $200 million in damage. Risk factors for impact-related morbidity and mortality were studied. A case-control study was conducted of 26 people hospitalized or killed, and 116 injured, randomly selected people who were in houses damaged by the tornado. To obtain information on study subjects, telephone interviews were conducted, and hospital records, coroners' reports, and American Red Cross records were abstracted. Structural details on houses were collected from tax assessor records. Cases were more likely than controls to have been in multistorey houses than in single-storey houses (OR = 3.9; 95% CI: 1.2-13.2). The risk associated with houses built after 1972 (OR = 7.9) and those built from 1962 to 1972 (OR = 2.2) was greater than for those built before 1962 (OR = 1.0; chi 2 for trend = 12.1; P < 0.01). Being in the basement when the tornado hit was protective (OR = 0.1; 95% CI: 0.0-0.4). One-storey houses were safer than multistorey houses, and basements were safer than other rooms. The association of risk with the construction date of the house is a new finding and should be examined in further studies.

Microcoil embolization during abdominal vascular interventions through microcatheters with a tip of 2 French or less.

PubMed

Miyayama, Shiro; Yamashiro, Masashi; Hattori, Yuki; Orito, Nobuaki; Matsui, Ken; Tsuji, Kazunobu; Yoshida, Miki; Matsui, Osamu

2011-05-01

The aim of this study was to evaluate the technical aspects of embolization using microcoils through a microcatheter with a tip of 2F or smaller during abdominal vascular interventions. Coil embolization through a microcatheter with a tip of 2F or smaller was attempted in 73 procedures. Two types of microcoil-Liquid Coil (Boston Scientific, Watertown, MA, USA) and Tornado Coil (Cook, Bloomington, IN, USA)-were deployed through four types of thinner microcatheter [2F tip (n = 49) and 1.8F tip (n = 24)]. Coil jams in the microcatheter and coil migration were evaluated. In total, 286 microcoils were placed (mean ± SD, 3.9 ± 4.3 coils per procedure, range 1-32 coils). In 19 procedures (26.9%), Liquid Coils were used alone. In 44 (60.3%), Tornado Coils were used alone. In 10 (13.7%), Liquid Coils and Tornado Coils were combined. There were no coil jams in the microcatheter in this series. One Tornado Coil (0.3%) delivered into the gastroduodenal artery migrated to the right hepatic artery. Liquid Coils and Tornado Coils can be placed through a thinner microcatheter without difficulty. However, there is a risk of coil migration in large vessels or at the proximal site because the catheter tip is not stabilized.

Preparing for Emergencies: A Checklist for People with Neuromuscular Diseases

MedlinePlus

TORNADO • FLASH FLOOD • EARTHQUAKE • WINTER STORM • HURRICANE • FIRE • HAZARDOUS MATERIALS SPILL Preparing for Emergencies A Checklist for ... head for a basement when there is a tornado warning, but most basements aren’t wheelchair-accessible. ...

Tornadoes Strike Northern Wisconsin

NASA Technical Reports Server (NTRS)

2007-01-01

A series of tornadoes ripped through the Upper Midwest region of the United States in the evening of June 7, 2007. At least five different tornadoes touched down in Wisconsin, according to the Associated Press, one of which tore through the Bear Paw Resort in northern Wisconsin. Despite dropping as much as fifteen centimeters (six inches) of rain in some places and baseball-size hail in others, authorities were reporting no deaths attributable to the storm system, and only a smattering of injuries, but considerable property damage in some areas. When the MODIS instrument on NASA's Terra satellite observed the area on June 9, 2007, the track torn through the woods by one of the tornadoes stands out quite clearly. This photo-like image uses data collected by MODIS in the normal human vision range to give a familiar natural-looking appearance. The landscape is largely a checkerboard of farms, towns, roads, and cities. The pale land is predominantly farmland where crops have not fully grown in yet. Dark blue shows the winding path of rivers and lakes dotting the landscape. The large blue lake on the east (right) side of the image is Lake Michigan. Towns and cities, including the city of Green Bay, are gray. To the north side, farmland gives way to dark green as land use shifts from agriculture to the Menominee Indian Reservation and Nicolet National Forest. The diagonal slash through the dark green forested land shows the tornado track. Bare land was revealed where the tornado tore down trees or stripped vegetation off the branches. The high-resolution image provided above is at MODIS' full spatial resolution (level of detail) of 250 meters per pixel. The MODIS Rapid Response System provides this image at additional resolutions.

Detection Of Tornado Damage Tracks With EOS Data

NASA Technical Reports Server (NTRS)

Jedlovec, Gary J.; Nair, Udaysankar; Haines, Stephanie L.

2005-01-01

The damage surveys conducted by the NWS in the aftermath of a reported tornadic event are used to document the location of the tornado ground damage track (path length and width) and an estimation of the tornado intensity. This study explored the possibility of using near real-time medium and high-resolution satellite imagery from the NASA EOS satellites to provide additional information for the surveys. MODIS and ASTER data were used to study the damage tracks from three tornadic storms; the La Plata, Maryland storm of 28 April 2002 and the Carter-Butler Counties and Madison County Missouri storms of 24 April 2002. These storms varied in intensity (from F0-F4) and occurred over regions with different land use. It was found that, depending on the nature of land use, tornado damage tracks from intense storms (F2 or greater) may be evident in both ASTER and MODIS satellite imagery. In areas of dense vegetation the scar patterns show up very clearly, while in areas of grassland and regions with few trees, scar patterns are not at all obvious in the satellite imagery. The detection of previously unidentified segments of a damage track caused by the 24 April 2004 Madison County, Missouri tornado demonstrates the utility of satellite imagery for damage surveys. However, the capability to detect tornado tracks in satellite imagery appears to be as much dependent on the nature of the underlying surface and land use as on the severity of the tornadic storm. The imaging sensors on the NPOESS operational satellites to be launched in 2006 will continue the unique observing capabilities of the EOS instruments.

New NASA Satellite Zooms in on Tornado Swath

NASA Technical Reports Server (NTRS)

2002-01-01

A number of severe thunder storms swept through the mid-Atlantic states on April 28, bringing high winds, hailstones, and heavy rains to many areas. The intense storms spawned at least two tornadoes, one of which was classified as an F4 twister. The powerful tornado touched down in southern Maryland and ripped through the town of La Plata, destroying most of the historic downtown. The twister-the strongest ever recorded to hit the state and perhaps the strongest ever recorded in the eastern U.S.-flattened everything in its path along a 24-mile (39 km) swath running west to east through the state. The tornado's path can be seen clearly in this band-sharpened color image acquired on May 1 by the Advanced Land Imager (ALI), flying aboard NASA's EO-1 satellite. La Plata is situated toward the lefthand side of this scene and the twister's swath is the bright stripe passing through the town and running eastward 6 miles (10 km) toward the Patuxent River beyond the righthand side of the image. This stripe is the result of the vegetation flattened by the storm. The flattened vegetation reflects more light than untouched vegetation. EO-1 is the first Earth observing satellite launched as part of NASA's New Millennium Program. This program is designed to spearhead development and testing of a new generation of satellite remote sensing technologies for future Earth and space science missions. The ALI is designed to improve upon and extend the measurement heritage begun by the Landsat series of satellites well into the 21st Century. For more images of the tornado's path, including Landsat, visit Tornado Hits La Plata, Maryland in the Natural Hazards section of the Earth Observatory. Image courtesy Lawrence Ong, EO-1 Mission Science Office, NASA GSFC

Small rocket tornado probe

DOE Office of Scientific and Technical Information (OSTI.GOV)

Colgate, S.A.

1982-01-01

A (less than 1 lb.) paper rock tornado probe was developed and deployed in an attempt to measure the pressure, temperature, ionization, and electric field variations along a trajectory penetrating a tornado funnel. The requirements of weight and materials were set by federal regulations and a one-meter resolution at a penetration velocity of close to Mach 1 was desired. These requirements were achieved by telemetering a strain gage transducer for pressure, micro size thermister and electric field, and ionization sensors via a pulse time telemetry to a receiver on board an aircraft that digitizes a signal and presents it tomore » a Z80 microcomputer for recording on mini-floppy disk. Recording rate was 2 ms for 8 channels of information that also includes telemetry rf field strength, magnetic field for orientation on the rocket, zero reference voltage for the sensor op amps as well as the previously mentioned items also. The absolute pressure was recorded. Tactically, over 120 h were flown in a Cessna 210 in April and May 1981, and one tornado was encountered. Four rockets were fired at this tornado, missed, and there were many equipment problems. The equipment needs to be hardened and engineered to a significant degree, but it is believed that the feasibility of the probe, tactics, and launch platform for future tornado work has been proven. The logistics of thunderstorm chasing from a remote base in New Mexico is a major difficulty and reliability of the equipment another. Over 50 dummy rockets have been fired to prove trajectories, stability, and photographic capability. Over 25 electronically equipped rockets have been fired to prove sensors transmission, breakaway connections, etc. The pressure recovery factor was calibrated in the Air Force Academy blow-down tunnel. There is a need for more refined engineering and more logistic support.« less

Categorizing natural disaster damage assessment using satellite-based geospatial techniques

USGS Publications Warehouse

Myint, S.W.; Yuan, M.; Cerveny, R.S.; Giri, C.

2008-01-01

Remote sensing of a natural disaster's damage offers an exciting backup and/or alternative to traditional means of on-site damage assessment. Although necessary for complete assessment of damage areas, ground-based damage surveys conducted in the aftermath of natural hazard passage can sometimes be potentially complicated due to on-site difficulties (e.g., interaction with various authorities and emergency services) and hazards (e.g., downed power lines, gas lines, etc.), the need for rapid mobilization (particularly for remote locations), and the increasing cost of rapid physical transportation of manpower and equipment. Satellite image analysis, because of its global ubiquity, its ability for repeated independent analysis, and, as we demonstrate here, its ability to verify on-site damage assessment provides an interesting new perspective and investigative aide to researchers. Using one of the strongest tornado events in US history, the 3 May 1999 Oklahoma City Tornado, as a case example, we digitized the tornado damage path and co-registered the damage path using pre- and post-Landsat Thematic Mapper image data to perform a damage assessment. We employed several geospatial approaches, specifically the Getis index, Geary's C, and two lacunarity approaches to categorize damage characteristics according to the original Fujita tornado damage scale (F-scale). Our results indicate strong relationships between spatial indices computed within a local window and tornado F-scale damage categories identified through the ground survey. Consequently, linear regression models, even incorporating just a single band, appear effective in identifying F-scale damage categories using satellite imagery. This study demonstrates that satellite-based geospatial techniques can effectively add spatial perspectives to natural disaster damages, and in particular for this case study, tornado damages.

Categorizing natural disaster damage assessment using satellite-based geospatial techniques

NASA Astrophysics Data System (ADS)

Myint, S. W.; Yuan, M.; Cerveny, R. S.; Giri, C.

2008-07-01

Remote sensing of a natural disaster's damage offers an exciting backup and/or alternative to traditional means of on-site damage assessment. Although necessary for complete assessment of damage areas, ground-based damage surveys conducted in the aftermath of natural hazard passage can sometimes be potentially complicated due to on-site difficulties (e.g., interaction with various authorities and emergency services) and hazards (e.g., downed power lines, gas lines, etc.), the need for rapid mobilization (particularly for remote locations), and the increasing cost of rapid physical transportation of manpower and equipment. Satellite image analysis, because of its global ubiquity, its ability for repeated independent analysis, and, as we demonstrate here, its ability to verify on-site damage assessment provides an interesting new perspective and investigative aide to researchers. Using one of the strongest tornado events in US history, the 3 May 1999 Oklahoma City Tornado, as a case example, we digitized the tornado damage path and co-registered the damage path using pre- and post-Landsat Thematic Mapper image data to perform a damage assessment. We employed several geospatial approaches, specifically the Getis index, Geary's C, and two lacunarity approaches to categorize damage characteristics according to the original Fujita tornado damage scale (F-scale). Our results indicate strong relationships between spatial indices computed within a local window and tornado F-scale damage categories identified through the ground survey. Consequently, linear regression models, even incorporating just a single band, appear effective in identifying F-scale damage categories using satellite imagery. This study demonstrates that satellite-based geospatial techniques can effectively add spatial perspectives to natural disaster damages, and in particular for this case study, tornado damages.

Tornado from Texas.

ERIC Educational Resources Information Center

Vail, Kathleen

1996-01-01

Santa Fe School Superintendent Yvonne Gonzales, the "Texas Tornado," was hired to fix a 40% student-dropout rate and a white/Hispanic gap in achievement test scores. Gonzales is an avid integrationist; relies on humor, appeasement, and persuasion tactics; and has alienated some school employees by increasing central office…

Not Out of Control: Analysis of the Federal Disaster Spending Trend

DTIC Science & Technology

2016-03-01

included heavy rain, excessive rainfall, tropical storms, hurricanes, flooding, coastal flooding, wind, straight line winds, high winds, tornadoes ...straight line winds, tornadoes , high winds, coastal flooding, soil saturation, and mud flow.174 Despite the high number of severe storm declarations over

Electromagnetic tornado in the vacuum gap of a pulsar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kontorovich, V. M., E-mail: vkont1001@yahoo.co

The solution for an electromagnetic tornado that describes the motion in the discharge filament of breakdown in the vacuum gap of a pulsar has been obtained. This solution can serve as an explanation of the observed circular polarization of giant radiation pulses from pulsars.

The Power of Particles

Atmospheric Science Data Center

2017-11-27

... shows smoke in the atmosphere before and during the deadly tornado outbreak of April 27, 2011. Thin blue lines trace the flow of smoke ... shows smoke in the atmosphere before and during the deadly tornado outbreak of April 27, 2011. Thin blue lines trace the flow of smoke ...

Tornadoes and Lightning and Floods, Oh My! Weather-Related Web Sites for K-12 Science Lessons.

ERIC Educational Resources Information Center

Matkins, Juanita Jo; Murphy, Denise

1999-01-01

Reviews 30 weather-related Web sites, including readability level, under the subjects of air pressure, bad meteorology, clouds, droughts, floods, hurricanes, lightning, seasons, temperature, thunderstorms, tornadoes, water cycle, weather instruments, weather on other planets, and wind. (LRW)

Injuries from the wichita falls tornado: implications for prevention.

PubMed

Glass, R I; Craven, R B; Bregman, D J; Stoll, B J; Horowitz, N; Kerndt, P; Winkle, J

1980-02-15

We examined the circumstances of death and injury among victims of the tornado that struck Wichita Falls, Texas, on 10 April 1979. We also assessed the protective measures taken by a representative sample of community residents who suffered no major injury in order to estimate the relative risk of injury to people directly in the tornado's path. Twenty-six (60 percent) of the 43 traumatic deaths and 30 (51 percent) of the 59 serious injuries occurred in people who, despite ample warning, went to their cars to drive out of the storm's path. These people had a risk of serious or fatal injury of 23 per 1000. People who remained indoors and in stationary homes were at relatively low risk (3 per 1000) if they took simple precautions; people in mobile homes were at greatest risk (85 per 1000). Current safety recommendations and housing codes for single family homes and mobile homes need to be amended to decrease the impact of future tornadoes on human health.

ARE TORNADO-LIKE MAGNETIC STRUCTURES ABLE TO SUPPORT SOLAR PROMINENCE PLASMA?

DOE Office of Scientific and Technical Information (OSTI.GOV)

Luna, M.; Moreno-Insertis, F.; Priest, E.

Recent high-resolution and high-cadence observations have surprisingly suggested that prominence barbs exhibit apparent rotating motions suggestive of a tornado-like structure. Additional evidence has been provided by Doppler measurements. The observations reveal opposite velocities for both hot and cool plasma on the two sides of a prominence barb. This motion is persistent for several hours and has been interpreted in terms of rotational motion of prominence feet. Several authors suggest that such barb motions are rotating helical structures around a vertical axis similar to tornadoes on Earth. One of the difficulties of such a proposal is how to support cool prominencemore » plasma in almost-vertical structures against gravity. In this work we model analytically a tornado-like structure and try to determine possible mechanisms to support the prominence plasma. We have found that the Lorentz force can indeed support the barb plasma provided the magnetic structure is sufficiently twisted and/or significant poloidal flows are present.« less

Facebook and Twitter, communication and shelter, and the 2011 Tuscaloosa tornado.

PubMed

Stokes, Courtney; Senkbeil, Jason C

2017-01-01

This paper represents one of the first attempts to analyse the many ways in which Facebook and Twitter were used during a tornado disaster. Comparisons between five randomly selected campus samples and a city of Tuscaloosa, Alabama, sample revealed that campus samples used Facebook and Twitter significantly more both before and after the tornado, but Facebook usage was not significantly different after the event. Furthermore, differences in social media usage and other forms of communication before the tornado were found for age, education, and years lived in Tuscaloosa. Generally, age and education were inversely proportionate to social media usage. Influences on shelter-seeking actions varied between social media users and three random samples of non-social media users; however, it appears that social media respondents were likely to be using a smartphone simultaneously to access warning polygon information, to receive text message alerts, and to listen or respond to environmental cues. © 2017 The Author(s). Disasters © Overseas Development Institute, 2017.

Ionospsheric observation of enhanced convection-initiated gravity waves during tornadic storms

NASA Technical Reports Server (NTRS)

Hung, R. J.

1981-01-01

Atmospheric gravity waves associated with tornadoes, with locally severe storms occuring with tornadoes, and with hurricanes were studied through the coupling between the ionosphere and the troposphere. Reverse group ray tracing computations of gravity waves observed by an ionospheric Doppler sounder array were analyzed. The results of ray tracing computations and comparisons between the computed location of the wave sources and with conventional meteorological data indicate that the computed sources of the waves were near the touchdown of the tornadoes, near the eye of the hurricanes, and directly on the squall line of the severe thunderstorms. The signals excited occurred one hour in advance of the tornadoes and three hours in advance of the hurricanes. Satellite photographs show convective overshooting turrets occurring at the same locations and times the gravity waves were being excited. It is suggested that gravity wave observations, conventional meteorological data, and satellite photographs be combined to develop a remote sensing technique for detecting severe storms.

Building on a legacy for the era of population health.

PubMed

Brady, Marla G

2014-01-01

The 2011 Joplin tornado was a catastrophic EF5 multiple-vortex tornado that struck Joplin, Missouri, late in the afternoon of Sunday, May 22, 2011. It was part of a larger, late-May tornado outbreak and reached a maximum width of nearly 1 mile (1.6 km) during its path through the city. Mercy St John's Hospital (which had recently joined Mercy Ministries) suffered a direct hit and was rendered nonuseable. A total of 183 patients and nearly 200 coworkers/staff members were evacuated from the building within the next 90 minutes. Triage centers were set up outside as hospitals of other areas opened their doors for St John's patients and community members who had been injured. The tornado in Joplin destroyed Mercy St John's Hospital. Given this future, why did Mercy Ministries choose to rebuild an acute care facility rather than merely an outpatient system? The organization considered current community needs and the needs of the future. They also remembered their mission and the legacy of their heritage.

Pattern and spectrum of tornado injury and its geographical information system distribution in Yancheng, China: a cross-sectional study.

PubMed

Deng, Qiangyu; Lv, Yipeng; Xue, Chen; Kang, Peng; Dong, Junqiang; Zhang, Lulu

2018-06-22

Few studies of tornado injuries have considered differences related to damage levels and Enhanced-Fujita (EF) scale ratings. This study aimed to evaluate the pattern, spectrum and geographical distribution of injuries related to the Yancheng tornado and provide guidelines for effective emergency medical strategies. The study was conducted at three hospitals which treated patients with injuries related to the tornado in Yancheng, China. We obtained the records of 451 patients with tornado-related injuries. Of these, 401 valid trauma medical records were included; 50 other records were excluded for insufficient information. Informed consent was obtained from all patients by telephone. We analysed patients' injury sites and types and used the abbreviated injury scale (AIS) to standardise injury severity. Geographical information system and non-parametric tests were used to analyse the effects of geographical factors on casualties. Women, middle-aged/elderly individuals (age>45 years) and children/adolescents (<18 years) accounted for 51.62%, 77.30% and 12.47% of injured patients, respectively. This caused a dumbbell-shaped age distribution. Head (46.63%), body surface (39.90%) and lower-limb (29.43%) injuries were common, as were soft-tissue injuries (90.77%), fractures (38.90%) and organ damage (19.70%). Minor injuries (AIS=1) were common (60.85%), whereas critical/fatal injuries (AIS≥5) were very rare (2.50%). Although the densities of injury varied among damage levels and EF ratings for different areas, area-wise differences in injury severity (AIS scores) were not significant (p>0.05). We recommend the use of helmets to prevent head injuries caused by tornadoes and suggest prioritising the treatment of high-risk head and multiple-organ injuries. Additionally, medical rescuers should follow the 'same quality and different quantity' principle: the injured in all affected areas should receive equal attention, but numbers of medical personnel should be allocated based on the level of effects from the tornado. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Tornado project - The impact of catastrophic deforestation on the lake and peatland ecosystems of the Tuchola Pinewoods, Northern Poland

NASA Astrophysics Data System (ADS)

Słowiński, Michał; Lamentowicz, Mariusz; Łuców, Dominika; Kołaczek, Piotr; Tjallingii, Rik; Noryśkiewicz, Agnieszka M.; Zawiska, Izabela; Lane, Christine; Rzodkiewicz, Monika; Słowińska, Sandra; Kramkowski, Mateusz; Płóciennik, Mateusz; Tyszkowski, Sebastian; Łokas, Edyta; Kordowski, Jarosław; Brauer, Achim

2017-04-01

An increase in extreme weather phenomena has been observed over the last decades as a result of global climate warming. This project aims to investigate the effects of tornado events on the lake and peatland ecosystems of the Tuchola Pinewoods, Northern Poland. Deforestation by tornado events can cause severe perturbations of the soil hydrology and erosion that, in turn, affects adjacent lakes and peatlands. The Tuchola Pinewoods provide an exceptional possibility of studying the impact of such extreme events as it was struck by a tornado in 2012. This project focuses on lake - peatlands ecosystems that were directly affected by this tornado, with respect to the general transformation of the vegetation (mainly forests) over the last 300 years. Extensive clearing of the forest occurred in the nineteenth century due-to human agricultural activity, and we compare this with the impact of the 2012 tornado. Accurate reconstructions will rely on a broad range of palaeoecological techniques such as Cladocera, Chironomidae, diatoms, pollen, macroremains, testate amoebae, but also on geochemistry, i.e. μXRF scanning. We plan to analyses sediments of Kałębie and Martwe Lakes, as well as the adjacent Martwe peatland located along the path of the tornado. The chorology of the records collected will be based on 210Pb, 137Cs and radiocarbon dating as well as relative (crypto)tephra markers of the Eyjafjöll (2010) and Askja (1875) eruptions. This research addresses the emerging issue of the impact of extreme phenomena and more general climate changes on lake and peatland ecosystems, which potentially helps to adaptations to the environmental consequences of extreme events in the future. This project is funded by the Polish National Science Centre (No. 2015/17/B/ST10/03430) and is a contribution to the Virtual Institute of Integrated Climate and Landscape Evolution Analyses - ICLEA - of the Helmholtz Association and Science and Research Funds for 2015-2016, allocated to a co-financed international project (No. 3500/ICLEA/15/2016/0).

AXAOTHER XL -- A spreadsheet for determining doses for incidents caused by tornadoes or high-velocity straight winds

DOE Office of Scientific and Technical Information (OSTI.GOV)

Simpkins, A.A.

1996-09-01

AXAOTHER XL is an Excel Spreadsheet used to determine dose to the maximally exposed offsite individual during high-velocity straight winds or tornado conditions. Both individual and population doses may be considered. Potential exposure pathways are inhalation and plume shine. For high-velocity straight winds the spreadsheet has the capability to determine the downwind relative air concentration, however for the tornado conditions, the user must enter the relative air concentration. Theoretical models are discussed and hand calculations are performed to ensure proper application of methodologies. A section has also been included that contains user instructions for the spreadsheet.

Why do Tornados and Hail Storms Rest on Weekends?

NASA Technical Reports Server (NTRS)

Rosenfeld, Daniel; Bell, Thomas L.

2010-01-01

When anthropogenic aerosols over the eastern USA during summertime are at their weekly mid-week peak, tornado and hail storm activity there is also near its weekly maximum. The weekly cycle in storm activity is statistically significant and unlikely to be due to natural variability. The pattern of variability supports the hypothesis that air pollution aerosols invigorate deep convective clouds in a moist, unstable atmosphere, to the extent of inducing production of large hailstones and tornados. This is caused by the effect of aerosols on cloud-drop nucleation, making cloud drops smaller, delaying precipitation-forming processes and their evaporation, and hence affecting cloud dynamics.

Lightning rates relative to tornadic storm evolution on 22 May 1981

NASA Technical Reports Server (NTRS)

Macgorman, Donald R.; Burgess, Donald W.; Mazur, Vladislav; Rust, W. David; Taylor, William L.

1989-01-01

Lightning and Doppler radar data for two tornadic storms in Oklahoma on May 22, 1981 are used to analyze ground flash rates relative to the time of tornadoes. It is found that the ground flash rates had no obvious relationship with the tornado times, although the stroke rate in both storms was greatest after the tornadic stage ended. The variations in the cyclone shear and the intracloud flash rates within 10 km of the mesocyclone region are examined. The results suggest that most tornadic storms have an increase in total flash rates near the time of the tornado and that this increase is often dominated by intracloud flashes.

Rebuilding from the Rubble.

ERIC Educational Resources Information Center

Harper, John

1992-01-01

After tornado leveled Grand Prairie Elementary School (Joliet, Illinois), concerted effort by architects and the school community paid off when new school was opened two years later. Hallways in new building are staggered throughout school to avoid the creation of wind tunnels in event of another tornado. Guidelines for disaster preparations…

Do You Know Whats In Your Community A Strategic Risk Management Approach to Better Prepare for Chemical Emergencies

DTIC Science & Technology

2016-03-01

existing, or out-of-service process equipment • Track historical data concerning natural disasters such as tornados , hurricanes, floods, fires, or...hydrological, and meteorological (wildfire, flood, hurricane, tornado , earthquakes, tsunamis, volcanoes, etc.) • Identification of other

Standardized Technical Data Survey (STDS) for Aerial Refueling

DTIC Science & Technology

2016-09-06

the KC-135 and the German Tornado . The tanker/receiver combination was certified by a technical evaluation of the performance interface survey, face...another. That document was first used in assessing the compatibility of the KC-135 and the German Tornado . The survey questions, when accurately answered

Tornado Preparedness Planning.

ERIC Educational Resources Information Center

National Oceanic and Atmospheric Administration (DOC), Rockville, MD. National Weather Service.

This pamphlet contains a set of guidelines for community leaders interested in developing preparedness plans for tornadoes and severe thunderstorms. Included in the guide is a list of the types of officials and agencies which should be involved in planning meetings. A set of suggestions for developing a community communications network and…

Why do tornados and hailstorms rest on weekends?

NASA Astrophysics Data System (ADS)

Rosenfeld, Daniel; Bell, Thomas L.

2011-10-01

This study shows for the first time statistical evidence that when anthropogenic aerosols over the eastern United States during summertime are at their weekly mid-week peak, tornado and hailstorm activity there is also near its weekly maximum. The weekly cycle in summertime storm activity for 1995-2009 was found to be statistically significant and unlikely to be due to natural variability. It correlates well with previously observed weekly cycles of other measures of storm activity. The pattern of variability supports the hypothesis that air pollution aerosols invigorate deep convective clouds in a moist, unstable atmosphere, to the extent of inducing production of large hailstones and tornados. This is caused by the effect of aerosols on cloud drop nucleation, making cloud drops smaller and hydrometeors larger. According to simulations, the larger ice hydrometeors contribute to more hail. The reduced evaporation from the larger hydrometeors produces weaker cold pools. Simulations have shown that too cold and fast-expanding pools inhibit the formation of tornados. The statistical observations suggest that this might be the mechanism by which the weekly modulation in pollution aerosols is causing the weekly cycle in severe convective storms during summer over the eastern United States. Although we focus here on the role of aerosols, they are not a primary atmospheric driver of tornados and hailstorms but rather modulate them in certain conditions.

School interventions after the Joplin tornado.

PubMed

Kanter, Robert K; Abramson, David

2014-04-01

To qualitatively describe interventions by schools to meet children's needs after the May 2011 Joplin, Missouri tornado. Qualitative exploratory study conducted six months after the tornado. Key informant interviews with school staff (teachers, psychologists, guidance counselor, nurse, principal), public health official, and physicians. After the tornado, school staff immediately worked to contact every enrolled child to provide assistance and coordinate recovery services. Despite severe damage to half of the city's schools, the decision was made to reopen schools at the earliest possible time to provide a safe, reassuring environment and additional services. An expanded summer school session emphasized child safety and emotional wellbeing. The 2011-2012 school year began on time, less than three months after the disaster, using temporary facilities. Displaced children were bused to their usual schools regardless of their new temporary residence locations. In just-in-time training sessions, teachers developed strategies to support students and staff experiencing anxiety or depression. Certified counselors conducted school-based, small-group counseling for students. Selective referrals were made to community mental health providers for children with greatest needs. Evidence from Joplin adds to a small body of empirical experience demonstrating the important contribution of schools to postdisaster community recovery. Despite timely and proactive services, many families and children struggled after the tornado. Improvements in the effectiveness of postdisaster interventions at schools will follow from future scientific evidence on optimal approaches.

Numerical simulation of tornadoes' meteorological conditions over Greece: A case study of tornadic activity over NW Peloponnese on March 25, 2009

NASA Astrophysics Data System (ADS)

Matsangouras, Ioannis T.; Nastos, Panagiotis T.; Pytharoulis, Ioannis

2014-05-01

Recent research revealed that NW Peloponnese, Greece is an area that favours pre-frontal tornadic incidence. This study presents the results of the synoptic analysis of the meteorological conditions during a tornado event over NW Peloponnese on March 25, 2009. Further, the role of topography in tornado genesis is examined. The tornado was formed approximately at 10:30 UTC, south-west of Vardas village, crossed the Nea Manolada and faded away at Lappas village, causing several damage. The length of its track was approximately 9-10 km and this tornado was characterized as F2 (Fujita scale) or T4-T5 in TORRO intensity scale. Synoptic analysis was based on ECMWF datasets, as well as on daily composite mean and anomaly of the geopotential heights at the middle and lower troposphere from NCEP/NCAR reanalysis. In addition, numerous datasets derived from weather observations and remote sensing were used in order to interpret better the examined extreme event. Finally, a numerical simulation was performed using the non-hydrostatic Weather Research and Forecasting model (WRF), initialized with ECMWF gridded analyses, with telescoping nested grids that allow the representation of atmospheric circulations ranging from the synoptic scale down to the meso-scale. In the numerical simulations the topography of the inner grid was modified by: a) 0% (actual topography) and b) -100% (without topography).

The February 21, 1993 tornadoes of East Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fricke, K.E.; Kornegay, F.C.

1993-08-11

A series of tornadoes struck the east Tennessee area on Sunday afternoon, February 21, 1993 around Knoxville, Lenoir City, and Oak Ridge causing millions of dollars worth of damage to both homes and businesses in the area, killing one, injuring a number of persons, and leaving a large area without power for many hours or even days due to damage to the local TVA transmission line network. One tornado touched down in the Department of Energy Oak Ridge Reservation near the Oak Ridge Y-12 Plant, continued through the Union Valley business district located just east of the plant, through themore » adjacent University of Tennessee Arboretum and then continued into the communities of Claxton and Powell. The path length of the tornado was approximately 13 miles. Damage to the Y-12 Plant was minimal, but the Union Valley business district was seriously damaged, including the Fusion Energy Design Center (FEDC) which houses a number of DOE related projects. The preliminary cost estimate of the damage to DOE facilities (both at Y-12 and at the FEDC) was around $520,000. This paper describes the local meteorological data, the tornado that struck near the Y-12 plant, the resulting damage both to the DOE facilities and to the surrounding communities, the plant emergency response and recovery activities, and the current hazard analyses being undertaken at the plant.« less

Journalists Feel Need to Report on Tornadoes.

ERIC Educational Resources Information Center

Corder, Paige; Houston, Hillary; Phan, Christine; Ruyle, Jessica

1999-01-01

Describes the production of a special edition by Brink Junior High, Moore West Junior High, and Westmoore High School (Moore, Oklahoma) after a tornado destroyed entire neighborhoods only days before. Notes the positive reaction of students and the community, as well as the sense of unity that developed in the community. (RS)

Utilizing Tornado Data for Classroom Exercises.

ERIC Educational Resources Information Center

Kohler, Fred

Exercises were developed using tornado statistics to provide students with a better understanding of the spatial and temporal characteristics of these phenomena in the United States. Four categories of exercises were considered beginning with the simplest and progressing to the more complex. The first set of exercises required students to…

Emotional Reactions of Rescue Workers Following a Tornado.

ERIC Educational Resources Information Center

McCammon, Susan L.; And Others

Rescue and medical workers may be at risk for negative emotional experience following intervention efforts in disaster situations. To examine this possibility, 120 rescue and hospital personnel responded to a survey of their emotional reactions and coping behaviors 3 months after a devastating tornado. Twenty-eight subjects had been involved in…

Analytic studies on satellite detection of severe, two-cell tornadoes

NASA Technical Reports Server (NTRS)

Carrier, G. F.; Dergarabedian, P.; Fendell, F. E.

1979-01-01

It is argued that a two-cell structure is likely to be the unique property, and potentially satellite-accessible observable, of the exceptionally severe tornado. Analysis elucidating the dynamic, thermodynamic, and geometric properties of this two-cell structure is described. The analysis ultimately will furnish instrumentation requirements.

A Twist of Fate: Tornado Strikes Four ACA Camps.

ERIC Educational Resources Information Center

Brokaw, Christine O'Connor

1989-01-01

Describes the reactions of four Connecticut camps to a July 1989 tornado. Discusses damages incurred, the importance of emergency plans, reactions of campers and staff, the use of a crisis management team, budgeting for emergencies, communications with campers' families, rebuilding, and reopening. Suggests disasters, handled properly, can be…

Bottomland hardwood forest recovery following tornado disturbance and salvage logging

Treesearch

John L. Nelson; John W. Groninger; Loretta L. Battaglia; Charles M. Ruffner

2008-01-01

Catastrophic wind events, including tornado, hurricane. and linear winds. are significant disturbances in temperate forested wetlands. Information is lacking on how post-disturbance salvage logging may impact short and long-term objectives in conservation areas where natural stands are typically managed passively. Woody regeneration and herbaceous cover were assessed...

Touchable Tornadoes

ERIC Educational Resources Information Center

Gilhousen, David

2004-01-01

In this article, the author discusses a tornado-producing machine that he used in teacher-led, student assisted demonstrations in order to reinforce concepts learned during a unit on weather. The machine, or simulator, was powered by a hair dryer, fan, and cool-mist humidifier. The machine consists of a demonstration table containing a plenum box,…

Tornado: School Damage Tops $3 Million.

ERIC Educational Resources Information Center

Story, Nancy

1999-01-01

Describes efforts by the publications staff of North Hall High School (Gainesville, Georgia) to cover a tornado and its aftermath. Notes that the first issue published after the storm focused in intrusion by the media. Suggests that an anniversary issues was more effective in achieving the emotional catharsis the school needed. (RS)

Forest structure following tornado damage and salvage logging in northern Maine, USA

Treesearch

Shawn Fraver; Kevin J. Dodds; Laura S. Kenefic; Rick Morrill; Robert S. Seymour; Eben Sypitkowski

2017-01-01

Understanding forest structural changes resulting from postdisturbance management practices such as salvage logging is critical for predicting forest recovery and developing appropriate management strategies. In 2013, a tornado and subsequent salvage operations in northern Maine, USA, created three conditions (i.e., treatments) with contrasting forest structure:...

Tornado! An Event-Based Science Module. Teacher's Guide. Meteorology Module.

ERIC Educational Resources Information Center

Wright, Russell G.

This book is designed for middle school earth science teachers to help their students learn about problems with tornadoes and scientific literacy through event-based science. Unlike traditional curricula, the event-based earth science module is a student-centered, interdisciplinary, inquiry-oriented program that emphasizes cooperative learning,…

76 FR 70971 - Proposed Information Collection; Comment Request; Societal Response to Tornado Warnings

Federal Register 2010, 2011, 2012, 2013, 2014

2011-11-16

... developing social science, wishes to examine the societal impacts of tornado warnings, specifically the methods of receipt, response, and the impact of false alarms on the rate in which protective actions are... ). FOR FURTHER INFORMATION CONTACT: Requests for additional information or copies of the information...

Tornadoes & Hurricanes. The Natural Disaster Series. Grades 4-8.

ERIC Educational Resources Information Center

Deery, Ruth

The topics of tornadoes and hurricanes are important to children but are often missing from elementary textbooks. This document is a part of "The Natural Disaster Series" and is an attempt to supplement elementary science and social studies programs with lessons and student activities. Reasoning skills are emphasized throughout the…

Assessment of a severe-weather warning system and disaster preparedness, Calhoun County, Alabama, 1994.

PubMed Central

Liu, S; Quenemoen, L E; Malilay, J; Noji, E; Sinks, T; Mendlein, J

1996-01-01

Tornado preparedness warning system effectiveness, and shelter-seeking behavior were examined in two Alabama areas after tornado warnings. In the area without sirens, only 28.9% of 194 respondents heard a tornado warning of these, 73.2% first received the warning from radios or television. In the area with sirens, 88.1% of 193 respondents heard a warning, and 61.8% first received the warning from a siren. Knowledge of warnings, access to shelter, and education were key predictors for seeking shelter. Our findings indicate that installing sirens, providing access to shelter, and teaching appropriate responses to warnings are important elements of an effective disaster prevention system. PMID:8561251

Pseudoaneurysm of the thoracic aorta sustained during exposure to a tornado diagnosed with ECG-synchronized CT aortography.

PubMed

Chakraborty, Amit; von Herrmann, Paul F; Embertson, Ryan E; Landwehr, Kevin P; Winkler, Michael A

2016-01-01

A case of a tornado victim with a delayed presentation of injury to the aortic isthmus is discussed. Tornado forces resemble the forces of high energy explosions, and the injuries that can occur as a result of these forces can be bizarre. The patient presented with the unique computed tomography (CT) findings of isolated pseudoaneurysm of the thoracic aorta in the absence of other traumatic injury to the thorax. Equivocal results of the initial CT aortogram (CTA) were confirmed with ECG-synchronized CTA (ECG-CTA), demonstrating the superiority of ECG-CTA as compared to standard CTA. Copyright © 2016 Elsevier Inc. All rights reserved.

Microprocessors as a tool in determining correlation between sferics and tornado genesis. [Sferics = atmospheric electromagnetic radiation in the kilohertz to UHF range

DOE Office of Scientific and Technical Information (OSTI.GOV)

Witte, D.R.

1978-11-01

It is believed that sferics, a word that stands for atmospheric electromagnetic radiation, can be correlated to the genesis of tornadoes and severe weather. Sferics are generated by lightning and other atmospheric disturbances that are not yet entirely understood. The recording and analysis of the patterns in which sferic events occur, it is hoped, will lead to accurate real-time prediction of tornadoes and other severe weather. Collection of this data becomes cumbersome when correlation between at least two stations is necessary for triangulation; however, the advent of microprocessors has made the task of data collection and massaging inexpensive and manageable.

Cloud-to-ground lightning in a tornadic storm on 8 May 1986

NASA Technical Reports Server (NTRS)

Macgorman, Donald R.; Nielsen, Kurt E.

1991-01-01

The National Severe Storms Laboratory (NSSL) gathered Doppler radar and lightning ground strike data on a supercell storm that produced three tornadoes, including an F3 tornado in Edmond, Oklahoma, approximately 40 km north of NSSL. The Edmond storm formed 30 km ahead of a storm complex and developed its first and most damaging tornado just as the storm complex started to overtake it from the west. Lightning strike locations tended to concentrate just north of the mesocyclone, close to and inside a 50 dBZ reflectivity core. Positive ground flashes began just prior to the storm becoming tornadic, and positive flash rates peaked during the tornadic stage of the storm.

NOAA Photo Library -

Science.gov Websites

logo and clouds NSSL is one of the National Oceanic and Atmospheric Administration's internationally of tornado Tornadoes picture of vintage doppler radar Instruments picture of clouds Sky Scenes -known Environmental Research Laboratories, leading the way in investigations of all aspects of severe

Towards a theory of stochastic vorticity-augmentation. [tornado model

NASA Technical Reports Server (NTRS)

Liu, V. C.

1977-01-01

A new hypothesis to account for the formation of tornadoes is presented. An elementary one-dimensional theory is formulated for vorticity transfer between an ambient sheared wind and a transverse penetrating jet. The theory points out the relevant quantities to be determined in describing the present stochastic mode of vorticity augmentation.

Prevalence and Predictors of PTSD and Depression among Adolescent Victims of the Spring 2011 Tornado Outbreak

ERIC Educational Resources Information Center

Adams, Zachary W.; Sumner, Jennifer A.; Danielson, Carla Kmett; McCauley, Jenna L.; Resnick, Heidi S.; Grös, Kirstin; Paul, Lisa A.; Welsh, Kyleen E.; Ruggiero, Kenneth J.

2014-01-01

Background: Relatively few studies have examined prevalence and predictors of posttraumatic stress disorder (PTSD) or major depressive episode (MDE) in disaster-affected adolescents. Fewer still have administered diagnostic measures or studied samples exposed to tornadoes, a common type of disaster. Further, methodologic problems limit the…

Scientist Examines Tornado Vortex

NASA Technical Reports Server (NTRS)

1999-01-01

In this Quick Time movie, a scientist examines what appears to be a tornado vortex (blue) coming out of a thunderstorm. The scientist uses 3D glasses to be able to see in 3 dimensions the different flows going out into the vortex. Earth science and weather studies are an important ongoing function of NASA and its affiliates.

Tornado chasing: an introduction to risk tourism opportunities

Treesearch

Heather Cantillon; Robert S. Bristow

2001-01-01

Tours devoted to tornado storm chasing have become popular in recent years, especially with the emergence of many profit and non-profit storm chasing organizations. While most literature in risk recreation has been directed toward rock climbing or other high-risk outdoor recreation activities, tours devoted to storm chasing are quite unlike these traditional activities...

Methods and reagents. Degraded DNA and gel tornados.

PubMed

Hengen, P N

1997-04-01

Methods and reagents is a unique monthly column that highlights current discussions in the newsgroup bionet.molbio.methds-reagnts, available on the Internet. This month's column discusses a case of inexplicable DNA degradation and tornados seen in agarose gels. For details on how to partake in the newsgroup, see the accompanying box.

Effects of atomic explosions on the frequency of tornadoes in the United States

DOE Office of Scientific and Technical Information (OSTI.GOV)

Harris, D.L.

1951-01-01

The increase in tornadoes reported in the United States during the past few years is ascribed to better reporting procedures rather than the presence of atomic debris. Maps showing the distribution of fall-out in the United States during the first and second halves of May, 1953, are given.

Comparison of remote sensing image processing techniques to identify tornado damage areas from Landsat TM data

USGS Publications Warehouse

Myint, S.W.; Yuan, M.; Cerveny, R.S.; Giri, C.P.

2008-01-01

Remote sensing techniques have been shown effective for large-scale damage surveys after a hazardous event in both near real-time or post-event analyses. The paper aims to compare accuracy of common imaging processing techniques to detect tornado damage tracks from Landsat TM data. We employed the direct change detection approach using two sets of images acquired before and after the tornado event to produce a principal component composite images and a set of image difference bands. Techniques in the comparison include supervised classification, unsupervised classification, and objectoriented classification approach with a nearest neighbor classifier. Accuracy assessment is based on Kappa coefficient calculated from error matrices which cross tabulate correctly identified cells on the TM image and commission and omission errors in the result. Overall, the Object-oriented Approach exhibits the highest degree of accuracy in tornado damage detection. PCA and Image Differencing methods show comparable outcomes. While selected PCs can improve detection accuracy 5 to 10%, the Object-oriented Approach performs significantly better with 15-20% higher accuracy than the other two techniques. ?? 2008 by MDPI.

Experimental Study on Effects of Ground Roughness on Flow Characteristics of Tornado-Like Vortices

NASA Astrophysics Data System (ADS)

Wang, Jin; Cao, Shuyang; Pang, Weichiang; Cao, Jinxin

2017-02-01

The three-dimensional wind velocity and dynamic pressure for stationary tornado-like vortices that developed over ground of different roughness categories were investigated to clarify the effects of ground roughness. Measurements were performed for various roughness categories and two swirl ratios. Variations of the vertical and horizontal distributions of velocity and pressure with roughness are presented, with the results showing that the tangential, radial, and axial velocity components increase inside the vortex core near the ground under rough surface conditions. Meanwhile, clearly decreased tangential components are found outside the core radius at low elevations. The high axial velocity inside the vortex core over rough ground surface indicates that roughness produces an effect similar to a reduced swirl ratio. In addition, the pressure drop accompanying a tornado is more significant at elevations closer to the ground under rough compared with smooth surface conditions. We show that the variations of the flow characteristics with roughness are dependent on the vortex-generating mechanism, indicating the need for appropriate modelling of tornado-like vortices.

Comparison of Remote Sensing Image Processing Techniques to Identify Tornado Damage Areas from Landsat TM Data

PubMed Central

Myint, Soe W.; Yuan, May; Cerveny, Randall S.; Giri, Chandra P.

2008-01-01

Remote sensing techniques have been shown effective for large-scale damage surveys after a hazardous event in both near real-time or post-event analyses. The paper aims to compare accuracy of common imaging processing techniques to detect tornado damage tracks from Landsat TM data. We employed the direct change detection approach using two sets of images acquired before and after the tornado event to produce a principal component composite images and a set of image difference bands. Techniques in the comparison include supervised classification, unsupervised classification, and object-oriented classification approach with a nearest neighbor classifier. Accuracy assessment is based on Kappa coefficient calculated from error matrices which cross tabulate correctly identified cells on the TM image and commission and omission errors in the result. Overall, the Object-oriented Approach exhibits the highest degree of accuracy in tornado damage detection. PCA and Image Differencing methods show comparable outcomes. While selected PCs can improve detection accuracy 5 to 10%, the Object-oriented Approach performs significantly better with 15-20% higher accuracy than the other two techniques. PMID:27879757

On the Magnetism and Dynamics of Prominence Legs Hosting Tornadoes

NASA Astrophysics Data System (ADS)

Martínez González, M. J.; Asensio Ramos, A.; Arregui, I.; Collados, M.; Beck, C.; de la Cruz Rodríguez, J.

2016-07-01

Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show that the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves).

ON THE MAGNETISM AND DYNAMICS OF PROMINENCE LEGS HOSTING TORNADOES

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martínez González, M. J.; Ramos, A. Asensio; Arregui, I.

2016-07-10

Solar tornadoes are dark vertical filamentary structures observed in the extreme ultraviolet associated with prominence legs and filament barbs. Their true nature and relationship to prominences requires an understanding of their magnetic structure and dynamic properties. Recently, a controversy has arisen: is the magnetic field organized forming vertical, helical structures or is it dominantly horizontal? And concerning their dynamics, are tornadoes really rotating or is it just a visual illusion? Here we analyze four consecutive spectro-polarimetric scans of a prominence hosting tornadoes on its legs, which helps us shed some light on their magnetic and dynamical properties. We show thatmore » the magnetic field is very smooth in all the prominence, which is probably an intrinsic property of the coronal field. The prominence legs have vertical helical fields that show slow temporal variation that is probably related to the motion of the fibrils. Concerning the dynamics, we argue that (1) if rotation exists, it is intermittent, lasting no more than one hour, and (2) the observed velocity pattern is also consistent with an oscillatory velocity pattern (waves).« less

A preliminary look at the impact of warming Mediterranean Sea temperatures on some aspects of extreme thunderstorm events in Italy

NASA Astrophysics Data System (ADS)

Gallus, William; Parodi, Antonio; Miglietta, Marcello; Maugeri, Maurizio

2017-04-01

As the global climate has warmed in recent decades, interest has grown in the impacts on extreme events associated with thunderstorms such as tornadoes and intense rainfall that can cause flash flooding. Because warmer temperatures allow the atmosphere to contain larger values of water vapor, it is generally accepted that short-term rainfall may become more intense in a future warmer climate. Regarding tornadoes, it is more difficult to say what might happen since although increased temperatures and humidity in the lowest part of the troposphere should increase thermodynamic instability, allowing for stronger thunderstorm updrafts, vertical wind shear necessary for storm-scale rotation may decrease as the pole to equator temperature gradient weakens. The Mediterranean Sea is an important source for moisture that fuels thunderstorms in Italy, and it has been warming faster than most water bodies in recent decades. The present study uses three methods to gain preliminary insight into the role that the warming Mediterranean may have on tornadoes and thunderstorms with intense rainfall in Italy. First, a historical archive of Italian tornadoes has been updated for the 1990s, and it will be used along with other data from the European Severe Weather Database to discuss possible trends in tornado occurrence. Second, convection-allowing Weather Research and Forecasting (WRF) model simulations have been performed for three extreme events to examine sensitivity to both the sea surface temperatures and other model parameters. These events include a flash flood-producing storm event near Milan, a non-tornadic severe hail event in far northeastern Italy, and the Mira EF-4 tornado of July 2015. Sensitivities in rainfall amount, radar reflectivity and storm structure, and storm rotation will be discussed. Finally, changes in the frequency of intense mesoscale convective system events in and near the Ligurian Sea, inferred from the presence of strong convergence lines in EXPRESS-Hydro regional climate model output, will be examined.

An impact of deforestation by extreme weather events on Sphagnum peatland ecosystem

NASA Astrophysics Data System (ADS)

Slowinski, M. M.; Łuców, D.; Kołaczek, P.; Tjallingii, R.; Lane, C. S.; Slowinska, S.; Tyszkowski, S.; Łokas, E.; Theuerkauf, M.; Brauer, A.; Lamentowicz, M.

2017-12-01

An increase in extreme weather phenomena has been observed over the last decades as a result of global climate warming. Terrestrial ecosystems are influenced by different types of disturbances such as e.g. deforestation, land-use, fragmentation, fire, floods or storms. Disturbance triggers may be natural or anthropogenic, but usually we observe negative feedback loops and interconnected causal factors. Here we investigate the effects of a tornado event on the peatland ecosystem of the Tuchola Pinewoods, Northern Poland. Deforestation by tornado events can cause severe perturbations of the hydrology and erosion that, in turn, affects adjacent lakes and peatlands. Martwe peatland provide an exceptional opportunity to study the impact of such extreme events, as it was struck by a tornado in 2012. Our research is focused on lake-peatland ecosystems that were directly affected by this tornado, and we consider the general transformation of the vegetation (mainly forests) over the last 150 years. Extensive clearing of the forest occurred in the nineteenth century due to human activity, and we compare this with the impact of the 2012 tornado. Accurate reconstructions will rely on a broad range of palaeoecological techniques such as pollen, macro-remains and testate amoebae, but also on geochemistry, i.e. μXRF scanning. The chronology of the records is based on 210Pb and radiocarbon dating and will incorporate correlations using (crypto)tephra markers of the Eyjafjöll (2010) and Askja (1875) eruptions. We expect to observe that disturbance (tornado-induced deforestation) affects the short-term changes in peatland productivity and biodiversity, through a cascading "top-down" effect. This research addresses the emerging issue of the impact of extreme phenomena and more general climate changes on peatland ecosystems, which will potentially help to inform adaptations to the environmental consequences of extreme events in the future. This project is funded by the Polish National Science Centre (No. 2015/17/B/ST10/03430).

On the measurement of wind speeds in tornadoes with a portable CW/FM-CW Doppler radar

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bluestein, H.B.; Unruh, W.P.

1991-01-01

Both the formation mechanism and structure of tornadoes are not yet well understood. The Doppler radar is probably the best remote-sensing instrument at present for determining the wind field in tornadoes. Although much has been learned about the non-supercell tornado from relatively close range using Doppler radars at fixed sites, close-range measurements in supercell tornadoes are relatively few. Doppler radar can increase significantly the number of high-resolution, sub-cloud base measurements of both the tornado vortex and its parent vortex in supercells, with simultaneous visual documentation. The design details and operation of the CW/FM-CW Doppler radar developed at the Los Alamosmore » National Laboratory and used by storm-intercept teams at the Univ. of Oklahoma are described elsewhere. The radar transmits 1 W at 3 cm, and can be switched back and forth between CW and FM-CW modes. In the FM-CW mode the sweep repetition frequency is 15.575 kHz and the sweep width 1.9 MHz; the corresponding maximum unambiguous range and velocity, and range resolution are 5 km, {plus minus} 115 m s{sup {minus}1}, and 78 m respectively. The bistatic antennas, which have half-power beamwidths of 5{degree}, are easily pointed wit the aid of a boresighted VCR. FM-CW Data are recorded on the VCR, while voice documentation is recorded on the audio tape; video is recorded on another VCR. The radar and antennas are easily mounted on a tripod, and can be set up by three people in a minute or two. The purpose of this paper is to describe the signal processing techniques used to determine the Doppler spectrum in the FM-CW mode and a method of its interpretation in real time, and to present data gathered in a tornadic storm in 1990. 15 refs., 7 figs.« less

A pseudo-dual-Doppler analysis of cyclic tornadogenesis

NASA Astrophysics Data System (ADS)

Dowell, David Collin

2000-06-01

Several tornadic storms formed in the Texas Panhandle on 8 June 1995, the date of the last mission of VORTEX (Verification of the Origins of Rotation in Tornadoes EXperiment). The southernmost storm in this severe weather outbreak produced a family of at least five tornadoes near the town of McLean. Airborne Doppler radar scans of this storm by the ELDORA (ELectra DOppler RAdar) offer the most detailed look to date at a storm producing a family of tornadoes. The goals of this study were twofold. The first was to determine a pseudo-dual-Doppler wind synthesis method in Cartesian coordinates appropriate for the analysis of the ELDORA data. Unique aspects of this part of the study include a comparison of wind synthesis methods based on variational formulations and the use of a non-uniform moving reference frame for the syntheses. A dual-Doppler formulation in which the radial velocity and continuity equations are all satisfied as weak constraints (Gamache 1997, Shapiro and Mewes 1999) yields a more accurate wind field than traditional (and variational) methods in which the radial velocity equations are satisfied exactly. The second goal of this study was to diagnose both the cyclic process and the formation of individual tornadoes. The McLean storm produced three large tornadoes at 18 min intervals. The last of these then lasted much longer (over one hour) and was stronger than the previous tornadoes. New pre-tornadic vortices formed on the east side of the updraft by tilting of strong environmental low-level horizontal vorticity into the vertical and then stretching of the vertical vorticity within the updraft. The vortices did not mature at low levels until they migrated to the west side of the updraft. Indirect evidence indicates that both baroclinic generation of horizontal vorticity and the rear downdraft may have played roles in tornado formation at this stage. The tornadic potential of a storm appears-to be related to the relative strength of low-level storm outflow and inflow beneath the west side of updraft. Cyclic tornadogenesis modes may be possible both when the inflow slightly dominates and when the outflow slightly dominates. The description of an inflow-dominated cyclic mode like that observed in the McLean storm is original. Internal cell interactions within the McLean storm appear to have helped the transition from the cyclic phase to a more steady phase.

An Observational Study on Quantifying the Distance of Supercell-Boundary Interaction in the Great Plains

NASA Astrophysics Data System (ADS)

Magee, Kathleen Marie

Several case studies and numerical simulations have confirmed that baroclinic boundaries provide enhanced horizontal and vertical vorticity, wind shear, helicity, and moisture that induce stronger updrafts, higher reflectivity, and stronger low-level rotation in supercells. However, the distance at which a boundary will provide such enhancement is less well-defined. Previous studies have identified distances ranging from 5 km to 200 km, and only focused on tornadogenesis rather than all forms of severe weather. To better aid short-term forecasts, the actual distances at which supercells produce severe weather in proximity to a boundary needs to be assessed. In this study, the distance between a large number of supercells and nearby surface boundaries (including warm fronts, stationary fronts, and outflow boundaries) is measured throughout the lifetime of each storm; the distance at which associated reports of large hail, strong winds, and tornadoes is also collected. Data is gathered from SPC storm reports, WPC surface analyses, ASOS archives, and NCDC radar archives. The Integrated Data Viewer (IDV) from Unidata is used to analyze the distance of the supercell from the boundary every twenty minutes. These distances are then used to interpolate the distance at which severe and significantly severe reports occurred; reports are grouped by severe type (tornado, hail, or wind), then by boundary type (warm front, stationary front, or outflow). Using these distributions, the range from the boundary at which each type of severe weather is produced is identified per boundary type to assist forecasters. Overall, the range at which tornadoes are more likely to be produced is generally closer to the boundary than hail and wind reports for all three boundary types, likely owing to the enhanced helicity present near a boundary. Statistical analyses are used to assess the sensitivity of report distributions to report type, boundary type, distance from the boundary, and boundary strength. The distance of different report types near the same boundary surprisingly did not test as statistically different, except for warm fronts; however, when comparing the distances of the same report type associated with different boundaries, statistically significant differences were found for different boundaries in which different report types are maximally produced. Temperature gradients are not as statistically different between boundaries, but the temperature gradient within the same boundary is statistically significant for the occurrence of tornadoes vs. hail. Additional analyses were conducted to complement the distributions of severe report distances. Previous research has demonstrated that the angle at which supercells interact with boundaries impacts tornado production; in the present dataset, supercells interacting at an angle less than 45° are not only more likely to produce tornadoes, but also more likely to produce significantly severe tornadoes. Additionally, other studies have suggested that the temperature gradient of a boundary is of minimal importance with regards to tornado production. Interestingly, the tornadoes in this study were associated with stronger temperature gradients than for hail or wind production, thus v implying that a stronger amount of baroclinically-generated horizontal vorticity is required for tornadogenesis, likely due to the enhanced low-level rotation.

The Effects of a Natural Disaster on Academic Abilities and Social Behavior of School Children.

ERIC Educational Resources Information Center

Martin, Sander; Little, Brenda

1986-01-01

Measures such as achievement test scores, school absences, grades, and citizenship were used to examine effects of a 1979 tornado disaster on fourth and fifth graders over a four-year period. Overall results indicated no significant differences between victims, observers of the tornado, and new residents. Related research and implications are…

Eliminate the Army and Air Force Reserves: Building a Robust National Guard to Meet 21st Century Operational Challenges

DTIC Science & Technology

2016-04-04

structure. Weather Reconnaissance capability would aid the Guard in gathering meteorological intelligence in preparation for hurricane or tornado domestic...Reserve units by relating it to an emergency response in Missouri. On May 22, 2011, a tornado struck Joplin, killing 158 people and injuring 1,000

Seeing Tornado: How Video Traces Mediate Visitor Understandings of (Natural?) Phenomena in a Science Museum.

ERIC Educational Resources Information Center

Stevens, Reed; Hall, Rogers

1997-01-01

Reports on an exploratory study of how people see and explain a prominent exhibit (Tornado) at an interactive science museum (the Exploratorium). Data was assembled using a novel, technically mediated activity system (Video Traces). Argues that Video Traces is an effective tool and discusses an expanded Video Traces system. (Author/DKM)

Medical response to a natural disaster: the Barrie tornado.

PubMed Central

Morris, B A; Armstrong, T M

1986-01-01

On May 31, 1985, a tornado devastated an area of Barrie, Ont. Following a prepared disaster plan, the staff of the local hospital managed 155 casualties, including 16 cases of multiple trauma, over 5 hours. The authors summarize the hospital's experience and give recommendations to help the staff of other hospitals improve their disaster plans. PMID:3948094

Ruin Gives Way to Renewal in Joplin

ERIC Educational Resources Information Center

Samuels, Christina A.

2012-01-01

Just days before a massive tornado devastated their community last May, a group of Joplin, Mo., educators and other community members had a meeting about "21st-century learning." Then May 22 arrived, bringing the catastrophic storm that ripped through the community of 50,000 in the southwest corner of the state. The tornado killed 161…

Real-Time Forecasting of Echo-Centroid Motion.

DTIC Science & Technology

1979-01-01

is apparent that after five observations are obtained, the forecast error drops considerably. The normal lifetime of an echo (25 to 30 min) is...10kmI I ! Fig. 11. Track of 5 April 1978 mesocyclone (M) and two TVS’s (1) and (2). Times are CST. Pumpkin Center tornado is hatched and Marlow tornado is

Techniques used to identify tornado producing thunderstorms using geosynchronous satellite data

NASA Technical Reports Server (NTRS)

Schrab, Kevin J.; Anderson, Charles E.; Monahan, John F.

1992-01-01

Satellite imagery in the outbreak region in the time prior to and during tornado occurrence was examined in detail to obtain descriptive characteristics of the anvil plume. These characteristics include outflow strength (UMAX), departure of anvil centerline from the storm relative ambient wind (MDA), storm relative ambient wind (SRAW), and maximum surface vorticity (SFCVOR). It is shown that by using satellite derived parameters which characterize the flow field in the anvil region, the occurrence and intensity of tornadoes, which the parent thunderstorm produces, can be identified. Analysis of the censored regression models revealed that the five explanatory variables (UMAX, MDA, SRAW, UMAX-2, and SFCVOR) were all significant predictors in the identification of tornadic intensity of a particular thunderstorm.

Technical concept of the UK Tornado stand-off reconnaissance system

NASA Astrophysics Data System (ADS)

Dyer, Gavin R.

1996-11-01

The operational limitations exposed during the Gulf War have led to the formulation of a requirement for anew generation of tactical reconnaissance pod for the Royal Air Force Tornado aircraft. The pod will contain a high resolution Electro-Optical sensor capable of day and night-time operations, digital recording of the imagery for airborne replay and ground exploitation, and a data-link for real time/near real time imagery transmission. The program requirement includes a deployable ground exploitation system to provide a comprehensive independent capability. The interoperability of the air and ground segments with other systems is addressed through NATO standardization agreements. This system will provide the Tornado with a highly flexible stand-off imaging system for day/night operations from a range of altitudes.

Assessment of biomass burning smoke influence on environmental conditions for multi-year tornado outbreaks by combining aerosol-aware microphysics and fire emission constraints.

PubMed

Saide, Pablo E; Thompson, Gregory; Eidhammer, Trude; da Silva, Arlindo M; Pierce, R Bradley; Carmichael, Gregory R

2016-09-16

We use the WRF system to study the impacts of biomass burning smoke from Central America on several tornado outbreaks occurring in the US during spring. The model is configured with an aerosol-aware microphysics parameterization capable of resolving aerosol-cloud-radiation interactions in a cost-efficient way for numerical weather prediction (NWP) applications. Primary aerosol emissions are included and smoke emissions are constrained using an inverse modeling technique and satellite-based AOD observations. Simulations turning on and off fire emissions reveal smoke presence in all tornado outbreaks being studied and show an increase in aerosol number concentrations due to smoke. However, the likelihood of occurrence and intensification of tornadoes is higher due to smoke only in cases where cloud droplet number concentration in low level clouds increases considerably in a way that modifies the environmental conditions where the tornadoes are formed (shallower cloud bases and higher low-level wind shear). Smoke absorption and vertical extent also play a role, with smoke absorption at cloud-level tending to burn-off clouds and smoke absorption above clouds resulting in an increased capping inversion. Comparing these and WRF-Chem simulations configured with a more complex representation of aerosol size and composition and different optical properties, microphysics and activation schemes, we find similarities in terms of the simulated aerosol optical depths and aerosol impacts on near-storm environments. This provides reliability on the aerosol-aware microphysics scheme as a less computationally expensive alternative to WRF-Chem for its use in applications such as NWP and cloud-resolving simulations.

Assessment of Biomass Burning Smoke Influence on Environmental Conditions for Multi-Year Tornado Outbreaks by Combining Aerosol-Aware Microphysics and Fire Emission Constraints

NASA Technical Reports Server (NTRS)

Saide, Pablo E.; Thompson, Gregory; Eidhammer, Trude; Da Silva, Arlindo M.; Pierce, R. Bradley; Carmichael, Gregory R.

2016-01-01

We use the WRF system to study the impacts of biomass burning smoke from Central America on several tornado outbreaks occurring in the US during spring. The model is configured with an aerosol-aware microphysics parameterization capable of resolving aerosol-cloud-radiation interactions in a cost-efficient way for numerical weather prediction (NWP) applications. Primary aerosol emissions are included and smoke emissions are constrained using an inverse modeling technique and satellite-based AOD observations. Simulations turning on and off fire emissions reveal smoke presence in all tornado outbreaks being studied and show an increase in aerosol number concentrations due to smoke. However, the likelihood of occurrence and intensification of tornadoes is higher due to smoke only in cases where cloud droplet number concentration in low level clouds increases considerably in a way that modifies the environmental conditions where the tornadoes are formed (shallower cloud bases and higher low-level wind shear). Smoke absorption and vertical extent also play a role, with smoke absorption at cloud-level tending to burn-off clouds and smoke absorption above clouds resulting in an increased capping inversion. Comparing these and WRF-Chem simulations configured with a more complex representation of aerosol size and composition and different optical properties, microphysics and activation schemes, we find similarities in terms of the simulated aerosol optical depths and aerosol impacts on near-storm environments. This provides reliability on the aerosol-aware microphysics scheme as a less computationally expensive alternative to WRFChem for its use in applications such as NWP and cloud-resolving simulations.

In search of discernible infrasound emitted by numerically simulated tornadoes

NASA Astrophysics Data System (ADS)

Schecter, David A.

2012-09-01

The comprehensive observational study of Bedard (2005) provisionally found that the infrasound of a tornado is discernible from the infrasound of generic cloud processes in a convective storm. This paper discusses an attempt to corroborate the reported observations of distinct tornado infrasound with numerical simulations. Specifically, this paper investigates the infrasound of an ordinary tornado in a numerical experiment with the Regional Atmospheric Modeling System, customized to simulate acoustic phenomena. The simulation has no explicit parameterization of microphysical cloud processes, but creates an unsteady tornado of moderate strength by constant thermal forcing in a rotational environment. Despite strong fluctuations in the lower corner flow and upper outflow regions, a surprisingly low level of infrasound is radiated by the vortex. Infrasonic pressure waves in the 0.1 Hz frequency regime are less intense than those which could be generated by core-scale vortex Rossby (VR) waves of modest amplitude in similar vortices. Higher frequency infrasound is at least an order of magnitude weaker than expected based on infrasonic observations of tornadic thunderstorms. Suppression of VR waves (and their infrasound) is explained by the gradual decay of axial vorticity with increasing radius from the center of the vortex core. Such non-Rankine wind-structure is known to enable the rapid damping of VR waves by inviscid mechanisms, including resonant wave-mean flow interaction and "spiral wind-up" of vorticity. Insignificant levels of higher frequency infrasound may be due to oversimplifications in the computational setup, such as the neglect of thermal fluctuations caused by phase transitions of moisture in vigorous cloud turbulence.

Finding Light at the End of the Funnel: Working with Child Survivors of the Andover Tornado.

ERIC Educational Resources Information Center

McDougall Herl, Tamara Kay

1992-01-01

Presents some guidelines for art activities that teachers can use to help their students work through their feelings following a natural disaster. Includes some personal observations of art expressions created after a tornado struck. Explains how art produced by students in response to catastrophe seemed to fall into three major categories:…

Talking about Twisters: Relations between Mothers' and Children's Contributions to Conversations about a Devastating Tornado

ERIC Educational Resources Information Center

Bauer, Patricia J.; Burch, Melissa M.; Van Abbema, Dana L.; Ackil, Jennifer K.

2007-01-01

Mother-child dyads who experienced a devastating tornado talked about the storm and about two affectively more positive or neutral events at each of two time points: 4 months and 10 months after the storm. The conversations were analyzed to determine whether mothers and/or children's contributions differed as a function of event type and whether…

Pedologic and geomorphic impacts of a tornado blowdown event in a mixed pine-hardwood forest

Treesearch

Jonathan D. Phillips; Daniel A. Marion; Alice V. Turkington

2008-01-01

Biomechanical effects of trees on soils and surface processes may be extensive in forest environments. Two blowdown sites caused by a November 2005 tornado in the Ouachita National Forest, Arkansas allowed a case study examination of bioturbation associated with a specific forest blowdown event, as well as detailed examination of relationships between tree root systems...

Tornado Emergency Readiness Planning for Schools.

ERIC Educational Resources Information Center

Wisconsin State Dept. of Public Instruction, Madison.

A place of safe refuge in the event of violent natural forces or a tornado should be included in the design of all new school buildings. Existing a school buildings should be analyzed by the architect, contractor, or engineer to determine if a safe place exists or if one can be readily adapted. Most criteria for fallout shelters are the same for…

Tornado detection data reduction and analysis

NASA Technical Reports Server (NTRS)

Davisson, L. D.

1977-01-01

Data processing and analysis was provided in support of tornado detection by analysis of radio frequency interference in various frequency bands. Sea state determination data from short pulse radar measurements were also processed and analyzed. A backscatter simulation was implemented to predict radar performance as a function of wind velocity. Computer programs were developed for the various data processing and analysis goals of the effort.

Okla. Tornado Renews Debate on Storm Safety

ERIC Educational Resources Information Center

Shah, Nirvi

2013-01-01

As soon as the winds that left seven students in Moore, Okla., dead last month had calmed, and more storms blew through the same area less than two weeks later, questions about the safety of schools in a region labeled Tornado Alley rose amid the rubble. While better design of new schools and thorough emergency training and practice may be in…

Perceptions and Experiences of K-12 Educational Leaders in Response to the 27 April 2011 Tornadoes

ERIC Educational Resources Information Center

Bishop, William E.; Fifolt, Matthew; Peters, Gary B.; Gurley, D. Keith; Collins, Loucrecia

2015-01-01

The purpose of this phenomenological study was to capture first-hand accounts of K-12 educational leaders whose school districts were directly affected by the deadly 27 April 2011 tornadoes in rural Alabama, USA. This study was framed by the literature base of leadership; specifically crisis leadership and resilience theory. Findings are organised…

Storm Prediction Center Today's Storm Reports

Science.gov Websites

)(?) Time Location County State Lat Lon Comments 2056 7 N BUFORD ALBANY WY 4121 10530 TORNADO SPOTTED NORTH 4236 10503 ON THE GROUND AT THIS TIME. (CYS) 2215 15 N CHEYENNE LARAMIE WY 4136 10479 TORNADO MOVING TOWARDS I-25 BETWEEN MM 25 AND 35. (CYS) Hail Reports (CSV) (Raw Hail CSV)(?) Time Size Location County

Tornado Safety (Online Tornado FAQ)

Science.gov Websites

, nursing homes, hospitals, sports arenas, stadiums, mobile home communities and offices should have a ; you could be trapped in them if the power is lost. In a mobile home:Get out! Even if your home is tied destroy even tied-down mobile homes; and it is best not to play the low odds that yours will make it. This

Tornado-like transport in a magnetized plasma

NASA Astrophysics Data System (ADS)

Poulos, Matthew; van Compernolle, Bart; Morales, George

2017-10-01

Recent heat transport experiments conducted in the LAPD device at UCLA in which avalanche events have been previously documented have also lead to the identification of a new tornado-like transport phenomenon. These tornados occur much earlier than the avalanches events, essentially in the interval following the application of the bias voltage that causes the injection of an electron beam from a ring-shaped LaB6 cathode into the afterglow of a cold, magnetized plasma. The tornados exhibit a low-frequency (4 kHz) (much lower than drift-waves), spiraling, global eigenmode whose transient behavior is responsible for significant radial transport well outside the heated region. Detailed experimental observations are compared with a Braginskii transport code that includes the effects of ExB convection induced by the spiraling global eigenmode. New insights are gained into the necessary modifications of classical transport to accurately simulate the spiraling effects and the possible interaction with avalanches. This work is supported by the NSF/DOE partnership in basic plasma science and engineering, Grant Number 1619505, and is performed at the Basic Plasma Science Facility, sponsored jointly by DOE and NSF. Sponsored by DOE/NSF at BaPSF and NSF 1619505.

Cloud-to-Ground Lightning Characteristics of a Major Tropical Cyclone Tornado Outbreak

NASA Technical Reports Server (NTRS)

McCaul, Eugene W., Jr.; Buechler, Dennis; Goodman, Steven J.

1999-01-01

A comprehensive analysis has been conducted of the cloud-to-ground lightning activity occurring within a landfalling tropical cyclone that produced an outbreak of strong and damaging tornadoes. Radar data indicate that 12 convective cells were responsible for 29 tornadoes, several of which received an F3 intensity rating, in the southeastern United States on 16 August 1994 within the remnants of Tropical Storm Beryl. Of these 12 tornadic storms, the most active cell produced 315 flashes over a 5.5 hour period, while the other storms were less active. Three tornadic storms failed to produce any CG lightning at all. In general, the tornadic storms were more active electrically than other non-tornadic cells within Beryl's remnants, although the flash rates were rather modest by comparison with significant midlatitude severe storm events. Very few positive polarity flashes were found in the Beryl outbreak. During some of the stronger tornadoes, CG flash rates in the parent storms showed sharp transient decreases. Doppler radar data suggest the stronger tornadic storms were small supercells, and the lightning data indicate these storms exhibited lightning characteristics similar to those found in heavy-precipitation supercell storms.

Epidemiology of tornado destruction in rural northern Bangladesh: risk factors for death and injury.

PubMed

Sugimoto, Jonathan D; Labrique, Alain B; Ahmad, Salahuddin; Rashid, Mahbubur; Shamim, Abu Ahmed; Ullah, Barkat; Klemm, Rolf D W; Christian, Parul; West, Keith P

2011-04-01

The epidemiology of tornado-related disasters in the developing world is poorly understood. An August 2005 post-tornado cohort study in rural Bangladesh identified elevated levels of death and injury among the elderly (≥ 60 years of age) (adjusted odds ratio (AOR) = 8.9 (95 per cent confidence interval (CI): 3.9-20.2) and AOR = 1.6 (95 per cent CI: 1.4-1.8), respectively), as compared to 15-24 year-olds, and among those outdoors versus indoors during the tornado (AOR = 10.4 (95 per cent CI: 5.5-19.9) and AOR = 6.6 (95 per cent CI: 5.8-7.5), respectively). Females were 1.24 times (95 per cent CI: 1.15-1.33) more likely to be injured than males. Elevated risk of injury was significantly associated with structural damage to the house and tin construction materials. Seeking treatment was protective against death among the injured, odds ratio = 0.08 (95 per cent CI: 0.03-0.21). Further research is needed to develop injury prevention strategies and to address disparities in risk between age groups and between men and women. © 2011 The Author(s). Disasters © Overseas Development Institute, 2011.

Tornado-Like Evolution of A Kink-Unstable Solar Prominence

NASA Astrophysics Data System (ADS)

Wang, W.; Liu, R.; Wang, Y.

2016-12-01

We report on the tornado-like evolution of a quiescent prominence on 2014 November 1. The evolution started with a slow rise of the eastern section of the prominence into an arch-shaped structure as high as 150 Mm above the limb, and then the arch experienced a moderate, left-handed writhing. Following the writhing, the originally dark prominence material became in emission in the Fe IX 171 °A passband, and a braiding structure appeared at the eastern edge of the writhing prominence body, whose unraveling process was associated with a transient brightening in EUV and apparently contributed to the formation of a curtain-like structure (CLS), which consisted of myriads of thread-like loops rotating counterclockwise about the vertical if viewed from above. Material sliding along these loops landed outside of the prominence channel. The tornado was eventually disintegrated and the remaining material flew along a lefthanded helical path of approximately a full turn, as confirmed through stereoscopic reconstruction, into the cavity of the stable, western section of the prominence. We suggest that the tornado-like evolution of the prominence was regulated by the helical kink instability, and that the CLS forms through magnetic reconnections between the flux-rope flux and the overlying flux.

Tornado-like Evolution of a Kink-unstable Solar Prominence

NASA Astrophysics Data System (ADS)

Wang, Wensi; Liu, Rui; Wang, Yuming

2017-01-01

We report on the tornado-like evolution of a quiescent prominence on 2014 November 1. The eastern section of the prominence first rose slowly, transforming into an arch-shaped structure as high as ˜150 Mm above the limb; the arch then writhed moderately in a left-handed sense, while the original dark prominence material emitted in the Fe ix 171 Å passband, and a braided structure appeared at the eastern edge of the warped arch. The unraveling of the braided structure was associated with a transient brightening in the EUV and apparently contributed to the formation of a curtain-like structure (CLS). The CLS consisted of myriad thread-like loops rotating counterclockwise about the vertical if viewed from above. Heated prominence material was observed to slide along these loops and land outside the filament channel. The tornado eventually disintegrated and the remaining material flew along a left-handed helical path constituting approximately a full turn, as corroborated through stereoscopic reconstruction, into the cavity of the stable, western section of the prominence. We suggest that the tornado-like evolution of the prominence was governed by the helical kink instability, and that the CLS formed through magnetic reconnections between the prominence field and the overlying coronal field.

Injuries and risk factors for injuries from the 29 May 1982 tornado, Marion, Illinois.

PubMed

Duclos, P J; Ing, R T

1989-03-01

On 29 May 1982, a tornado struck Marion, Illinois. As a result, ten people were killed, 38 were hospitalized, and 196 were examined in hospital emergency rooms. In order to describe injuries and to identify risk factors that might have increased or reduced the risk of injuries, we (1) conducted a telephone survey of all persons we could identify who were in the path of the tornado and (2) reviewed the emergency room logs and records and admission files of hospitals that provided initial care. Overall, 19.3% of people who were in the path of the tornado were injured during the impact. Only 39.0% of people examined in emergency rooms were injured as a direct result of the impact. The remainder were injured while rescuing, cleaning up, or just walking in the disaster area. Behaviours that were most protective were being in a house on the lowest floor, staying underground in a basement, protecting one's body with something like a blanket, and staying away from windows. Neither lying down nor opening doors or windows seemed to decrease the risk of being injured. Our results emphasize the need for early warnings and public education about protective behaviours.

Atmospheric structure prior to tornadoes as derived from proximity and precedent upper-air soundings, covering the period April 1977-June 1979

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taylor, G.E.; Darkow, G.L.

1982-05-01

The uniqueness of the thermodynamic and dynamic structure of the atmosphere in the area of imminent tornado bearing storm development is analyzed by comparing 115 tornado proximity soundings with upper air soundings made at the same location 6 and 12 hours earlier (precedent soundings) and with soundings made simultaneously at neighboring upper air stations. The comparisons suggest that both the proximity station and the neighboring station upstream with respect to the mean flow in the low level moist air display very similar degrees of hydrostatic and potential-convective instability by late afternoon. The principal difference is in the wind profiles atmore » the two locations. The tornado proximity station displays significantly stronger wind speeds above 1 km with the most striking difference being in the vertical shear of the wind in the layer from 1 to 3 km above ground level. In this layer the winds at the proximity station show an average increase of about 3 m sec/sup -1/ while the upstream, non-tornadic, station shows a slight decrease of wind speed with height.« less

Design guidelines for wind-resistant structures

DOE Office of Scientific and Technical Information (OSTI.GOV)

McDonald, J.R.; Mehta, K.C.; Minor, J.E.

1975-06-01

The purpose of this document is to prescribe criteria and to provide guidance for professional personnel who are involved in the design and evaluation of buildings and structures to resist tornadoes and extreme winds at the Oak Ridge, Tennessee, Portsmouth, Ohio, and Paducah, Kentucky, Plant Sites. The scope of the document covers loads due to extreme winds and tornadoes. Other loading conditions such as dead, live, or earthquake loads shall be considered as prescribed by the Union Carbide Corporation. In Section II the method for determining the maximum design windspeed for any specified level of risk is described. The straightmore » wind and tornado parameters are then deduced from the value of maximum design windspeed. The three types of tornado and extreme wind loads (aerodynamic, atmospheric pressure change and missiles) are treated in Sections III, IV, and V, respectively. Appropriate load combinations are defined in Section VI. The final section contains several examples showing how the design guidelines are used to determine appropriate design wind pressures. A description of the computer program used to predict missile accelerations, velocities and trajectories is contained in Appendix A. Additional design examples are provided in Appendix B.« less

The Alberta and Xenia tornados: how two hospitals handled hundreds of victims under trying conditions.

PubMed

2000-11-01

Tornadoes rarely hit in areas where there are many hospitals. Two of the worst in recent years caused numerous casualties in a rural area of Canada and in a small city in Ohio, taxing the capabilities of the nearby hospitals involved. This report provides details on how they handled these disasters and what they learned from their experience.

Regeneration response to tornado and salvage harvesting in a bottomland forest

Treesearch

John L. Nelson; John W. Groninger; Loretta L. Battaglia; Charles M. Ruffner

2010-01-01

A direct hit from an F4 tornado on May 2003, followed by a partial salvage logging operation at Mermet Lake State Conservation Area on the Ohio River bottoms of southern IL have provided a rare opportunity to assess the responses of a bottomland hardwood forest to severe wind and soil disturbances. The study area encompasses 700 acres and is representative of many...