Multi-Scale Remote Sensing of Tornado Effects J
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The Fujita Scale Is Used to Rate the Intensity of a Tornado by Examining the Damage Caused by the Tornado After It Has Passed Over a Man-Made Structure
The Fujita Scale is used to rate the intensity of a tornado by examining the damage caused by the tornado after it has passed over a man-made structure. The "Percentage of All Tornadoes 1950- 1994" pie chart reveals that the vast majority of tornadoes are either weak or do damage that can only be attributed to a weak tornado. Only a small percentage of tornadoes can be correctly classed as violent. Such a chart became possible only after the acceptance of the Fujita Scale as the official classification system for tornado damage. It is quite possible that an even higher percentage of all tornadoes are weak. Each year the National Weather Service documents about 1000 tornado touchdowns in the United States. There is evidence that 1000 or more additional weak tornadoes may occur each year and go completely undocumented. The "Percentage of Tornado-Related Deaths 1950-1994" pie chart shows that while violent tornadoes are few in number, they cause a very high percentage of tornado-related deaths. The Tornado Project has analyzed data prior to 1950, and found that the percentage of deaths from violent tornadoes was even greater in the past. This is because the death tolls prior to the introduction of the forecasting/awareness programs were enormous: 695 dead(Missouri-Illinois-Indiana, March 18, 1925); 317 dead(Natchez, Mississippi, May 7, 1840);.255 dead(St. Louis, Missouri and East St. Louis, Illinois, May 27, 1896); 216 dead(Tupelo, Mississippi, April 5, 1936); 203 dead(Gainesville, GA, April 6, 1936). In more recent times, no single tornado has killed more than 50 people since 1971. -
Community at the Center of the Storm | 87
ABSTRACT This article is based on a Community at the keynote presentation delivered at the Alabama Poverty Project Lifetime of Learning Summit at the University of Center of the Storm Montevallo on September 30, 2011. Conference organizers asked for the Marybeth Lima perspective of a survivor of a significant natural disaster, for information Before hurricane Katrina, I was steady and regarding Louisiana’s recovery from confident in my job as an associate professor in the hurricanes Katrina and Rita in the short- department of biological & agricultural engineering at and long-term, and for advice on re- LSU. I had been doing service-learning since 1998, building and recovery within the and I worked very closely with the staff from the framework of poverty eradication. This Center for Community Engagement, Learning and paper details the author’s experiences in Leadership, or CCELL. In working closely with CCELL and with my community, I had developed the LSU the 2005 hurricanes and lessons learned Community Playground Project. through subsequent community- I teach a required, first-year biological engagement efforts. engineering design course in which my students partner with local public elementary schools to work with the true experts at play, the children at the schools, to develop dream playground designs at those schools. My class consists of two to three sections of students, and each section is assigned a separate public school. College students work collaboratively in teams of three to four people with the elementary school students, teachers, and school administrators, and sometimes parents or school improvement teams, to develop playground designs. -
What Are We Doing with (Or To) the F-Scale?
5.6 What Are We Doing with (or to) the F-Scale? Daniel McCarthy, Joseph Schaefer and Roger Edwards NOAA/NWS Storm Prediction Center Norman, OK 1. Introduction Dr. T. Theodore Fujita developed the F- Scale, or Fujita Scale, in 1971 to provide a way to compare mesoscale windstorms by estimating the wind speed in hurricanes or tornadoes through an evaluation of the observed damage (Fujita 1971). Fujita grouped wind damage into six categories of increasing devastation (F0 through F5). Then for each damage class, he estimated the wind speed range capable of causing the damage. When deriving the scale, Fujita cunningly bridged the speeds between the Beaufort Scale (Huler 2005) used to estimate wind speeds through hurricane intensity and the Mach scale for near sonic speed winds. Fujita developed the following equation to estimate the wind speed associated with the damage produced by a tornado: Figure 1: Fujita's plot of how the F-Scale V = 14.1(F+2)3/2 connects with the Beaufort Scale and Mach number. From Fujita’s SMRP No. 91, 1971. where V is the speed in miles per hour, and F is the F-category of the damage. This Amazingly, the University of Oklahoma equation led to the graph devised by Fujita Doppler-On-Wheels measured up to 318 in Figure 1. mph flow some tens of meters above the ground in this tornado (Burgess et. al, 2002). Fujita and his staff used this scale to map out and analyze 148 tornadoes in the Super 2. Early Applications Tornado Outbreak of 3-4 April 1974. -
Human Vulnerability to Tornadoes in the United States Is Highest In
1 Human vulnerability to tornadoes in the United States is highest in 2 urbanized areas of the Mid South ∗ 3 James B. Elsner and Tyler Fricker 4 Florida State University, Tallahassee, Florida ∗ 5 Corresponding author address: James B. Elsner, Department of Geography, Florida State Univer- 6 sity, 113 Collegiate Loop, Tallahassee, FL 32301. 7 E-mail: [email protected] Generated using v4.3.2 of the AMS LATEX template 1 ABSTRACT 8 Risk factors for tornado casualties are well known. Less understood is how 9 and to what degree these factors, after controlling for strength and the number 10 of people affected, vary over space and time. Here we fit models to casualty 11 counts from all casualty-producing tornadoes during the period 1995–2016 in 12 order to quantify the interactions between population and energy on casualty 13 (deaths plus injuries) rates. Results show that the more populated areas of the 14 Mid South are substantially and significantly more vulnerable to casualties 15 than elsewhere in the country. In this region casualty rates are significantly 16 higher on the weekend. Night and day casualty rates are similar regardless 17 of where the tornadoes occur. States with a high percentage of older people 18 (65+) tend to have greater vulnerability perhaps related to less agility and 19 fewer communication options. 2 20 1. Introduction 21 Nearly one fifth of all natural-hazards fatalities in the United States are the direct result of tor- 22 nadoes (National Oceanic and Atmospheric Administration 2015). A tornado that hits a city is 23 capable of inflicting hundreds or thousands of casualties. -
19.4 Updated Mobile Radar Climatology of Supercell
19.4 UPDATED MOBILE RADAR CLIMATOLOGY OF SUPERCELL TORNADO STRUCTURES AND DYNAMICS Curtis R. Alexander* and Joshua M. Wurman Center for Severe Weather Research, Boulder, Colorado 1. INTRODUCTION evolution of angular momentum and vorticity near the surface in many of the tornado cases is also High-resolution mobile radar observations of providing some insight into possible modes of supercell tornadoes have been collected by the scale contraction for tornadogenesis and failure. Doppler On Wheels (DOWs) platform between 1995 and present. The result of this ongoing effort 2. DATA is a large observational database spanning over 150 separate supercell tornadoes with a typical The DOWs have collected observations in and data resolution of O(50 m X 50 m X 50 m), near supercell tornadoes from 1995 through 2008 updates every O(60 s) and measurements within including the fields of Doppler velocity, received 20 m of the surface (Wurman et al. 1997; Wurman power, normalized coherent power, radar 1999, 2001). reflectivity, coherent reflectivity and spectral width (Wurman et al. 1997). Stemming from this database is a multi-tiered effort to characterize the structure and dynamics of A typical observation is a four-second quasi- the high wind speed environments in and near horizontal scan through a tornado vortex. To date supercell tornadoes. To this end, a suite of there have been over 10000 DOW observations of algorithms is applied to the radar tornado supercell tornadoes comprising over 150 individual observations for quality assurance along with tornadoes. detection, tracking and extraction of kinematic attributes. Data used for this study include DOW supercell tornado observations from 1995-2003 comprising The integration of observations across tornado about 5000 individual observations of 69 different cases in the database is providing an estimate of mesocyclone-associated tornadoes. -
3.2 an Evaluation of Tornado Intensity Using Velocity and Strength Attributes from the Wsr-88D Mesocyclone Detection Algorithm
3.2 AN EVALUATION OF TORNADO INTENSITY USING VELOCITY AND STRENGTH ATTRIBUTES FROM THE WSR-88D MESOCYCLONE DETECTION ALGORITHM Darrel M. Kingfield*,1,2, James G. LaDue3, and Kiel L. Ortega1,2 1Cooperative Institute for Mesoscale Meteorological Studies (CIMMS), Norman, OK 2NOAA/OAR/National Severe Storms Laboratory (NSSL), Norman, OK 3NOAA/NWS/OCWWS/Warning Decision Training Branch (WDTB), Norman, OK 1. INTRODUCTION undergone several improvements since these studies, including the integration of super-resolution data. National Weather Service (NWS) service Super-resolution data (Torres and Curtis, 2007) at the assessments following the 2011 April 27 southeast split-cut elevations reduces the effective beamwidth to US tornado outbreak, and the 2011 May 22 Joplin 1.02 from the legacy 1.38 , allowing for vortex tornado found that the population failed to personalize signatures⁰ to be resolved at longer⁰ ranges from the the potential severity of the tornadoes for which they radar (Brown et al. 2002; Brown et al. 2005). In this were warned. The lack of specific information paper, we investigate how the MDA output correlates contained within the warnings has been cited as a to maximum intensity found in a tornado path. major reason why more action was not taken (NOAA, 2011a, 2011b). As a result, a number of meetings 2. DATA & METHODS amongst government, the private and the academic sectors have begun to formulate a plan to improve 2.1 Acquisition & Playback impact-based warning services. In fact, this is the number one goal of the Weather Ready Nation The initial tornado track dataset was composed initiative within the NWS (NOAA, 2012). -
Observations and Laboratory Simulations of Tornadoes in Complex Topographical Regions Christopher D
Iowa State University Capstones, Theses and Graduate Theses and Dissertations Dissertations 2012 Observations and Laboratory Simulations of Tornadoes in Complex Topographical Regions Christopher D. Karstens Iowa State University Follow this and additional works at: https://lib.dr.iastate.edu/etd Part of the Atmospheric Sciences Commons, and the Meteorology Commons Recommended Citation Karstens, Christopher D., "Observations and Laboratory Simulations of Tornadoes in Complex Topographical Regions" (2012). Graduate Theses and Dissertations. 12778. https://lib.dr.iastate.edu/etd/12778 This Dissertation is brought to you for free and open access by the Iowa State University Capstones, Theses and Dissertations at Iowa State University Digital Repository. It has been accepted for inclusion in Graduate Theses and Dissertations by an authorized administrator of Iowa State University Digital Repository. For more information, please contact [email protected]. Observations and laboratory simulations of tornadoes in complex topographical regions by Christopher Daniel Karstens A dissertation submitted to the graduate faculty in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Major: Meteorology Program of Study Committee: William A. Gallus, Jr., Major Professor Partha P. Sarkar Bruce D. Lee Catherine A. Finley Raymond W. Arritt Xiaoqing Wu Iowa State University Ames, Iowa 2012 Copyright © Christopher Daniel Karstens, 2012. All rights reserved. ii TABLE OF CONTENTS LIST OF FIGURES .............................................................................................. -
ESSENTIALS of METEOROLOGY (7Th Ed.) GLOSSARY
ESSENTIALS OF METEOROLOGY (7th ed.) GLOSSARY Chapter 1 Aerosols Tiny suspended solid particles (dust, smoke, etc.) or liquid droplets that enter the atmosphere from either natural or human (anthropogenic) sources, such as the burning of fossil fuels. Sulfur-containing fossil fuels, such as coal, produce sulfate aerosols. Air density The ratio of the mass of a substance to the volume occupied by it. Air density is usually expressed as g/cm3 or kg/m3. Also See Density. Air pressure The pressure exerted by the mass of air above a given point, usually expressed in millibars (mb), inches of (atmospheric mercury (Hg) or in hectopascals (hPa). pressure) Atmosphere The envelope of gases that surround a planet and are held to it by the planet's gravitational attraction. The earth's atmosphere is mainly nitrogen and oxygen. Carbon dioxide (CO2) A colorless, odorless gas whose concentration is about 0.039 percent (390 ppm) in a volume of air near sea level. It is a selective absorber of infrared radiation and, consequently, it is important in the earth's atmospheric greenhouse effect. Solid CO2 is called dry ice. Climate The accumulation of daily and seasonal weather events over a long period of time. Front The transition zone between two distinct air masses. Hurricane A tropical cyclone having winds in excess of 64 knots (74 mi/hr). Ionosphere An electrified region of the upper atmosphere where fairly large concentrations of ions and free electrons exist. Lapse rate The rate at which an atmospheric variable (usually temperature) decreases with height. (See Environmental lapse rate.) Mesosphere The atmospheric layer between the stratosphere and the thermosphere. -
Tornadoes & Downburst
TORNADOES & DOWNBURST TORNADOES • A devastating F5 tornado about 200 meters wide plows through Hesston, Kansas, on March 13, 1990, leaving almost 300 people homeless and 13 injured. • Total destruction caused by an F5 tornado that devastated parts of Oklahoma on May 3, 1999. • A tornado is a violently rotating (usually counterclockwise in the northern hemisphere) column of air descending from a thunderstorm and in contact with the ground. Although tornadoes are usually brief, lasting only a few minutes, they can sometimes last for more than an hour and travel several miles causing considerable damage. In a typical year about 1000 tornadoes will strike the United States. The peak of the tornado season is April through June and more tornadoes strike the central United States than any other place in the world. This area has been nicknamed "tornado alley." Most tornadoes are spawned from supercell thunderstorms. Supercell thunderstorms are characterized by a persistent rotating updraft and form in environments of strong vertical wind shear. Wind shear is the change in wind speed and/or direction with height. • Tornadoes are natures most destructive weather hazard. Annual Number of Tornadoes per State (upper number) • Tornado incidence by state. The upper figure shows the number of tornadoes reported by each state during a 25-year period. The lower figure is the average annual number of tornadoes per 10,000 square miles. The darker the shading, the greater the frequency of tornadoes. • Average number of tornadoes during each month in the United States. Fujita Scale F0-F1 Fujita scale is a measure of tornado intensity Winds 60 - 115 mph quantified through a subjective analysis of relating tornadic damage to wind speed. -
The Year That Shook the Rich: a Review of Natural Disasters in 2011
THE YEAR THAT SHOOK THE RICH: A REVIEW OF NATURAL DISASTERS IN 2011 The Brookings Institution – London School of Economics Project on Internal Displacement March 2012 Design: [email protected] Cover photo: © Thinkstock.com Back cover photos: left / © Awcnz62 | Dreamstime.com; right / © IOM 2011 - MPK0622 (Photo: Chris Lom) THE YEAR THAT SHOOK THE RICH: A REVIEW OF NATURAL DISASTERS IN 2011 By Elizabeth Ferris and Daniel Petz March 2012 PUBLISHED BY: THE BROOKINGS INSTITUTION – LONDON SCHOOL OF ECONOMICS PROJECT ON INTERNAL DISPLACEMENT Bangkok, Thailand — Severe monsoon floods, starting in late July 2011, affected millions of people. A truck with passengers aboard drives through a heavily flooded street. Photo: UN/Mark Garten TABLE OF CONTENTS Acronyms ................................................................................................................................. vi Foreword ................................................................................................................................. ix Executive Summary ................................................................................................................. xi Introduction .............................................................................................................................. xv Chapter 1 The Year that Shook the Rich ...................................................... 1 Section 1 Disasters in the “Rich” World, Some Numbers ............................................ 5 Section 2 Japan: The Most Expensive Disaster -
1 International Approaches to Tornado Damage and Intensity Classification International Association of Wind Engineers
International Approaches to Tornado Damage and Intensity Classification International Association of Wind Engineers (IAWE), International Tornado Working Group 2017 June 6, DRAFT FINAL REPORT 1. Introduction Tornadoes are one of the most destructive natural Hazards on Earth, with occurrences Having been observed on every continent except Antarctica. It is difficult to determine worldwide occurrences, or even the fatalities or losses due to tornadoes, because of a lack of systematic observations and widely varying approacHes. In many jurisdictions, there is not any tracking of losses from severe storms, let alone the details pertaining to tornado intensity. Table 1 provides a summary estimate of tornado occurrence by continent, with details, wHere they are available, for countries or regions Having more than a few observations per year. Because of the lack of systematic identification of tornadoes, the entries in the Table are a mix of verified tornadoes, reports of tornadoes and climatological estimates. Nevertheless, on average, there appear to be more than 1800 tornadoes per year, worldwide, with about 70% of these occurring in North America. It is estimated that Europe is the second most active continent, with more than 240 per year, and Asia third, with more than 130 tornadoes per year on average. Since these numbers are based on observations, there could be a significant number of un-reported tornadoes in regions with low population density (CHeng et al., 2013), not to mention the lack of systematic analysis and reporting, or the complexity of identifying tornadoes that may occur in tropical cyclones. Table 1 also provides information on the approximate annual fatalities, althougH these data are unavailable in many jurisdictions and could be unreliable. -
A Background Investigation of Tornado Activity Across the Southern Cumberland Plateau Terrain System of Northeastern Alabama
DECEMBER 2018 L Y Z A A N D K N U P P 4261 A Background Investigation of Tornado Activity across the Southern Cumberland Plateau Terrain System of Northeastern Alabama ANTHONY W. LYZA AND KEVIN R. KNUPP Department of Atmospheric Science, Severe Weather Institute–Radar and Lightning Laboratories, Downloaded from http://journals.ametsoc.org/mwr/article-pdf/146/12/4261/4367919/mwr-d-18-0300_1.pdf by NOAA Central Library user on 29 July 2020 University of Alabama in Huntsville, Huntsville, Alabama (Manuscript received 23 August 2018, in final form 5 October 2018) ABSTRACT The effects of terrain on tornadoes are poorly understood. Efforts to understand terrain effects on tornadoes have been limited in scope, typically examining a small number of cases with limited observa- tions or idealized numerical simulations. This study evaluates an apparent tornado activity maximum across the Sand Mountain and Lookout Mountain plateaus of northeastern Alabama. These plateaus, separated by the narrow Wills Valley, span ;5000 km2 and were impacted by 79 tornadoes from 1992 to 2016. This area represents a relative regional statistical maximum in tornadogenesis, with a particular tendency for tornadogenesis on the northwestern side of Sand Mountain. This exploratory paper investigates storm behavior and possible physical explanations for this density of tornadogenesis events and tornadoes. Long-term surface observation datasets indicate that surface winds tend to be stronger and more backed atop Sand Mountain than over the adjacent Tennessee Valley, potentially indicative of changes in the low-level wind profile supportive to storm rotation. The surface data additionally indicate potentially lower lifting condensation levels over the plateaus versus the adjacent valleys, an attribute previously shown to be favorable for tornadogenesis.