Tornado Basics
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Wind Speed-Damage Correlation in Hurricane Katrina
JP 1.36 WIND SPEED-DAMAGE CORRELATION IN HURRICANE KATRINA Timothy P. Marshall* Haag Engineering Co. Dallas, Texas 1. INTRODUCTION According to Knabb et al. (2006), Hurricane Katrina Mehta et al. (1983) and Kareem (1984) utilized the was the costliest hurricane disaster in the United States to concept of wind speed-damage correlation after date. The hurricane caused widespread devastation from Hurricanes Frederic and Alicia, respectively. In essence, Florida to Louisiana to Mississippi making a total of three each building acts like an anemometer that records the landfalls before dissipating over the Ohio River Valley. wind speed. A range of failure wind speeds can be The storm damaged or destroyed many properties, determined by analyzing building damage whereas especially near the coasts. undamaged buildings can provide upper bounds to the Since the hurricane, various agencies have conducted wind speeds. In 2006, WSEC developed a wind speed- building damage assessments to estimate the wind fields damage scale entitled the EF-scale, named after the late that occurred during the storm. The National Oceanic Dr. Ted Fujita. The author served on this committee. and Atmospheric Administration (NOAA, 2005a) Wind speed-damage correlation is useful especially conducted aerial and ground surveys and published a when few ground-based wind speed measurements are wind speed map. Likewise, the Federal Emergency available. Such was the case in Hurricane Katrina when Management Agency (FEMA, 2006) conducted a similar most of the automated stations failed before the eye study and produced another wind speed map. Both reached the coast. However, mobile towers were studies used a combination of wind speed-damage deployed by Texas Tech University (TTU) at Slidell, LA correlation, actual wind measurements, as well as and Bay St. -
Rotating Storms: Supercells, Tornadoes, and Tropical Storms
RotatingRotating Storms:Storms: SupercellsSupercells,, Tornadoes,Tornadoes, andand TropicalTropical StormsStorms AT 351 Lab 12 April 14, 2008 SupercellsSupercells ! Characterized by rotating updrafts (called a mesocyclone) ! Differ from multicell cluster because smaller updrafts merge into a main rotated updraft rather than developing separate and competing cells ! Can persist for 12 hours and travel hundreds of miles ! Forms in environments of strong winds aloft ! Winds veer with height from the surface ! Can be classified as either High Precipitation (HP) or Low Precipitation (LP) SupercellSupercell HPHP SupercellsSupercells •Dark rain and hail core •Prolific producers of lightning and flash floods LPLP SupercellsSupercells ! Typically associated with a dry line ! Typically small and lacking in rainfall TornadoesTornadoes ! Formation ! Life Cycle ! Definition ! Types ! Damage ! EF-scale FormationFormation ! We know relatively little about the formation of tornadoes, known as tornadogenesis ! However, we do know the basic steps along the way ! It is the details we are missing, but they are very crucial details VorticityVorticity ! Vorticity is the name we give to a natural spin in the air ! Caused mainly by wind shear ! Just like a pinwheel Non-SupercellNon-Supercell TornadoTornado FormationFormation ! Vertical wind shear crucial VorticityVorticity TiltingTilting ! After horizontal rotation is established, the storm’s updraft works to tilt it upright ! Now the storm has a vertically rotating component SuctionSuction VorticesVortices -
A Study of Synoptic-Scale Tornado Regimes
Garner, J. M., 2013: A study of synoptic-scale tornado regimes. Electronic J. Severe Storms Meteor., 8 (3), 1–25. A Study of Synoptic-Scale Tornado Regimes JONATHAN M. GARNER NOAA/NWS/Storm Prediction Center, Norman, OK (Submitted 21 November 2012; in final form 06 August 2013) ABSTRACT The significant tornado parameter (STP) has been used by severe-thunderstorm forecasters since 2003 to identify environments favoring development of strong to violent tornadoes. The STP and its individual components of mixed-layer (ML) CAPE, 0–6-km bulk wind difference (BWD), 0–1-km storm-relative helicity (SRH), and ML lifted condensation level (LCL) have been calculated here using archived surface objective analysis data, and then examined during the period 2003−2010 over the central and eastern United States. These components then were compared and contrasted in order to distinguish between environmental characteristics analyzed for three different synoptic-cyclone regimes that produced significantly tornadic supercells: cold fronts, warm fronts, and drylines. Results show that MLCAPE contributes strongly to the dryline significant-tornado environment, while it was less pronounced in cold- frontal significant-tornado regimes. The 0–6-km BWD was found to contribute equally to all three significant tornado regimes, while 0–1-km SRH more strongly contributed to the cold-frontal significant- tornado environment than for the warm-frontal and dryline regimes. –––––––––––––––––––––––– 1. Background and motivation As detailed in Hobbs et al. (1996), synoptic- scale cyclones that foster tornado development Parameter-based and pattern-recognition evolve with time as they emerge over the central forecast techniques have been essential and eastern contiguous United States (hereafter, components of anticipating tornadoes in the CONUS). -
A Climatology and Comparison of Parameters for Significant Tornado
106 WEATHER AND FORECASTING VOLUME 27 A Climatology and Comparison of Parameters for Significant Tornado Events in the United States JEREMY S. GRAMS AND RICHARD L. THOMPSON NOAA/NWS/Storm Prediction Center, Norman, Oklahoma DARREN V. SNIVELY Department of Geography, Ohio University, Athens, Ohio JAYSON A. PRENTICE Department of Geological and Atmospheric Sciences, Iowa State University, Ames, Iowa GINA M. HODGES AND LARISSA J. REAMES School of Meteorology, University of Oklahoma, Norman, Oklahoma (Manuscript received 18 January 2011, in final form 30 August 2011) ABSTRACT A sample of 448 significant tornado events was collected, representing a population of 1072 individual tornadoes across the contiguous United States from 2000 to 2008. Classification of convective mode was assessed from radar mosaics for each event with the majority classified as discrete cells compared to quasi- linear convective systems and clusters. These events were further stratified by season and region and com- pared with a null-tornado database of 911 significant hail and wind events that occurred without nearby tornadoes. These comparisons involved 1) environmental variables that have been used through the past 25– 50 yr as part of the approach to tornado forecasting, 2) recent sounding-based parameter evaluations, and 3) convective mode. The results show that composite and kinematic parameters (whether at standard pressure levels or sounding derived), along with convective mode, provide greater discrimination than thermodynamic parameters between significant tornado versus either significant hail or wind events that occurred in the absence of nearby tornadoes. 1. Introduction severe thunderstorms and tornadoes (e.g., Bluestein 1999; Davies-Jones et al. 2001; Wilhelmson and Wicker Severe weather forecasting has evolved considerably 2001). -
Tornado Safety Q & A
TORNADO SAFETY Q & A The Prosper Fire Department Office of Emergency Management’s highest priority is ensuring the safety of all Prosper residents during a state of emergency. A tornado is one of the most violent storms that can rip through an area, striking quickly with little to no warning at all. Because the aftermath of a tornado can be devastating, preparing ahead of time is the best way to ensure you and your family’s safety. Please read the following questions about tornado safety, answered by Prosper Emergency Management Coordinator Kent Bauer. Q: During s evere weather, what does the Prosper Fire Department do? A: We monitor the weather alerts sent out by the National Weather Service. Because we are not meteorologists, we do not interpret any sort of storms or any sort of warnings. Instead, we pass along the information we receive from the National Weather Service to our residents through social media, storm sirens and Smart911 Rave weather warnings. Q: What does a Tornado Watch mean? A: Tornadoes are possible. Remain alert for approaching storms. Watch the sky and stay tuned to NOAA Weather Radio, commercial radio or television for information. Q: What does a Tornado Warning mean? A: A tornado has been sighted or indicated by weather radar and you need to take shelter immediately. Q: What is the reason for setting off the Outdoor Storm Sirens? A: To alert those who are outdoors that there is a tornado or another major storm event headed Prosper’s way, so seek shelter immediately. I f you are outside and you hear the sirens go off, do not call 9-1-1 to ask questions about the warning. -
Twisters in Two Cities: Stuctural Ritualization
TWISTERS IN TWO CITIES: STUCTURAL RITUALIZATION THEORY AND DISASTERS By KEVIN M. JOHNSON Bachelor of Arts in Psychology Northeastern State University Tahlequah, Oklahoma 2011 Master of Science in Sociology Oklahoma State University Stillwater, Oklahoma 2013 Submitted to the Faculty of the Graduate College of the Oklahoma State University in partial fulfillment of the requirements for the Degree of DOCTOR OF PHILOSOPHY May, 2019 TWISTERS IN TWO CITIES: STRUCTURAL RITUALIZATION THEORY AND DISASTERS Dissertation Approved: Dr. Duane A. Gill Dissertation Adviser Dr. J. David Knottnerus Dr. Monica Whitham Dr. Alex Greer ii ACKNOWLEDGEMENTS I would first like to thank my committee members – Dr. Duane Gill, Dr. J. David Knottnerus, Dr. Monica Whitham, and Dr. Alex Greer – for their insight and support throughout the writing of this dissertation. I am particularly grateful for Dr. Gill and Dr. Knottnerus, who have invested tremendous time and energy in mentoring and helping me develop as a sociologist and a thinker. I have had the privilege of working with some of my academic heroes on this project, and feel very fortunate to be able to make that claim. I would also like to thank my fellow graduate colleagues, Dr. Dakota Raynes, Christine Thomas, and many others, who were always willing to discuss various issues related to this research and countless other topics when needed. Your contributions to this work extend beyond the words on the page – thank you! Finally, I would like to acknowledge my family for their unwavering support and confidence in me throughout this process. Kasey, Gabriel, Ewok, and Leia: you have been my foundation, particularly in the toughest times, and I hope you all feel the joy of this accomplishment because it could not have happened without you. -
Samantha Santeiu 02-15-09 Sec. 9, Dave Defina Chasing a Storm
Samantha Santeiu 02-15-09 Sec. 9, Dave DeFina Chasing a Storm Specific Purpose Statement : To inform my audience how meteorologists chase storms and about the importance of storm chasing in meteorological research. Central Idea : Storm chasing requires special tools and software; chases follow a general procedure on the chase day; and chasing has great importance in meteorological research. Pattern of Organization : topical. INTRODUCTION It’s September, 1900, in Galveston, Texas. Isaac Cline, a well-known climatologist, rides his horse and buggy along the beach. He’s here to observe the unusually high, gusting winds and huge waves crashing onshore. He orders the people of Galveston to evacuate. [VISUAL AID] Little did he know, he had just chased the massive Galveston hurricane of 1900 that would proceed to kill at least 6,000 people in the area. According to “A Brief History of Storm Chasing” on the National Association of Storm Chasers and Spotters website, this is one of the first accounts of storm chasing that we have. How about this: how many of you have seen the movie Twister ? [VISUAL AID] The basic storyline is that two people are storm chasers, and in the end they chase an epically huge tornado in the name of research. That is a more modern, albeit a bit inaccurate, account of storm chasing. I would like to inform you today about chasing storms, the way meteorologists do it. I plan to research severe storms as a career, so I have investigated the topic thoroughly and interviewed peers and professors on the subject. While storm chasing may seem like fun, there’s actually a lot involved. -
Riding the Storm
physicsworld.com Careers Riding the storm out A career in severe-weather research offers flexibility and plenty of opportunities to experience the fascinating physics of the rotating fluid called the atmosphere. Josh Wurman describes the science of storm-chasing and why hurricanes are scarier than tornadoes Take me to the weather Josh Wurman enjoys the freedom that being a freelance meteorologist affords him. I am standing on a bridge near the North thematical, essentially applied fluid dynam- mapped out the winds inside tornadoes, so Carolina coast. There is a light breeze, and I ics, and the real-world effects of these equa- no-one really knew how strong they were. am enjoying some hazy sunshine. But this tions can be seen every day. The equations After reading the relevant literature, I de- calm is an illusion: in a few minutes winds of of motion for the atmosphere cause trees to cided that a more ambitious technological up to 45 m s–1 (100 mph) will sweep in again. be blown down, hail to fall and snowdrifts and logistical approach could push back the The approaches to my section of the bridge to pile up – all things that I could witness veil of ignorance about these fascinating phe- are already drowned under 2.5 m of water, while growing up in Pennsylvania. nomena. So in 1994 I decided to shift focus, and my companions on this island are an I started out as a physics major at the Mas- leaving NCAR for a faculty position at the eclectic mix of traumatized animals, inclu- sachusetts Institute of Technology (MIT), University of Oklahoma, where I developed ding snakes, rats, wounded pelicans and but my real interest was meteorology, in a prototype mobile weather radar system frogs. -
Impacts of Global Warming on Hurricane-Related Flooding in Corpus Christi,Texas
Impacts of Global Warming on Hurricane-related Flooding in Corpus Christi, Texas Sea-level Rise and Flood Elevation A one-foot rise in flood elevation due to both sea-level rise and hurricane intensification leads to an inundation of 5000 –15,000 feet. Global Sea-level Rise Global warming causes sea level to rise through Limitations of the Analysis two major mechanisms. First, as water warms, it expands, taking up more space. Second, as ice This analysis looked only at damages due to flooding by storm on land melts (including mountain glaciers surge and sea-level rise. It is not a comprehensive analysis of the wide array of hurricane-related damages. Other simplifying around the world as well as the polar ice assumptions were made and there were limitations due to lack of sheets), this water flows to the oceans. data. For example, no data on historical flood damage to oil The thermal expansion of the oceans and the refineries was available to the researchers. melting of mountain glaciers are well understood. Increased melting and loss of ice on In addition, the study assumes that the barrier island retains its elevation and volume as sea level rises, though under high rates of parts of the polar ice sheets has recently been sea-level rise, the relative condition of the barrier island would be observed, especially on Greenland, although how expected to weaken, posing additional risk for erosion of the island much and how fast the ice sheets will increase and for flooding in the bay, both of which would increase economic sea-level rise is not well known, and this damages. -
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 .............................................................................................. -
Template for Electronic Journal of Severe Storms Meteorology
Lyza, A. W., A. W. Clayton, K. R. Knupp, E. Lenning, M. T. Friedlein, R. Castro, and E. S. Bentley, 2017: Analysis of mesovortex characteristics, behavior, and interactions during the second 30 June‒1 July 2014 midwestern derecho event. Electronic J. Severe Storms Meteor., 12 (2), 1–33. Analysis of Mesovortex Characteristics, Behavior, and Interactions during the Second 30 June‒1 July 2014 Midwestern Derecho Event ANTHONY W. LYZA, ADAM W. CLAYTON, AND KEVIN R. KNUPP Department of Atmospheric Science, Severe Weather Institute—Radar and Lightning Laboratories University of Alabama in Huntsville, Huntsville, Alabama ERIC LENNING, MATTHEW T. FRIEDLEIN, AND RICHARD CASTRO NOAA/National Weather Service, Romeoville, Illinois EVAN S. BENTLEY NOAA/National Weather Service, Portland, Oregon (Submitted 19 February 2017; in final form 25 August 2017) ABSTRACT A pair of intense, derecho-producing quasi-linear convective systems (QLCSs) impacted northern Illinois and northern Indiana during the evening hours of 30 June through the predawn hours of 1 July 2014. The second QLCS trailed the first one by only 250 km and approximately 3 h, yet produced 29 confirmed tornadoes and numerous areas of nontornadic wind damage estimated to be caused by 30‒40 m s‒1 flow. Much of the damage from the second QLCS was associated with a series of 38 mesovortices, with up to 15 mesovortices ongoing simultaneously. Many complex behaviors were documented in the mesovortices, including: a binary (Fujiwhara) interaction, the splitting of a large mesovortex in two followed by prolific tornado production, cyclic mesovortexgenesis in the remains of a large mesovortex, and a satellite interaction of three small mesovortices around a larger parent mesovortex. -
Multiple-Platform and Multiple-Doppler Radar Observations of a Supercell Thunderstorm in South America During RELAMPAGO
AUGUST 2020 T R A P P E T A L . 3225 Multiple-Platform and Multiple-Doppler Radar Observations of a Supercell Thunderstorm in South America during RELAMPAGO a b c d ROBERT J. TRAPP, KAREN A. KOSIBA, JAMES N. MARQUIS, MATTHEW R. KUMJIAN, a b e a STEPHEN W. NESBITT, JOSHUA WURMAN, PAOLA SALIO, MAXWELL A. GROVER, Downloaded from http://journals.ametsoc.org/mwr/article-pdf/148/8/3225/4980676/mwrd200125.pdf by UNIVERSITY OF ILLINOIS user on 15 July 2020 b a PAUL ROBINSON, AND DEANNA A. HENCE a Department of Atmospheric Sciences, University of Illinois at Urbana–Champaign, Urbana, Illinois b Center for Severe Weather Research, Boulder, Colorado c Pacific Northwest National Laboratory, Richland, Washington, and University of Colorado Boulder, Boulder, Colorado d Department of Meteorology and Atmospheric Science, The Pennsylvania State University, University Park, Pennsylvania e Centro de Investigaciones del Mar y la Atmósfera, CONICET-UBA, and Departamento de Ciencias de la Atmósfera y los Océanos, UBA, UMI-IFAECI, CNRS-CONICET-UBA, Buenos Aires, Argentina (Manuscript received 20 April 2020, in final form 18 May 2020) ABSTRACT On 10 November 2018, during the RELAMPAGO field campaign in Argentina, South America, a thun- derstorm with supercell characteristics was observed by an array of mobile observing instruments, including three Doppler on Wheels radars. In contrast to the archetypal supercell described in the Glossary of Meteorology, the updraft rotation in this storm was rather short lived (;25 min), causing some initial doubt as to whether this indeed was a supercell. However, retrieved 3D winds from dual-Doppler radar scans were used to document a high spatial correspondence between midlevel vertical velocity and vertical vorticity in this storm, thus providing evidence to support the supercell categorization.