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|Alma mater|| Northern Illinois University (B.S., 1978)|
Texas Tech University (M.S., 1980, 1983)
|Known for||Tornado damage analysis, wind and hail engineering|
|Fields||Structural engineering and meteorology|
|Thesis||The Utilization of Load and Resistance Statistics in a Wind Speed Assessment (1983)|
Timothy Patrick Marshall (born October 17, 1956) is an American structural and forensic engineer as well as meteorologist, concentrating on damage analysis, particularly that from wind and other weather phenomena. He is also a pioneering storm chaser and was editor of Storm Track magazine.
Marshall was born to Charles and Catherine Marshall in Evergreen Park near Chicago, in 1956 and raised in Oak Lawn, then in Oak Brook. Oak Lawn was heavily damaged during the historic 1967 Oak Lawn tornado outbreak of April 21, 1967, when he was 10 years old. The F4 "Oak Lawn tornado" touched down about 4 mi (6.4 km) west of his home and killed 33 in town, including some of his classmates. This experience served to strengthen his interest in meteorology, and he focused his studies on tornadoes.
Marshall attended Northern Illinois University (NIU) in DeKalb, attaining a B.S. degree in geography with a concentration in meteorology in 1978. As an undergraduate student there, he and classmates surveyed some tornado damage paths of the 1974 Super Outbreak during an informal trip to the National Climatic Data Center (NCDC) to collect severe weather data. Later, he and fellow students visited the National Severe Storms Forecast Center (NSSFC) and obtained a large collection of materials the library was dumping, which formed the basis of his own library.
Marshall went to Texas for graduate school, seeing his first tornado a few hours after entering the state. In 1978, he began storm chasing in west Texas and Oklahoma. He participated in field research and damage surveys. In 1980, he earned a M.S. degree majoring in atmospheric sciences from Texas Tech University in Lubbock with the thesis Topographic Influences on Amarillo Radar Echo Climatology , then went on to earn an M.S. degree in civil engineering from the same university. At Texas Tech, he worked part-time at the Institute for Disaster Research where he began surveying tornado and hurricane damage. His first official tornado damage survey was in Grand Island, Nebraska, in 1980 and his first hurricane damage survey was Hurricane Allen in south Texas later that year. His thesis was titled The Utilization of Load and Resistance Statistics in a Wind Speed Assessment .
In 1983, Marshall was hired by the leading Texas firm Haag Engineering and eventually became Senior Engineer and Meteorologist. At Haag, he travels a great deal surveying storm damage across the United States. He has conducted more than 100 damage surveys of hailstorms, tornadoes, and hurricanes. Some of the famous tornadoes he surveyed include the F5s at Jarrell, Texas (1997), Bridge Creek, Oklahoma (1999), Greensburg, Kansas (2007), Alabama (2011), Joplin, Missouri (2011), and Moore, Oklahoma (2013). Some of the famous hurricanes he has surveyed include Alicia in Texas (1983), Hugo in South Carolina (1989), Andrew in Florida (1992), Opal in Florida (1995), Katrina in Mississippi (2005), and Ike in Texas (2008). He became a Professional Engineer in 1989.
Marshall still finds time to pursue his hobby storm chasing. During the past 30 years, he filmed more than 200 tornadoes and experienced 17 hurricanes. In 2004, he rode out Hurricane Ivan in Pensacola, Florida and, in 2005, he rode out Hurricane Katrina in Slidell, Louisiana. In 2008, he rode out Hurricane Ike in Galveston, Texas.
Marshall appeared on dozens of television programs including those on The Discovery Channel, The Learning Channel, National Geographic Channel, The History Channel, and The Weather Channel. He was a guest on The Oprah Winfrey Show twice and appeared multiple times on NOVA . He has also been a radio guest, such as on NPR,and has been featured in magazines such as National Geographic and Weatherwise , to the latter of which he has contributed some articles. He also has published tornado related articles in the Bulletin of the American Meteorological Society and Weather and Forecasting .
Marshall was selected by the National Oceanic and Atmospheric Administration (NOAA) to serve on their Quick Response Team (QRT) where he has surveyed tornado damage in Alabama and Georgia in 1994, Nashville, Tennessee in 1998, La Plata, Maryland in 2002, Parkersburg, Iowa in 2008, the 2011 Super Outbreak, the 2011 Joplin tornado, and the 2015 Dallas-Ft. Worth Metroplex tornadoes. He was on the development team of the Fujita Scale Enhancement Project which produced an Enhanced Fujita Scale to update the original Fujita scale of tornado intensity. He was also a major contributor to the committee to update the Saffir–Simpson scale.He has been a principal trainer in damage surveys for the National Weather Service (NWS) since the 1990s. Between 2006 and 2012, he was elected to serve on the Severe Local Storms committee for the American Meteorological Society. In 2009 and 2010, he was part of the government sponsored VORTEX2 experiment working on the Center of Severe Weather Research (CSWR) team with Joshua Wurman. In 2012 he continued working with CSWR on the ROTATE (Radar Observations of Tornadoes and Thunderstorms Project). His job was to deploy in-situ pods in the paths of tornadoes and perform mobile mesonet transects of storm environments.
During his early years in Texas, Marshall was married to Kay, who he met at a concert. She is a natural history museum exhibit designer and an ornithologist. She sometimes accompanies him on storm chases. He learned and taught guitar as a youth and enjoys mountain climbing, snorkeling, and scuba diving.
Marshall has authored and coauthored numerous scientific publications in the realms of meteorology and civil engineering. In addition to editing and writing for Storm Track (1986–2002) and writing various articles for Weatherwise , he wrote the following booklets:
Marshall also released the following DVDs through Storm Track: 1991 Kansas Tornadoes, 1995 Wedgefest, 1998 Octoberfest, 1999 Oklahoma Tornado Outbreak, 2000 Millennium Chases, 2002 Chase Highlights, 2003 Chase Highlights, 2004 Midwest Mayhem, 2005 Spin Summer, 2007 Tornado Chases, 2008 Tornado and Hurricane Chases, 2009 Inside VORTEX 2, 2010 Tornado Chases, and Tim Marshall's 25 Years of Tornado Chasing.
The Fujita scale, or Fujita–Pearson scale, is a scale for rating tornado intensity, based primarily on the damage tornadoes inflict on human-built structures and vegetation. The official Fujita scale category is determined by meteorologists and engineers after a ground or aerial damage survey, or both; and depending on the circumstances, ground-swirl patterns, weather radar data, witness testimonies, media reports and damage imagery, as well as photogrammetry or videogrammetry if motion picture recording is available. The Fujita scale was replaced with the Enhanced Fujita scale (EF-Scale) in the United States in February 2007. In April 2013, Canada adopted the EF-Scale over the Fujita scale along with 31 "Specific Damage Indicators" used by Environment Canada (EC) in their ratings.
Tetsuya Theodore Fujita was a Japanese-American meteorologist whose research primarily focused on severe weather. His research at the University of Chicago on severe thunderstorms, tornadoes, hurricanes, and typhoons revolutionized the knowledge of each. Although he is best known for creating the Fujita scale of tornado intensity and damage, he also discovered downbursts and microbursts, and was an instrumental figure in advancing modern understanding of many severe weather phenomena and how they affect people and communities, especially through his work exploring the relationship between wind speed and damage.
This article lists various tornado records. The most "extreme" tornado in recorded history was the Tri-State tornado, which spread through parts of Missouri, Illinois, and Indiana on March 18, 1925. It is considered an F5 on the Fujita Scale, even though tornadoes were not ranked on any scale at the time. It holds records for longest path length at 219 miles (352 km), longest duration at about 3½ hours, and it held the fastest forward speed for a significant tornado at 73 mph (117 km/h) anywhere on Earth until 2021. In addition, it is the deadliest single tornado in United States history with 695 fatalities. It was also the third most costly tornado in history at the time, but has been surpassed by several others non-normalized. When costs are normalized for wealth and inflation, it still ranks third today.
During the evening hours of March 28, 2000, a powerful F3 tornado struck Downtown Fort Worth, Texas, causing significant damage to numerous buildings and skyscrapers as well as two deaths. The tornado was part of a larger severe weather outbreak that caused widespread storms across Texas and Oklahoma in late-March, spurred primarily by the moist and unstable atmospheric environment over the South Central United States as a result of an eastward-moving upper-level low and shortwave trough. The tornado outbreak was well forecast by both computer forecast models and the National Weather Service, though the eventual focal point for the severe weather—North Texas—only came into focus on March 28 as the conditions favorable for tornadic development quickly took hold.
Storm Track was the first magazine for and about storm chasing. The magazine was in circulation between 1977 and 2002.
The TORRO tornado intensity scale is a scale measuring tornado intensity between T0 and T11. It was proposed by Terence Meaden of the Tornado and Storm Research Organisation (TORRO), a meteorological organisation in the United Kingdom, as an extension of the Beaufort scale.
The Enhanced Fujita scale rates tornado intensity based on the severity of the damage they cause. It is used in some countries, including the United States, Canada, China, and Mongolia.
Joshua Michael Aaron Ryder Wurman is an American atmospheric scientist and inventor noted for tornado, tropical cyclone, and weather radar research.
On May 24–25, 1957, a tornado outbreak primarily affected the Western High Plains, Central Great Plains, and Central Oklahoma/Texas Plains of the United States. 45 tornadoes touched down over the area, most of which took place across northern and western Texas, in addition to southern Oklahoma. Overall activity initiated over eastern New Mexico and spread northeastward as far as southwestern Wisconsin. The strongest tornado, which occurred in southern Oklahoma on May 24, was assigned a rating of F4 near Lawton. Anomalously, some tornadoes touched down during the early morning hours, rather than late afternoon or early evening, when daytime heating typically peaks.
On April 2–5, 1957, a deadly tornado outbreak sequence struck most of the Southern United States. The outbreak killed at least 21 people across three states and produced at least 73 tornadoes from Texas to Virginia. The outbreak was most notable due to a tornado that hit a densely populated area of the Dallas–Fort Worth metropolitan area, killing 10 people and injuring 200 or more. The tornado, highly visible for most of its path, was at the time the most observed and best-documented tornado in recorded history; hundreds of people photographed or filmed the F3 tornado as it moved just west of Downtown Dallas. The film of this tornado is still known for its unusually high quality and sharpness, considering the photography techniques and technology of the 1950s. Damage from the Dallas tornado reached as high as $4 million. Besides the famous Dallas tornado, other deadly tornadoes struck portions of Mississippi, Texas, and Oklahoma. Two F4 tornadoes struck southern Oklahoma on April 2, killing five people. Three other significant, F2-rated tornadoes that day killed two people in Texas and one more in Oklahoma. An F3 tornado struck rural Mississippi on April 4, killing one more person.
Tornadoes are more common in the United States than in any other country or state. The United States receives more than 1,200 tornadoes annually—four times the amount seen in Europe. Violent tornadoes—those rated EF4 or EF5 on the Enhanced Fujita Scale—occur more often in the United States than in any other country.
The Verification of the Origins of Rotation in Tornadoes Experiment are field experiments that study tornadoes. VORTEX1 was the first time scientists completely researched the entire evolution of a tornado with an array of instrumentation, enabling a greater understanding of the processes involved with tornadogenesis. A violent tornado near Union City, Oklahoma was documented in its entirety by chasers of the Tornado Intercept Project (TIP) in 1973. Their visual observations led to advancement in understanding of tornado structure and life cycles.
On June 18–19, 1972, Hurricane Agnes generated the third-deadliest tropical cyclone-related tornado outbreak in the United States since 1900, as well as the deadliest such tornado outbreak on record in Florida. The outbreak lasted about 38 hours and produced at least 19 confirmed tornadoes, though some studies suggested nearly a dozen more. Two of the tornadoes killed a total of seven people and were not classified as tornadoes by the National Weather Service until 2018. In Florida alone, the outbreak inflicted at least 135 injuries and destroyed 15 homes, while 119 homes received damage. Statewide, 217 trailers were destroyed and 196 trailers incurred damage. Additionally, six businesses were destroyed, while six others were damaged.
During the early evening of Friday, May 31, 2013, a very large and powerful tornado occurred over rural areas of Central Oklahoma. This rain-wrapped, multiple-vortex tornado was the widest tornado ever recorded and was part of a larger weather system that produced dozens of tornadoes over the preceding days. The tornado initially touched down at 6:03 p.m. Central Daylight Time (2303 UTC) about 8.3 miles (13.4 km) west-southwest of El Reno, rapidly growing in size and becoming more violent as it tracked through central portions of Canadian County. Remaining over mostly open terrain, the tornado did not impact many structures; however, measurements from mobile weather radars revealed extreme winds up to 135.0 m/s within the vortex. These are among the highest observed wind speeds on Earth, just slightly lower than the wind speeds of the 1999 Bridge Creek–Moore tornado. As it crossed U.S. 81, it had grown to a record-breaking width of 2.6 miles (4.2 km), beating the previous width record set in 2004. Turning northeastward, the tornado soon weakened. Upon crossing Interstate 40, the tornado dissipated around 6:43 p.m. CDT (2343 UTC), after tracking for 16.2 miles (26.1 km), it avoided affecting the more densely populated areas near and within the Oklahoma City metropolitan area.
The following is a glossary of tornado terms. It includes scientific as well as selected informal terminology.
James M. Leonard, also known as "Cyclone Jim", was an American professional storm chaser, photographer, and videographer. Intercepting severe weather including thunderstorms, tornadoes, hurricanes and typhoons, he was among the earliest storm chasers. He was the first to photograph an anticyclonic tornado.
Hurricane Isbell spawned one of the most significant tornado outbreaks to strike the Miami metropolitan area on October 14, 1964. It produced at least nine confirmed, and possibly as many as 17, tornadoes, four of which were rated significant (F2) on the Fujita scale. Although there were no fatalities, 48 people were injured and losses totaled $560,250. The most damaging of the tornadoes was an estimated F2 that injured 22 people at a mobile home park in Briny Breezes, causing $250,000 in losses.
The International Fujita scale rates the intensity of tornadoes and other wind events based on the severity of the damage they cause. It is used by the European Severe Storms Laboratory (ESSL) and is being worked on by various other organizations including Deutscher Wetterdienst (DWD) and State Meteorological Agency (AEMET). The scale is intended to be analogous to the Fujita and Enhanced Fujita scales, while being more applicable internationally by accounting for factors such as differences in building codes.