The history of tornado research spans back centuries, with the earliest documented tornado occurring in 200 and academic studies on them starting in the 18th century. This is a timeline of government or academic research into tornadoes.
Pre-18th century
The earliest-known tornado occurred in Sardegna, Sardinia and Corsica, Roman Empire (modern-day Italy) in 200.[1]
The earliest-known German tornado struck Freising (modern day Germany) in 788.[2][3] The earliest-known Irish tornado appeared on April 30, 1054, in Rostella, near Kilbeggan. The earliest-known British tornado hit central London on October 23, 1091, and was especially destructive, with modern research classifying it as an F4 on the Fujita scale.[4]
After the discovery of the New World, tornadoes documentation expanded into the Americas. On August 21, 1521, an apparent tornado is recorded to have struck Tlatelolco (present day Mexico City), just two days before the Aztec capital's fall to Cortés. Many other tornadoes are documented historically within the Basin of Mexico.[5] The first confirmed tornado in the United States struck Rehoboth, Massachusetts in August 1671.[6][7][8] The first confirmed tornadic death in the United States occurred on July 8, 1680 after a tornado struck Cambridge, Massachusetts.[9]
18th century
The first case study on a tornado took place following the violent 1764 Woldegk tornado, which struck around Woldegk, Duchy of Mecklenburg-Strelitz, Holy Roman Empire (modern-day Germany).[10] Between 1764 and 1765, German scientist Gottlob Burchard Genzmer published a detailed survey of the damage path from the tornado. It covers the entire, 33 km (18.6 mi) long track and also includes eyewitness reports as well as an analysis of the debris and hail fallout areas. Genzmer calls the event an "Orcan" and only compares it to waterspouts or dust devils.[11][12] Based on the damage survey, modern day meteorologists from the ESSL were able to assign a rating of F5, on the Fujita scale, and T11 on the TORRO scale, making it the earliest known F5 tornado worldwide.[10] The T11 rating on the TORRO scale also places this event among the most violent tornadoes ever documented worldwide.[10]
19th century
In 1838, the earliest recorded Asian tornado struck near the city of Calcutta in present-day West Bengal, India. It was described as moving remarkably slow across its 16-mile (26 km) path southeast over the span of 2 to 3 hours. It was recorded to cause significant damage to the area, including 3.5-pound (1.6 kg) hail being observed at the Dum Dum weather observatory.[13]
Between 1839 and 1841, a detailed survey of damage path of significant tornado that struck New Brunswick, New Jersey on 19 June 1835, which was the deadliest tornado in New Jersey history, occurred. The path was surveyed by many scientists on account of its location between New York City and Philadelphia, including early tornado theorists James Pollard Espy and William Charles Redfield. Scientists disagreed whether there was whirling, convergent, or rotational motion. A conclusion that remains accurate today is that the most intense damage tends to be on right side of a tornado (with respect to direction of forward movement), which was found to be generally easterly).[14][15]
In 1840, the earliest known intensive study of a tornadic event published in Europe, by French scientist Athanase Peltier.[16]
In 1865, the first in India and earliest known scientific survey of a tornado that analyzed structure and dynamics was published in 1865 by Indian scientist Chunder Sikur Chatterjee. The path damage survey of a tornado that occurred at Pundooah (now Pandua), Hugli district, West Bengal, India, was documented on maps and revealed multiple vortices, the tornadocyclone, and direction of rotation,[17] predating work by John Park Finley, Alfred Wegener, Johannes Letzmann, and Ted Fujita.
20th century
1920s
On March 18, 1925, the violent Tri-State tornado occurred, killing 695 people, while traveling 219 miles (352 km) over a period of 3 hours and 45 minutes. At one point, the tornado was moving with a forward speed of 73 miles per hour (117 km/h), setting the record as the fastest forward moving violent tornado in history. The tornado also became the deadliest tornado in United States history as well as the longest traveled tornado in history. All of these records have led the Tri-State tornado to be extensively surveyed and analyzed by academic researchers.[18][19][20]
1940s
Between 1945 and 1946, Floyd C. Pate, a forecaster at the United States Weather Bureau office in Montgomery, Alabama undertook an extensive survey and assessment of the tornado outbreak of February 12, 1945 and the 1945 Montgomery–Chisholm tornado. Pate later would describe the Montgomery–Chisholm tornado as "the most officially observed one in history", as it passed 2 miles (3.2 km) away from four different government weather stations, including the U.S. Weather Bureau office in Montgomery.[21]
On April 21, 1946, a tornado struck the area in and around Timber Lake, South Dakota. The United States Weather Bureau published a paper later in the year stating the width of this tornado was 4 miles (6.4 km), which would make this the widest tornado ever documented in history.[22]
1950s
In September 1958, E.P. Segner Jr. published a case study on the 1957 Dallas tornado. In the analysis, Senger estimated that the tornado had winds at least up to 302 mph (486 km/h), due to the obliteration of a large billboard.[23] The 1957 Dallas tornado was also studied extensively by the Severe Weather Forecast Unit in Kansas City, who proved several prominent theories about tornadoes were wrong. One of these-then proven false theories was that all air and debris flowed inward into the funnel and then upward, but on the outside edges of the funnel debris and people were even lifted. Among the studies was the first-ever photogrammetric analysis of wind speeds in a tornado. The film of the tornado is still regarded as being of exceptionally high quality and sharpness. Additionally, structural surveys following this and the Fargo tornado later in the year provided data that contributed to the development of the Fujita scale.[24][6]
1960s
On June 25, 1967, the Royal Netherlands Meteorological Institute (KNMI) issued a weather forecasting calling for tornadoes, which became the first-ever tornado forecast in Europe.[25]
1970s
In 1971, Ted Fujita, with the University of Chicago, in collaboration with Allen Pearson, head of the National Severe Storms Forecast Center/NSSFC (currently the Storm Prediction Center/SPC), introduced the Fujita scale as a way to estimate a tornado's intensity. Following the scale's introduction, tornadoes across the United States were retroactively rated on the scale going back to 1950, and the National Oceanic and Atmospheric Administration (NOAA) formally adopted the scale. The scale was updated in 1973, taking into account path length and width, becoming the modern-day Fujita scale.[26] Ted Fujita rated tornadoes from 1916 to 1992, however, pre-1949 rating were not formally accepted by the U.S. government.[27][28]
Between April 3–4, 1974, a catastrophic Super Outbreak occurred across the United States, which produced 148 tornadoes in a 24-hour period and led to the deaths of 335 people.[29] The 1974 Super Outbreak was extensively studied by Ted Fujita along with other researchers.[30][31][32] Following the outbreak, Fujita and a team of colleagues from the University of Chicago, University of Oklahoma, and National Severe Storms Laboratory, undertook a 10-month study of the 1974 Super Outbreak. Along with discovering new knowledge about tornadoes, such as downbursts and microbursts, and assessing damage to surrounding structures, the violent tornado which struck Xenia, Ohio was determined to be the worst out of 148 storms.[33][34] Fujita initially assigned a preliminary rating of F6 intensity ± 1 on the Fujita scale,[35] before stating F6 ratings were "inconceivable".[36]
1990s
In 1993, Thomas P. Grazulis, head of The Tornado Project and regarded tornado expert, published Significant Tornadoes 1680–1991 in which, he documented all known significant tornadoes, which he considered F2–F5 intensity or one that caused a death, in the United States going back to 1680. He also retroactively rated significant tornadoes in the United States going back to 1880.[6] This book, also called the "de facto bible of U.S. tornado history" is widely cited by meteorologists, historians, and by the United States government.[37]
21st century
2000s
In 2002, a Service Assessment Team was formed by the United States government to assess the quality of forecasts and post-tornado assessments conducted by the National Weather Service (NWS) office in Baltimore/Washington for the 2002 La Plata tornado. Their assessment and findings, released in September 2002, found that the local NWS office failed to indicate the initial findings of F5 damage on the Fujita scale was "preliminary" to the media and public.[38] The Service Assessment Team also recommended the National Oceanic and Atmospheric Administration require local National Weather Service offices to only release "potentially greater than F3" if F4 or F5 damage was suspected and to only release information regarding F4 or F5 damage after Quick Response Team (QRT) had assessed the damage.[38] Following the report, the National Weather Service created a national Quick Response Team (QRT), whose job is to assess and analyze locations believed to have sustained F4 or F5 damage on the Fujita scale.[38]
In February 2007, the Enhanced Fujita scale is formally released and put into use across the United States, replacing the Fujita scale.[39][40] In May, the 2007 Greensburg tornado family occurred, producing a tornado family of 22 tornadoes, including the first tornado to receive the rating of EF5 on the Enhanced Fujita scale; the 2007 Greensburg tornado.[41]
In August 2008, Timothy P. Marshall, a meteorologist and structural and forensic engineer with Haag Engineering, Karl A. Jungbluth with the National Weather Service, and Abigail Baca with RMS Consulting Group, published a detailed damage survey and analysis for the 2008 Parkersburg–New Hartford tornado.[42] In October, Matthew R. Clark with the United Kingdom's Met Office published a case study on a tornadic storm in southern England on December 30, 2006.[43]
2010s
In April 2011, the Super Outbreak, the largest and costliest tornado outbreak ever to occur, produces 360 tornadoes across the Midwestern, Southern, and Northeastern United States, leading to dozens of academic studies.[44][45][46] On May 22, 2011, a violent EF5 tornado impacts Joplin, Missouri, killing 158 people, becoming the deadliest modern-day tornado in history.[47]
In April 2013, Environment Canada (EC) adopts a variation of the Enhanced Fujita scale (CEF-scale), replacing the Fujita scale across Canada.[48] In May, a violent EF5 tornado impacts Moore, Oklahoma, marking the last tornado to receive the rating of EF5 on the Enhanced Fujita scale.[49] A few days later, a violent tornado impacts areas around El Reno, Oklahoma.[50] The University of Oklahoma's RaXPol mobile Doppler weather radar, positioned at a nearby overpass, measured winds preliminarily analyzed as in excess of 296 mph (476 km/h). These winds are considered the second-highest ever measured worldwide, just shy of the 302 ± 22 mph (486 ± 35 km/h) recorded during the 1999 Bridge Creek–Moore tornado.[51][52] The El Reno tornado also had a documented width of 2.6 miles (4.2 km), which the modern-day National Weather Service stated was the widest tornado ever recorded, despite the United States government documenting and publishing about a tornado that was 4 miles (6.4 km) wide in 1946.[53][54]
In April 2014, meteorologist, structural and forensic engineer Timothy P. Marshall, along with the National Weather Service and Texas Tech University's National Wind Institute, published a detailed damage survey and analysis of the 2014 Mayflower–Vilonia, Arkansas EF4 tornado.[55] In October, researchers with the Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO), National Weather Service (NWS), National Severe Storms Laboratory (NSSL), and Timothy P. Marshall with Haag Engineering, published a detailed damage survey and analysis on the 2013 Moore, Oklahoma EF5 tornado.[56] During the same month, researchers at Lyndon State College and the University of Colorado Boulder published a damage and radar analysis of the 2013 Moore tornado.[57]
In 2015, the European Severe Storms Laboratory along with the Max Planck Institute for Nuclear Physics publish a detailed assessment of the 1764 Woldegk tornado, in which it was assigned a rating of F5 on the Fujita scale, marking the oldest official F5 tornado.[58]
In 2018, researchers with the University of Oklahoma's School of Meteorology (OU SoM), National Weather Service (NWS), National Severe Storms Laboratory (NSSL), and Ohio University, published a detailed analysis of the multiple-vortex nature of the 2013 El Reno, Oklahoma tornado.[59]
Between 2019 and 2023, the Targeted Observation by Radars and UAS of Supercells (TORUS) project, led by the University of Nebraska–Lincoln, along with the NOAA National Severe Storms Laboratory (NSSL), NOAA Office of Marine and Aviation Operations (OMAO), Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO), and Texas Tech University, and the University of Colorado Boulder, occurs.[60][61]
2020s
2020
In May 2020, researchers at Howard University, the Cooperative Science Center for Atmospheric Sciences and Meteorology, and the National Center for Atmospheric Research (NCAR), published a detailed damage survey and analysis on the 2011 Tuscaloosa–Birmingham EF4 tornado.[62]
2021
In 2021, Nate DeSpain, with the University of Louisville and Tom Reaugh, with the National Weather Service, published a detailed damage survey and analysis of the 1890 Louisville tornado, where it was rated F4 on the Fujita scale.[63]
2022
In March 2022, the National Weather Service published a new damage survey and analysis for the 2012 Henryville EF4 tornado, where a "possible EF5 damage" location is identified and discussed.[64] In July, a research team, from the University of Oklahoma, National Severe Storms Laboratory, and University of Alabama in Huntsville was funded by the National Oceanic and Atmospheric Administration to investigate a stretch 8.7 miles (14 km) of the 2019 Greenwood Springs, Mississippi EF2 tornado where the National Weather Service was unable to survey. In their survey, published in Monthly Weather Review, they note that the tornado "produced forest devastation and electrical infrastructure damage up to at least EF4 intensity" and conclude by writing that "the Greenwood Springs event was a violent tornado, potentially even EF5 intensity."[65]
In October, Shifu R. Careaga with the University of Kentucky published a case study on the 2021 Western Kentucky tornado, linking the tornado to gravity & magnetic anomalies along the New Madrid Fault Line at the time of the tornado.[66]
Days later, Timothy Marshall, a meteorologist, structural and forensic engineer; Zachary B. Wienhoff, with Haag Engineering Company; Christine L. Wielgos, a meteorologist at the National Weather Service of Paducah; and Brian E. Smith, a meteorologist at the National Weather Service of Omaha, publish a detailed damage survey and analysis of the 2021 Western Kentucky EF4 tornado. In their conclusion, the researchers state, “the tornado damage rating might have been higher had more wind resistant structures been encountered. Also, the fast forward speed of the tornado had little ‘dwell’ time of strong winds over a building and thus, the damage likely would have been more severe if the tornado were slower.”[67]
2023
In January 2023, the 2023 Pasadena–Deer Park tornado prompts the National Weather Service forecasting office in Houston to issue a rare tornado emergency, the first ever issued by the office.[68][69][70] In April, the TORNADO Act was introduced by U.S. Senator Roger Wicker as well as eight other senators from the 118th United States Congress.[71] In July, the International Fujita scale (IF-scale) is officially published.[72] In September, the National Weather Service offices in Jackson, Mississippi and Nashville, Tennessee, along with the National Severe Storms Laboratory (NSSL) and the University of Oklahoma's CIWRO publish a joint damage survey and analysis on the 2023 Rolling Fork–Silver City EF4 tornado, the 2023 Black Hawk–Winona EF3 tornado, and the 2023 New Wren–Amory EF3 tornado.[73] In November, american meteorologist and tornado expert Thomas P. Grazulis publish Significant Tornadoes 1974–2022, which includes the outbreak intensity score (OIS), a new way to classify and rank tornado outbreaks.[74][75] Between December 2023 – April 2024, the Detecting and Evaluating Low-level Tornado Attributes (DELTA) project, led by NOAA, along with the National Severe Storms Laboratory and several research universities occured.[76]
2024
In February 2024, researchers with the University of Tennessee and University of Missouri publish an academic study about how survivors from the 2011 Joplin tornado recover from "Tornado Brain", a new term for the PTSD of tornado survivors.[77] During the same month, researchers with Auburn University (AU), Florida International University (FIU), Pennsylvania State University (Penn State), Louisiana State University (LSU), University of South Alabama, University of Illinois Urbana-Champaign (UIUC), University of Kentucky, and CoreLogic, published an academic case study on how hurricane-resistant houses preformed during the 2022 Arabi–New Orleans EF3 tornado.[78]
In March 2024, Anthony W. Lyza, Matthew D. Flournoy, and A. Addison Alford, researchers with the National Severe Storms Laboratory, Storm Prediction Center, CIWRO, and the University of Oklahoma's School of Meteorology, published a paper where they state, ">20% of supercell tornadoes may be capable of producing EF4–EF5 damage" and that "the legacy F-scale wind speed ranges may ultimately provide a better estimate of peak tornado wind speeds at 10–15 m AGL for strong–violent tornadoes and a better damage-based intensity rating for all tornadoes". In their conclusion, the researchers also posed the question: “Does a 0–5 ranking scale make sense given the current state of understanding of the low-level tornado wind profile and engineering of structures?”[79]
In April 2024, the European Severe Storms Laboratory and the Czech Hydrometeorological Institute, along with seven other European organizations, publish a detailed damage survey and analysis on the 2021 South Moravia tornado using the International Fujita scale.[80] Also in April, Timothy A. Coleman, with the University of Alabama in Huntsville (UAH), Richard L. Thompson with the NOAA Storm Prediction Center, and Dr. Gregory S. Forbes, a retired meteorologist from The Weather Channel publish an article to the Journal of Applied Meteorology and Climatology stating, "it is apparent that the perceived shift in tornado activity from the traditional tornado alley in the Great Plains to the eastern U.S. is indeed real".[81] On April 26, a Doppler on Wheels (DOW) mobile radar truck measured 1-second wind speeds of approximately 224 mph (360 km/h) at a height of ~282 yards (258 m) as a tornado passed near Harlan, Iowa, causing widespread destruction.[82][83] On April 30, strong tornado near Hollister, Oklahoma passed close to a NEXRAD radar. The radar measured a tornado vortex signature with a gate-to-gate of 260 miles per hour (420 km/h) about 600 feet (200 yd; 180 m) above the surface.[84][85]