Starting in the mid-1900s, mobile radar vehicles were being used for academic and military research. In the late 1900s, mobile doppler weather radars were designed and created with the goal to study atmospheric phenomena. [1]
Starting in the mid-1900s, mobile radar vehicles were being used for academic and military research. In the late 1900s, mobile doppler weather radars were designed and created with the goal to study atmospheric phenomena. [1]
 | This section needs to be updated.(June 2024) |
Mobile doppler weather radars have been used on dozens of scientific and academic research projects from their invention in the late 1900s. [1] One problems facing meteorological researchers was the fact that mesonets and other ground-based observation methods were being deployed too slow in order to accurately measure and study high-impact atmospheric phenomena. [1] Between 1994-1995, the first Doppler on Wheels was constructed and was deployed for the first time at the end of the VORTEX1 Project. [1] The Doppler on Wheels led to several scientific breakthroughs and theories regarding tornadoes. [1] The Doppler on Wheels also led to the “first tornado wind maps, measurements of an axial downdraft and lofted debris, multiple vortices, winds versus damage and surface measurement intercomparisons, winds as low as 3–4 m (9.8–13.1 ft) above the ground level and low-level inflow, 3D ground-based velocity track display (GBVTD) vector wind field retrievals, rapid evolution of debris over varying land use and terrain, documentation of cyclonic/anticyclonic tornado pairs and documentation of varied and complex tornado wind field structures including multiple wind field maxima and multiple vortex mesocyclones, downward propagation of vorticity and an extensive climatology of tornado intensity and size revealing, quantitatively, that tornadoes are much more intense and larger than indicated by damage surveys.” [1]
In 2011, Howard Bluestein, a research professor at the University of Oklahoma, led a team to develop the Rapid X-band Polarimetric Radar (RaXPol). [2] [3] [4] In 2013, researchers published to the American Meteorological Society that RaXPol was created because “the need for rapidly scanning weather radars for observing fast-changing weather phenomena such as convective storms, microbursts, small-scale features in hurricanes, and the process of convective development has been well established” throughout history. [2] This included publications by the National Center for Atmospheric Research in 1983, [5] research by several scientists published in 2001, [6] and published research by the U.S. federal government in 2012. [7] The United States Department of Defense gave the University of Oklahoma over $5 million dollars (2019 USD) in the development of new mobile radars, which were set to be used by the United States Navy. [8]
In 2023, the University of Oklahoma, along with the National Severe Storms Laboratory developed and deployed the first ever mobile phased array radar (HORUS). [9] [10]
Several tornadoes throughout the last few decades have been observed by various mobile radars. However, only the most notable ones are used for academic research and subsequently published. [11] This is a list of known tornadoes which were observed by mobile radars.
| Official rating | Date | Location | Minimum peak wind speed | Maximum peak wind speed | Highest confirmed peak wind speed |
|---|---|---|---|---|---|
| F4 | April 26, 1991 | Ceres, Oklahoma | 268 mph (431 km/h) | 280 mph (450 km/h) | 280 mph (450 km/h) |
| A University of Oklahoma chase team headed by Howard Bluestein utilized mobile doppler weather radar to analyze the tornado. The radar measured peak winds of 120–125 m/s (270–280 mph; 430–450 km/h) between 150–190 m (490–620 ft) above the surface. [11] At the time, this represented the strongest winds ever measured by radar, including the first measurements of F5 intensity winds. [12] [13] | |||||
| F4 | May 30, 1998 | Spencer, South Dakota | 234 mph (377 km/h) | 266 mph (428 km/h) | 264 mph (425 km/h) |
| A Doppler on Wheels recorded winds of 264 mph (425 km/h) "well below" 50 metres (160 ft) above the ground level, "perhaps as low as 5–10 metres (16–33 ft) above the radar level". [14] [11] The Doppler on Wheels also recorded a confirmed five-second wind speed average of 112 m/s (250 mph; 400 km/h). [14] | |||||
| F4 | May 3, 1999 | Mulhall, Oklahoma | 246 mph (396 km/h) | 299 mph (481 km/h) | 257 mph (414 km/h) |
| A Doppler on Wheels documented the largest-ever-observed core flow circulation with a distance of 1,600 m (5,200 ft) between peak velocities on either side of the tornado, and a roughly 7 km (4.3 mi) width of peak wind gusts exceeding 43 m/s (96 mph), making the Mulhall tornado the largest tornado ever measured quantitatively. [15] The DOW measured a complex multi-vortex structure, [16] with several vortices containing winds of up to 115 m/s (260 mph) rotating around the tornado. The 3D structure of the tornado has been analyzed in a 2005 article in the Journal of the Atmospheric Sciences by Wen-Chau Lee and Joshua Wurman. [17] In 2024, it was published that the radar did measure winds of approximately 257 mph (414 km/h) approximately 30 m (98 ft) above the radar level. [11] | |||||
| F5 | May 3, 1999 | Bridge Creek, Oklahoma | 281 mph (452 km/h) | 321 mph (517 km/h) | 321 mph (517 km/h) |
| In 2007, Joshua Wurman along with other researchers, published that a Doppler on Wheels recorded 135 m/s (300 mph; 490 km/h) approximately 32 metres (105 ft) above the radar level. [18] [11] In 2021, Wurman along with other researchers, revised the data using improved techniques and published that the Doppler on Wheels actually recorded 321 miles per hour (517 km/h) in the tornado. [1] [19] | |||||
| F0 | April 30, 2000 | Crowell, Texas | — | — | — |
| A Doppler on Wheels observed this tornado. This was the first of three tornadoes observed by the Doppler on Wheels near Crowell, Texas on April 30, 2000. [20] | |||||
| F0 | April 30, 2000 | Crowell, Texas | — | — | — |
| A Doppler on Wheels observed this tornado. This was the second of three tornadoes observed by the Doppler on Wheels near Crowell, Texas on April 30, 2000. [21] | |||||
| F0 | April 30, 2000 | Crowell, Texas | — | — | — |
| A Doppler on Wheels observed this tornado. This was the third of three tornadoes observed by the Doppler on Wheels near Crowell, Texas on April 30, 2000. [22] | |||||
| F1 | April 30, 2000 | Oklaunion, Texas | — | — | — |
| A Doppler on Wheels observed this F1 tornado. [23] | |||||
| F2 | May 29, 2004 | Geary, Oklahoma | — | — | 181 mph (291 km/h) |
| A Doppler on Wheels recorded a peak wind gust of 81 m/s (180 mph; 290 km/h) at 6.5 m (21 ft) above the ground level. [24] | |||||
| F1 | May 29, 2004 | Calumet, Oklahoma | — | — | — |
| A Doppler on Wheels observed an anticyclonic F1 tornado near Calumet, Oklahoma. [25] | |||||
| F1 | May 13, 2005 | Truscott, Texas | — | — | 110 mph (180 km/h) |
| A Doppler on Wheels observed the tornado and recorded a peak wind speed of 110 mph (180 km/h). [26] | |||||
| F3 | May 13, 2005 | Vera, Texas | — | — | 177 mph (285 km/h) |
| A Doppler on Wheels recorded a peak wind speed of 177 mph (285 km/h) about 30 m (98 ft) above the ground level. [27] | |||||
| F0 | May 13, 2005 | Bomarton, Texas | — | — | 51 mph (82 km/h) |
| A Doppler on Wheels recorded a peak wind speed of 51 mph (82 km/h) about 20 m (66 ft) above the ground level. [28] | |||||
| F2 | June 12, 2005 | Clairemont, Texas | 100 mph (160 km/h) | 201 mph (323 km/h) | 201 mph (323 km/h) |
| A Doppler on Wheels observed the tornado through its entire life. The radar recorded winds of 100 mph (160 km/h), 145 mph (233 km/h), and 201 mph (323 km/h) at various heights ranging from 3–50 m (9.8–164.0 ft). [29] | |||||
| F0 | June 15, 2005 | Trego Center, Kansas | — | — | — |
| A Doppler on Wheels observed the tornado in an open field. [30] | |||||
| EF5 | May 4, 2007 | Greensburg, Kansas | — | — | — |
| An X-band mobile radar owned by the University of Massachusetts (UMass X-Pol) observed the tornado. [31] | |||||
| EF2 | June 5, 2009 | Goshen County, Wyoming | — | — | 271 mph (436 km/h) |
| A Doppler on Wheels observed the entire lifecycle of an EF2 tornado in Goshen County, Wyoming. The radar also observed a peak wind speed of 271 mph (436 km/h) at 15–20 m (49–66 ft) above the ground level. [32] | |||||
| EF5 | May 24, 2011 | Hinton, Oklahoma | 289 mph (465 km/h) | 296 mph (476 km/h) | 295.5 mph (475.6 km/h) |
| RaXPol recorded a wind gust of 124.8 m/s (279 mph; 449 km/h) about 200–230 feet (60–70 m) above the radar level. [33] However, this data was later revised to be 132.1 m/s (295 mph; 476 km/h) at 72 ft (22 m) above the radar level. [34] [11] | |||||
| EF4 | May 18, 2013 | Rozel, Kansas | 165 mph (266 km/h) | 185 mph (298 km/h) | 185 mph (298 km/h) |
| A Doppler on Wheels recorded "near surface" winds of between 165–185 mph (266–298 km/h). [35] | |||||
| EF2 | May 19, 2013 | Clearwater, Kansas | — | — | 155 mph (249 km/h) |
| A Doppler on Wheels recorded winds of 155 mph (249 km/h) at 70 m (230 ft) above the ground level. [36] | |||||
| EF3 | May 28, 2013 | Bennington, Kansas | — | — | 264 mph (425 km/h) |
| A Doppler on Wheels recorded winds of 264 mph (425 km/h) approximately 153 ft (47 m) above the ground level. [37] | |||||
| EF3 | May 31, 2013 | El Reno, Oklahoma | 291 mph (468 km/h) | 336 mph (541 km/h) | 313 mph (504 km/h) |
| A Doppler on Wheels recorded winds between 257–336 mph (414–541 km/h) at or less than 100 metres (330 ft) above the radar level in a suction vortex inside the tornado. [11] This was later revised by the Doppler on Wheels team to 291–336 mph (468–541 km/h). [19] In 2015, Howard Bluestein, along with other researchers, reported that the radar did capture at least a moment of winds of 313 miles per hour (504 km/h). [38] | |||||
| EF3 | May 9, 2016 | Sulphur, Oklahoma | — | — | 218 mph (351 km/h) |
| A Doppler on Wheels operated by the Center for Severe Weather Research recorded winds of 218 mph (351 km/h) at 17 m (56 ft) above the radar level. [39] | |||||
| EF2 | May 24, 2016 | Dodge City, Kansas | — | — | 201 mph (323 km/h) |
| While a Doppler on Wheels was observing the tornado, it documented winds of 40 m/s (89 mph; 140 km/h), which increased to at least 90 m/s (200 mph; 320 km/h) over a span of 21 seconds. These winds lasted less than one minute. [40] | |||||
| EF2 | May 20, 2019 | Mangum, Oklahoma | — | — | 122.7 mph (197.5 km/h) |
| The University of Oklahoma's RaXPol observed this tornado and recorded a maximum VROT of 106.6 kn (122.7 mph; 197.4 km/h). [41] [42] | |||||
| EF4 | March 24, 2023 | Rolling Fork, Mississippi | — | — | — |
| At least two mobile radars on the PERiLS Project observed the violent EF4 tornado at a height of 600–700 m (2,000–2,300 ft) above the radar level. [43] | |||||
| EF3 | April 26, 2024 | Harlan, Iowa | — | — | 224 mph (360 km/h) |
| A Doppler on Wheels recorded a wind gust of ~79 m/s (180 mph) about 258 m (846 ft) above the radar level. Peak ground level wind speed was estimated around 224 mph (360 km/h). [44] [45] [46] | |||||
| EF2 | April 27, 2024 | Dexter, Kansas | — | — | — |
| A Doppler on Wheels observed an EF2 tornado near Dexter, Kansas. [47] | |||||
| EF1 | April 27, 2024 | Dexter, Kansas | — | — | — |
| A Doppler on Wheels observed an EF1 tornado near Dexter, Kansas. [47] | |||||
| EF4 | May 21, 2024 | Greenfield, Iowa | 309 mph (497 km/h) | 318 mph (512 km/h) | ≥309 mph (497 km/h) |
| A Doppler on Wheels recorded winds of 263–271 mph (423–436 km/h) approximately 30–50 m (98–164 ft) above the radar level. Following calculations to more accurately determine peak wind speeds, it was published that ground-relative winds of 309–318 mph (497–512 km/h) could be observed briefly to the immediate east of the main circulation. [19] | |||||
| EF2 | May 22, 2024 | Temple, Texas | — | — | — |
| A Doppler on Wheels observed an EF2 tornado near Temple, Texas. [48] | |||||
| EF2 | May 23, 2024 | Duke, Oklahoma & Olustee, Oklahoma | — | — | 180 mph (290 km/h) |
| Two Doppler on Wheels scanned a large and long-lived EF2 tornado near Duke, Oklahoma. [49] [50] [51] [52] A mobile radar from Texas Tech University recorded winds of 180 mph (290 km/h) less than 20 m (22 yd) above the surface. [53] | |||||
| EFU | May 25, 2024 | Windthorst, Texas | — | — | — |
| The University of Oklahoma’s RaXPol observed and documented a tornado near Windthorst, Texas. [54] [55] | |||||
A tornado is a violently rotating column of air that is in contact with both the surface of the Earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. It is often referred to as a twister, whirlwind or cyclone, although the word cyclone is used in meteorology to name a weather system with a low-pressure area in the center around which, from an observer looking down toward the surface of the Earth, winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern. Tornadoes come in many shapes and sizes, and they are often visible in the form of a condensation funnel originating from the base of a cumulonimbus cloud, with a cloud of rotating debris and dust beneath it. Most tornadoes have wind speeds less than 180 kilometers per hour, are about 80 meters across, and travel several kilometers before dissipating. The most extreme tornadoes can attain wind speeds of more than 480 kilometers per hour (300 mph), are more than 3 kilometers (2 mi) in diameter, and stay on the ground for more than 100 km (62 mi).
From May 2 to 8, 1999, a large tornado outbreak took place across much of the Central and parts of the Eastern United States, as well as southern Canada. During this week-long event, 152 tornadoes touched down in these areas. The most dramatic events unfolded during the afternoon of May 3 through the early morning hours of May 4 when more than half of these storms occurred. Oklahoma experienced its largest tornado outbreak on record, with 70 confirmed. The most notable of these was the F5 Bridge Creek–Moore tornado which devastated Oklahoma City and suburban communities. The tornado killed 36 people and injured 583 others; losses amounted to $1 billion, making it the first billion-dollar tornado in history. Overall, 50 people lost their lives during the outbreak and damage amounted to $1.4 billion. For these reasons, the outbreak is known in Oklahoma as the May 3rd outbreak or the Oklahoma tornado outbreak of 1999.
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, holds records for longest path length at 219 miles (352 km) and longest duration at about 3+1⁄2 hours, and 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 second costliest tornado in history at the time, and when costs are normalized for wealth and inflation, it still ranks third today.
A hook echo is a pendant or hook-shaped weather radar signature as part of some supercell thunderstorms. It is found in the lower portions of a storm as air and precipitation flow into a mesocyclone, resulting in a curved feature of reflectivity. The echo is produced by rain, hail, or debris being wrapped around the supercell. It is one of the classic hallmarks of tornado-producing supercells. The National Weather Service may consider the presence of a hook echo coinciding with a tornado vortex signature as sufficient to justify issuing a tornado warning.
An anticyclonic tornado is a tornado which rotates in a clockwise direction in the Northern Hemisphere and a counterclockwise direction in the Southern Hemisphere. The term is a naming convention denoting the anomaly from normal rotation which is cyclonic in upwards of 98 percent of tornadoes. Many anticyclonic tornadoes are smaller and weaker than cyclonic tornadoes, forming from a different process, as either companion/satellite tornadoes or nonmesocyclonic tornadoes.
The radius of maximum wind (RMW) is the distance between the center of a cyclone and its band of strongest winds. It is a parameter in atmospheric dynamics and tropical cyclone forecasting. The highest rainfall rates occur near the RMW of tropical cyclones. The extent of a cyclone's storm surge and its maximum potential intensity can be determined using the RMW. As maximum sustained winds increase, the RMW decreases. Recently, RMW has been used in descriptions of tornadoes. When designing buildings to prevent against failure from atmospheric pressure change, RMW can be used in the calculations.
Doppler on Wheels is a fleet of X-band and C-band mobile and quickly-deployable truck-borne radars which are the core instrumentation of the Flexible Array of Radars and Mesonets affiliated with the University of Illinois and led by Joshua Wurman, with the funding partially provided by the National Science Foundation (NSF), as part of the "Community Instruments and Facilities," (CIF) program. The DOW fleet and its associated Mobile Mesonets and deployable weather stations have been used throughout the United States since 1995, as well as occasionally in Europe and Southern America. The Doppler on Wheels network has deployed itself through hazardous and challenging weather to gather data and information that may be missed by conventional stationary radar systems.
Joshua Michael Aaron Ryder Wurman is an American atmospheric scientist and inventor noted for tornado, tropical cyclone, and weather radar research, the invention of DOW and bistatic radar multiple-Doppler networks.
A satellite tornado is a tornado that revolves around a larger, primary tornado and interacts with the same mesocyclone. Satellite tornadoes occur apart from the primary tornado and are not considered subvortices; the primary tornado and satellite tornadoes are considered to be separate tornadoes. The cause of satellite tornadoes is not known. Such tornadoes are more often anticyclonic than are typical tornadoes and these pairs may be referred to as tornado couplets. Satellite tornadoes commonly occur in association with very powerful, large, and destructive tornadoes, indicative also of the strength and severity of the parent supercell thunderstorm.
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.
A prolonged and widespread tornado outbreak affected a large portion of the United States in late-May 2013 and early-June 2013. The outbreak was the result of a slow-moving but powerful storm system that produced several strong tornadoes across the Great Plains states, especially in Kansas and Oklahoma. Other strong tornadoes caused severe damage in Nebraska, Missouri, Illinois, and Michigan. The outbreak extended as far east as Upstate New York. 27 fatalities were reported in total, with nine resulting from tornadoes.
The 2013 El Reno tornado was an extremely large, powerful, and erratic tornado that occurred over rural areas of Central Oklahoma during the early evening of Friday, May 31, 2013. 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 in excess of 313 mph (504 km/h) 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 RapidX-bandPolarimetric Radar, commonly abbreviated as RaXPol, is a mobile research radar designed and operated by the University of Oklahoma, led by Howard Bluestein. RaXPol often collaborates with adjacent mobile radar projects, such as Doppler on Wheels and SMART-R. Unlike its counterparts, RaXPol typically places emphasis on temporal resolution, and as such is capable of surveilling the entire local atmosphere in three dimensions in as little as 20 seconds, or a single level in less than 3 seconds.
The 2011 El Reno–Piedmont tornado was a long-tracked and deadly EF5 tornado that struck central Oklahoma on the evening of May 24, 2011. The tornado impacted areas near or within the communities of El Reno, Piedmont, and Guthrie, killing nine and injuring 181. After producing incredible damage in several locations along a path of more than 60 miles (97 km), the El Reno–Piedmont tornado was given a rating of EF5, the highest category on the Enhanced Fujita scale. It was the first tornado rated EF5 or F5 to strike Oklahoma since the 1999 Bridge Creek–Moore tornado. A mobile radar found that the tornado possessed possible wind speeds of up to 295 mph (475 km/h).
A descending reflectivity core (DRC), sometimes referred to as a blob, is a meteorological phenomenon observed in supercell thunderstorms, characterized by a localized, small-scale area of enhanced radar reflectivity that descends from the echo overhang into the lower levels of the storm. Typically found on the right rear flank of supercells, DRCs are significant for their potential role in the development or intensification of low-level rotation within these storms. The descent of DRCs has been associated with the formation and evolution of hook echoes, a key radar signature of supercells, suggesting a complex interplay between these cores and storm dynamics.
This is a timeline of scientific and technological advancements as well as notable academic or government publications in the area of atmospheric sciences and meteorology during the 21st century. Some historical weather events are included that mark time periods where advancements were made, or even that sparked policy change.
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.
Winds of ~224 mph and diameter of max winds of ~2966 ft. Observations were taken as part of the @NSF -sponsored #BEST project led by @karen_kosiba and @JoshuaWurman
These data: Height ~258 m ARL (see 2) Gate 12m/beam 122m, gusts ~1sec