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).
Twister is a 1996 American disaster thriller film directed by Jan de Bont from a screenplay by Michael Crichton and Anne-Marie Martin. It was produced by Crichton, Kathleen Kennedy, and Ian Bryce, with Steven Spielberg, Walter Parkes, Laurie MacDonald, and Gerald R. Molen serving as executive producers. The film stars an ensemble cast that includes Helen Hunt, Bill Paxton, Jami Gertz and Cary Elwes as a group of amateur but spirited storm chasers trying to deploy a tornado research device during a severe outbreak in Oklahoma. Twister was released in theaters on May 10, 1996. It is notable for being among the first films to be released on DVD in the United States.
On Tuesday, April 10, 1979, a widespread and destructive outbreak of severe weather impacted areas near the Red River between Oklahoma and Texas. Thunderstorms developed over West and North Central Texas during the day within highly unstable atmospheric conditions following the northward surge of warm and moist air into the region, producing large hail, strong winds, and multiple tornadoes. At least 22 tornadoes were documented on April 10, of which two were assigned an F4 rating on the Fujita scale; four of the tornadoes caused fatalities.
This is a list of meteorology topics. The terms relate to meteorology, the interdisciplinary scientific study of the atmosphere that focuses on weather processes and forecasting.
The National Severe Storms Laboratory (NSSL) is a National Oceanic and Atmospheric Administration (NOAA) weather research laboratory under the Office of Oceanic and Atmospheric Research. It is one of seven NOAA Research Laboratories (RLs).
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.
This page documents notable tornadoes and tornado outbreaks worldwide in 2008. Strong and destructive tornadoes form most frequently in the United States, Bangladesh, and Eastern India, but they can occur almost anywhere under the right conditions. Tornadoes also develop occasionally in southern Canada during the Northern Hemisphere's summer and somewhat regularly at other times of the year across Europe, Asia, and Australia. Tornadic events are often accompanied with other forms of severe weather, including strong thunderstorms, strong winds, and hail.
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.
From May 3 to May 11, 2003, a prolonged and destructive series of tornado outbreaks affected much of the Great Plains and Eastern United States. Most of the severe activity was concentrated between May 4 and May 10, which saw more tornadoes than any other week-long span in recorded history; 335 tornadoes occurred during this period, concentrated in the Ozarks and central Mississippi River Valley. Additional tornadoes were produced by the same storm systems from May 3 to May 11, producing 363 tornadoes overall, of which 62 were significant. Six of the tornadoes were rated F4, and of these four occurred on May 4, the most prolific day of the tornado outbreak sequence; these were the outbreak's strongest tornadoes. Damage caused by the severe weather and associated flooding amounted to US$4.1 billion, making it the costliest U.S. tornado outbreak of the 2000s. A total of 50 deaths and 713 injuries were caused by the severe weather, with a majority caused by tornadoes; the deadliest tornado was an F4 that struck Madison and Henderson counties in Tennessee, killing 11. In 2023, tornado expert Thomas P. Grazulis created the outbreak intensity score (OIS) as a way to rank various tornado outbreaks. The tornado outbreak sequence of May 2003 received an OIS of 232, making it the fourth worst tornado outbreak in recorded history.
TWISTEX was a tornado research experiment that was founded and led by Tim Samaras of Bennett, Colorado, US, that ended in the deaths of three researchers in the 2013 El Reno tornado. The experiment announced in 2015 that there were some plans for future operations, but no additional information has been announced since.
Howard Bruce Bluestein is a research meteorologist known for his mesoscale meteorology, severe weather, and radar research. He is a major participant in the VORTEX projects. A native of the Boston area, Dr. Bluestein received his Ph.D. in 1976 from MIT. He has been a professor of meteorology at the University of Oklahoma (OU) since 1976.
This page documents the tornadoes and tornado outbreaks of 1985, primarily in the United States. Most tornadoes form in the U.S., although some events may take place internationally. Tornado statistics for older years like this often appear significantly lower than modern years due to fewer reports or confirmed tornadoes.
Timothy Michael Samaras was an American engineer and storm chaser best known for his field research on tornadoes and time on the Discovery Channel show Storm Chasers. He died in the 2013 El Reno tornado.
National Weather Service - Norman, Oklahoma is a Weather Forecast Office (WFO) of the National Weather Service based in Norman, Oklahoma, which is responsible for forecasts and the dissemination of weather warnings and advisories for central and most of western Oklahoma, and western portions of north Texas. It is located in the National Weather Center on the University of Oklahoma campus, where it acts as one of the NOAA Weather Partners, a group of close-together weather-related agencies of the National Oceanic and Atmospheric Administration. NWS Norman is currently overseen by Mark Fox, who serves as the Meteorologist In Charge of the office.
Erik Nels Rasmussen is an American meteorologist and leading expert on mesoscale meteorology, severe convective storms, forecasting of storms, and tornadogenesis. He was the field coordinator of the first of the VORTEX projects in 1994-1995 and a lead principal investigator for VORTEX2 from 2009-2010 and VORTEX-SE from 2016-2017, as well as involved in other smaller VORTEX offshoots and many field projects.
The following is a glossary of tornado terms. It includes scientific as well as selected informal terminology.
Louis John Wicker is an American atmospheric scientist with expertise in numerical analysis, numerical simulation, and forecasts of severe convection and tornadoes. Doing storm chasing field research, Wicker deployed the TOtable Tornado Observatory (TOTO) and was in leadership roles in the VORTEX projects. He is also known for pioneering work simulating convection at the National Center for Supercomputing Applications (NCSA) at the University of Illinois at Urbana–Champaign (UIUC).
Roger Edwards is an American meteorologist and expert on severe convective storms (thunderstorms). He is the co-founder and editor-in-chief of the Electronic Journal of Severe Storms Meteorology (EJSSM).
This is a list of notable tornadoes and tornado outbreaks worldwide in 2023. Strong, destructive tornadoes form most frequently in the United States, Argentina, Brazil, Bangladesh and East India, but can occur almost anywhere. Tornadoes develop occasionally in southern Canada during the Northern Hemisphere's summer, and at other times of the year across Europe, Asia, Argentina, Australia and New Zealand. They are often accompanied by other forms of severe weather, including thunderstorms, strong winds, and large hail. Worldwide, 116 tornado-related deaths were confirmed – 83 in the United States, 12 in China, nine in Indonesia, eight in Myanmar, three in Turkey, and one in Saudi Arabia.
