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 km/h (110 mph), are about 80 m across, and travel several kilometers before dissipating. The most extreme tornadoes can attain wind speeds of more than 480 km/h (300 mph), are more than 3 km in diameter, and stay on the ground for more than 100 km.
Twister is a 1996 American epic disaster 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, Cary Elwes, Philip Seymour Hoffman, Alan Ruck, Todd Field, and Jeremy Davies as a group of amateur but spirited storm chasers trying to deploy a tornado research device during a severe outbreak in Oklahoma. Twister was officially released in theaters on May 10, 1996. It is notable for being the first film to be released on DVD in the United States.
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).
Thomas P. Grazulis is an American meteorologist who has written extensively about tornadoes and is head of The Tornado Project.
Doppler on Wheels is a fleet of X-band and C-band radar trucks managed by the University of Illinois Urbana-Champaign and previously maintained by the Center for Severe Weather Research (CSWR) in Boulder, Colorado, led by principal investigator (PI) Joshua Wurman, with the funding largely provided by the National Science Foundation (NSF). The DOW fleet and its associated Mobile Mesonets and deployable weather stations (Pods) were Lower Atmospheric Observing Facilities (LAOF) "National Facilities" supporting a wide variety NSF-sponsored research. They are now included in the NSF's "Community Instruments and Facilities" (CIF) program led by PI Karen Kosiba.
Severe weather is any dangerous meteorological phenomenon with the potential to cause damage, serious social disruption, or loss of human life. Types of severe weather phenomena vary, depending on the latitude, altitude, topography, and atmospheric conditions. High winds, hail, excessive precipitation, and wildfires are forms and effects of severe weather, as are thunderstorms, downbursts, tornadoes, waterspouts, tropical cyclones, and extratropical cyclones. Regional and seasonal severe weather phenomena include blizzards (snowstorms), ice storms, and duststorms. Extreme weather phenomena which cause extreme heat, cold, wetness or drought often will bring severe weather events. One of the principal effects of anthropogenic climate change is changes in severe and extreme weather patterns.
The tornado outbreak of October 17–19, 2007 was a widespread tornado outbreak that took place across much of the eastern half of North America starting on October 17, 2007, and continuing into the early hours of October 19. The outbreak was also responsible for five deaths; three in Michigan and two in Missouri, plus many injuries. At least 64 tornadoes were confirmed including 16 on October 17 across six states including Texas, Oklahoma, Arkansas, Louisiana, Mississippi and Missouri with wind damage reported in Oklahoma, Kansas, Illinois, Iowa, Arkansas and Mississippi. On October 18, at least 48 tornadoes were confirmed across eight states including Florida, Alabama, Mississippi, Tennessee, Kentucky, Illinois, Indiana and Michigan, plus widespread straight line wind damage. Until 2010, this event held the record for largest tornado outbreak ever recorded in the month of October according to NOAA.
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.
The tornado outbreak sequence of May 2003 was a prolonged and destructive series of tornado outbreaks that affected much of the Great Plains and Eastern United States in early May 2003. 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; 338 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 401 tornadoes overall, of which 65 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.
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.
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 David Andra, 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).
