NEXRAD or Nexrad is a network of 159 high-resolution S-band Doppler weather radars operated by the National Weather Service (NWS), an agency of the National Oceanic and Atmospheric Administration (NOAA) within the United States Department of Commerce, the Federal Aviation Administration (FAA) within the Department of Transportation, and the U.S. Air Force within the Department of Defense. Its technical name is WSR-88D.
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.
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).
The Cooperative Institute for Severe and High-Impact Weather Research and Operations (CIWRO) is one of 16 NOAA Cooperative Institutes (CIs), hosted at the University of Oklahoma. Before Oct. 1, 2021, it was known as the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS). The CIMMS/CIWRO, a research organization created in 1978 by a cooperative agreement between the University of Oklahoma (OU) and the National Oceanic and Atmospheric Administration (NOAA), promotes collaborative research between NOAA and OU scientists on problems of mutual interest to improve basic understanding of mesoscale meteorological phenomena, weather radar, and regional climate to help produce better forecasts and warnings that save lives and property. CIMMS/CIWRO research contributes to the NOAA mission through improvement of the observation, analysis, understanding, and prediction of weather elements and systems and climate anomalies ranging in size from cloud nuclei to multi-state areas.
Volumetric Imaging and Processing of Integrated Radar, known by the acronym VIPIR, is an analysis and display program for Doppler weather radar, created and sold by Baron Services. This software allows improved analysis of radar data for private users, in particular television stations, similar to the Weather Decision Support System program used by the National Weather Service.
Convective storm detection is the meteorological observation, and short-term prediction, of deep moist convection (DMC). DMC describes atmospheric conditions producing single or clusters of large vertical extension clouds ranging from cumulus congestus to cumulonimbus, the latter producing thunderstorms associated with lightning and thunder. Those two types of clouds can produce severe weather at the surface and aloft.
A tornadic vortex signature, abbreviated TVS, is a Pulse-Doppler radar weather radar detected rotation algorithm that indicates the likely presence of a strong mesocyclone that is in some stage of tornadogenesis. It may give meteorologists the ability to pinpoint and track the location of tornadic rotation within a larger storm, and is one component of the National Weather Service's warning operations.
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.
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.
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.
Leslie R. Lemon was an American meteorologist bridging research and forecasting with expertise in weather radar, particularly regarding severe convective storms. Lemon was, along with Charles A. Doswell III, a seminal contributor to the modern conception of the supercell convective storm which was first identified by Keith Browning, and he developed the Lemon technique to estimate updraft strength and thunderstorm organization also as a continuation of Browning's work.
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).
Adam James Clark is an American meteorologist at the Cooperative Institute for Mesoscale Meteorological Studies (CIMMS) and the National Severe Storms Laboratory (NSSL) recognized for contributions to numerical modeling of convection.
Yvette Richardson is an American meteorologist with substantial contributions on tornado dynamics, tornadogenesis, the environments of tornadoes, supercells, and severe convection, and radar observations of these. She was a principal investigator (PI) of VORTEX2.
Alan Roger Moller was an American meteorologist, storm chaser, nature and landscape photographer known for advancing spotter training and bridging operational meteorology with research.
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).
Edwin Kessler III was an American atmospheric scientist who oversaw the development of Doppler weather radar and was the first director of the National Severe Storms Laboratory (NSSL).
Richard James Doviak was an American engineer and university professor, pioneer of weather radar. He worked for the National Oceanic and Atmospheric Administration at the National Severe Storms Laboratory developing the NEXRAD radar array using reflectivity, the Doppler effect and the dual polarization to detect precipitation and its movement in clouds. He is also the co-author with Dusan S. Zrnic of the reference book “Doppler Radar and Weather Observations” about modern weather radar and its use.
John C. "Chris" Broyles is an American meteorologist who is a weather forecaster and tornado forecasting expert with the Storm Prediction Center.
In the afternoon hours of June 5, 2009, a well-documented tornado moved across Goshen County, located in the state of Wyoming. The tornado was observed by hundreds of experimental radar instruments, and the event formed the pinnacle of the VORTEX projects, which aimed to document the formation and lifecycle of a tornado. The tornado and the observations of it were heavily studied by meteorologists in the following years, and footage of the tornado has been featured on several national television networks, including The Weather Channel.
