Warn-on-Forecast (WoF or WoFS) is an ongoing research project being conducted by the National Severe Storms Laboratory (NSSL), a branch of the National Oceanic and Atmospheric Administration, designed to increase the lead time for tornado warnings, severe thunderstorm warnings, and flash flood warnings. [1] [2] [3] [4]
The research project was started in 2016 in the National Weather Center in Norman, Oklahoma. [5]
On May 16, 2017, a deadly EF2 tornado struck Elk City, Oklahoma. Before the tornado formed, meteorologists at the National Weather Service Norman, Oklahoma (NWS Norman) office saw storms form in Texas. NSSL, who works in the same building as NWS Norman, had a meteorologist embedded with the NWS Norman meteorologists. The Warn-on-Forecast system, which was being monitored by the NSSL meteorologist, noted a high chance of a tornado occurring in the Elk City area well before the tornado occurred. As a result, the National Weather Service issued a Significant Weather Advisory which stated, “Severe weather is likely with these storms as they move into Oklahoma and there is a high probability that tornado warnings will be issued.” Following the advisory being issued, the Elk City Emergency Manager, Lonnie Risenhoover, activated the tornado sirens to warn residents of Elk City nearly 30 minutes before the tornado struck. NWS Norman subsequently issued a tornado warning for Elk City, which was in place 28 minutes before the tornado struck. This was the first time WoFS influenced real time tornado warnings from the National Weather Service. [6]
In May 2018, tests were conducted alongside meteorologists at the NWS Norman office. [5]
On May 21, 2024, a violent EF4 tornado struck the city of Greenfield, Iowa. A few weeks after the tornado, the National Oceanic and Atmospheric Administration released details about an experimental warning system which was tested before and during the tornado. This new warning system, named Warn-on-Forecast System (WoFS), was created by the Hazardous Weather Testbed housed in the National Weather Center in Norman, Oklahoma. During the experiment and test, the WoFS gave a high indication of “near-ground rotation” in and around the area of Greenfield, Iowa between 2-4 p.m. According to the press release, 75-minutes later, the violent EF4 tornado touched down. Scientists with the National Severe Storms Laboratory were able to give local National Weather Service forecasters a 75-minute lead time for the tornado. [7] [8]
A tornado warning is a public warning that is issued by weather forecasting agencies to an area in the direct path of a tornado, or a severe thunderstorm capable of producing one, and advises individuals in that area to take cover. Modern weather surveillance technology such as Doppler weather radar can detect rotation in a thunderstorm, allowing for early warning before a tornado develops. They are also commonly issued based on reported visual sighting of a tornado, funnel cloud, or wall cloud, typically from weather spotters or the public, but also law enforcement or local emergency management. When radar is unavailable or insufficient, such ground truth is crucial. In particular, a tornado can develop in a gap of radar coverage, of which there are several known in the United States.
These are some notable tornadoes, tornado outbreaks, and tornado outbreak sequences that have occurred around the globe.
The Storm Prediction Center (SPC) is a US government agency that is part of the National Centers for Environmental Prediction (NCEP), operating under the control of the National Weather Service (NWS), which in turn is part of the National Oceanic and Atmospheric Administration (NOAA) of the United States Department of Commerce (DoC).
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).
A tornado emergency is an enhanced version of a tornado warning, which is used by the National Weather Service (NWS) in the United States during imminent, significant tornado occurrences in highly populated areas. Although it is not a new warning type from the NWS, issued instead within a severe weather statement or in the initial tornado warning, a tornado emergency generally means that significant, widespread damage is expected to occur and a high likelihood of numerous fatalities is expected with a large, strong to violent tornado.
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 1999 Bridge Creek–Moore tornado was a large, long-lived and exceptionally powerful F5 tornado in which the highest wind speed ever measured globally was recorded at 321 miles per hour (517 km/h) by a Doppler on Wheels (DOW) radar. Considered the strongest tornado ever recorded to have affected the Oklahoma City metropolitan area, the tornado devastated southern portions of Oklahoma City, Oklahoma, United States while near peak intensity, along with surrounding suburbs and towns to the south and southwest of the city during the early evening of Monday, May 3, 1999. Parts of Bridge Creek were rendered unrecognizable. The tornado covered 38 miles (61 km) during its 85-minute existence, destroying thousands of homes, killing 36 people, and leaving US$1 billion in damage, ranking it as the fifth-costliest on record not accounting for inflation. Its severity prompted the first-ever use of the tornado emergency statement by the National Weather Service.
A significant and destructive tornado outbreak that affected parts of the Midwestern United States and lower Great Plains in mid-May 2013. This event occurred just days after a deadly outbreak struck Texas and surrounding southern states on May 15. On May 16, a slow moving trough crossed the Rockies and traversed the western Great Plains. Initially, activity was limited to scattered severe storms; however, by May 18, the threat for organized severe thunderstorms and tornadoes greatly increased. A few tornadoes touched down that day in Kansas and Nebraska, including an EF4 tornado near Rozel, Kansas. Maintaining its slow eastward movement, the system produced another round of severe weather nearby. Activity significantly increased on May 19, with tornadoes confirmed in Oklahoma, Kansas, Iowa, Missouri, and Illinois. In Oklahoma, two strong tornadoes, one rated EF4, caused significant damage in rural areas of the eastern Oklahoma City metropolitan area; two people lost their lives near Shawnee. The most dramatic events unfolded on May 20 as a large EF5 tornado devastated parts of Moore, Oklahoma, killing 24 people. Thousands of structures were destroyed, with many being completely flattened. Several other tornadoes occurred during the day in areas further eastward, though the majority were weak and caused little damage.
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 tornado outbreak of June 16–18, 2014, was a tornado outbreak concentrated in the Great Plains and the Midwestern United States. Two tornadoes also occurred in Ontario. The severe weather event most significantly affected the state of Nebraska, where twin EF4 tornadoes killed two and critically injured twenty others in and around the town of Pilger on the evening of June 16. The two Pilger tornadoes were part of a violent tornado family that produced four EF4 tornadoes and was broadcast live on television. The outbreak went on to produce multiple other strong tornadoes across the northern Great Plains states throughout the next two days.
National Weather Service - Pleasant Hill/Kansas City, Missouri is a Weather Forecast Office (WFO) of the National Weather Service, which is responsible for forecasts and the dissemination of weather warnings and advisories for 37 counties in northern and western Missouri and seven counties in extreme eastern Kansas, including the Kansas City and St. Joseph metropolitan areas. Though, as the Storm Prediction Center (SPC) in Norman, Oklahoma is responsible for issuing severe thunderstorm and tornado watches, the Pleasant Hill/Kansas City WFO only composes outline and status updates for SPC-issued watches affecting any portion of its designated County Warning Area.
This page documents notable tornadoes and tornado outbreaks worldwide in 2024. Strong and destructive tornadoes form most frequently in the United States, Argentina, Southern Brazil, the Bengal region and China, but can occur almost anywhere under the right conditions. Tornadoes also develop occasionally in southern Canada during summer in the Northern Hemisphere and somewhat regularly at other times of the year across Europe, South Africa, Japan, Australia and New Zealand. Tornadic events are often accompanied by other forms of severe weather, including thunderstorms, strong winds and hail.
On the afternoon of May 21, 2024, a violent, destructive and powerful multi-vortex tornado struck the communities of Villisca, Nodaway, Brooks, Corning, and Greenfield in southwestern Iowa, killing five people and injuring 35 others. The tornado was the strongest of a large widespread tornado outbreak that occurred from May 19-27, 2024 in the central United States. The tornado reached peak intensity in the city of Greenfield, leading the National Weather Service in Des Moines, Iowa to assign a rating of mid-range EF4 on the Enhanced Fujita scale, with maximum wind speeds estimated at 185 mph (298 km/h). However, winds of 309–318 mph (497–512 km/h) were measured in a sub-vortex of the tornado by a DOW, placing it among the strongest tornadoes ever measured.
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.
John C. "Chris" Broyles is an American meteorologist who is a weather forecaster and tornado forecasting expert with the Storm Prediction Center.