A tornado watch is a severe weather watch product of the National Weather Service that is issued by national weather forecasting agencies when meteorological conditions are favorable for the development of severe thunderstorms capable of producing tornadoes. In addition to the potential for tornado development,thunderstorms that develop within the watch area may contain large hail,straight-line winds,intense rainfall and/or flooding that pose a similar damage risk as the attendant tornado threat. A tornado watch does not mean a tornado is active or will appear,just that favorable conditions increases the likelihood of such happening. A watch must not be confused with a tornado warning.
A severe thunderstorm watch is a statement issued by weather forecasting agencies to advise the public that atmospheric conditions in a given region may lead to the development of severe thunderstorms within the region over several hours. The criteria for issuing a watch varies from country to country and may also include torrential rainfall and tornadoes. A watch may also be issued several hours ahead of the arrival of a mature and organized complex of storms,such as a mesoscale convective system.
A severe thunderstorm warning is a type of public warning for severe weather that is issued by weather forecasting agencies worldwide when one or more severe thunderstorms have been detected by Doppler weather radar,observed by weather spotters,or reported by an emergency management agency,law enforcement,or the general public. Unlike a watch,a warning is issued to areas in the direct path of active severe thunderstorms,that are expecting a direct impact typically within an hour. Severe thunderstorms can cause property damage and injury due to large hail,high winds,and flooding due to torrential rainfall. The exact criteria to issue a warning varies from country to country.
On April 10–12,1965,a devastating severe weather event affected the Midwestern and Southeastern United States. The tornado outbreak produced 55 confirmed tornadoes in one day and 16 hours. The worst part of the outbreak occurred during the afternoon hours of April 11 into the overnight hours going into April 12. The second-largest tornado outbreak on record at the time,this deadly series of tornadoes,which became known as the 1965 Palm Sunday tornado outbreak,inflicted a swath of destruction from Cedar County,Iowa,to Cuyahoga County,Ohio,and a swath 450 miles long (724 km) from Kent County,Michigan,to Montgomery County,Indiana. The main part of the outbreak lasted 16 hours and 35 minutes and is among the most intense outbreaks,in terms of tornado strength,ever recorded,including at least four "double/twin funnel" tornadoes. In all,the outbreak killed 266 people,injured 3,662 others,and caused $1.217 billion in damage.
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 1994 Palm Sunday tornado outbreak was the third notable US tornado outbreak to occur on Palm Sunday and the second to take place in the Southeastern United States. The outbreak produced 29 tornadoes from Texas to North Carolina,killing 40 people and injuring 491,and causing $140 million in damage. The deadliest storm of the outbreak,as well as in the US in 1994,was an F4 tornado that devastated Piedmont,Alabama. It struck the Goshen United Methodist Church right in the middle of the Palm Sunday service,collapsing the roof on the congregation and killing 20 people inside,including the Rev. Kelly Clem's 4-year-old daughter Hannah. Two other houses of worship were also destroyed mid-service. The supercell that formed this tornado tracked for 200 miles (322 km) to South Carolina.
This article describes severe weather terminology used by the National Weather Service (NWS) in the United States. The NWS,a government agency operating as an arm of the National Oceanic and Atmospheric Administration (NOAA) branch of the United States Department of Commerce (DoC),defines precise meanings for nearly all of its weather terms.
The Edmonton tornado of 1987,an event also known as Black Friday to Edmontonians,was a powerful and devastating tornado that ripped through the eastern parts of Edmonton,Alberta,Canada and parts of neighbouring Strathcona County on the afternoon of Friday,July 31,1987. It was one of seven other tornadoes in central Alberta the same day.
This page documents notable tornadoes and tornado outbreaks worldwide in 2006. 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,Argentina,Brazil and Australia. Tornadic events are often accompanied with other forms of severe weather,including strong thunderstorms,strong winds,and hail.
This article describes severe weather terminology used by the Meteorological Service of Canada,a branch within Environment and Climate Change Canada. The article primarily describes various weather warnings,and their criteria. Related weather scales and general weather terms are also addressed in this article. Some terms are specific to certain regions.
In weather forecasting in the United States,"particularly dangerous situation" (PDS) is enhanced wording used by the National Weather Service to convey special urgency in some watch or warning messages when there is a significant risk of extreme weather,most commonly from types of weather events that are usually less severe by comparison,such as a severe thunderstorm outbreak or flash flooding. It is used in the format "This is a particularly dangerous situation..." at the discretion of the issuing forecaster. A watch or warning bearing the phrase is referred to as a PDS watch or PDS warning as shorthand jargon.
A multi-day tornado outbreak affected the central plains of the United States from May 22–27,2008. It was also one of the largest continuous tornado outbreaks on record. A total of 173 tornadoes were confirmed,with the most intense activity occurring across the Great Plains. One person was killed when a large wedge tornado struck Windsor,Colorado,and two more deaths were reported in Pratt County,Kansas. One person was also killed near Hugo,Minnesota on May 25 and nine were killed by an EF5 tornado that destroyed most of Parkersburg,Iowa and a small subdivision of New Hartford,Iowa. Another fatality,caused by lightning related to the storms,occurred in central Kansas.
This page documents the tornadoes and tornado outbreaks of 2000,primarily in the United States. Most tornadoes form in the U.S.,although some events may take place internationally,particularly in parts of neighboring southern Canada during the summer season.
The Southern Ontario Tornado Outbreak of 2009 was a series of severe thunderstorms that spawned numerous tornadoes in Southwestern Ontario,Central Ontario and the Greater Toronto Area (GTA) on August 20,2009,and was the largest single-day tornado outbreak in Ontario history and the largest in Canadian history. During the afternoon and evening,19 tornadoes touched down with four of them producing F2 damage. One F2 struck the town of Durham where significant damage occurred and one person was killed;two F2s struck the city of Vaughan,just north of Toronto,damaging hundreds of homes;another F2 devastated apple orchards and resort areas near Thornbury. The number of tornadoes associated with this event surpasses that of August 2,2006,which saw 18 documented tornadoes. In addition,it was one of the most destructive and costly tornado events ever in the province,and included one fatality,one of only a handful of deadly tornadoes in Ontario's recent memory. At one point,over 10 million people in Southern Ontario,one-third of Canada's population,were placed under tornado watches and/or warnings as the storms rolled through.
From May 10–13,2010,a major tornado outbreak affected large areas of Oklahoma,Kansas,Missouri,and Arkansas,with the bulk of the activity in central and eastern Oklahoma. Over 60 tornadoes,some large and multiple-vortex in nature,affected large parts of Oklahoma and adjacent parts of southern Kansas and Missouri,with the most destructive tornadoes causing severe damage in southern suburbs of the Oklahoma City metropolitan area and just east of Norman,Oklahoma,where the fatalities were reported from both tornado tracks. The outbreak was responsible for three fatalities,all of which occurred in Oklahoma. Damage was estimated to be over $595 million in central Oklahoma alone.
The June 2010 Northern Plains tornado outbreak was one of the most prolific summer tornado outbreaks in the Northern Great Plains of the United States on record. The outbreak began on June 16,with several tornadoes in South Dakota and Montana. The most intense storms took place the following day across much of eastern North Dakota and much of Minnesota. The system produced 93 tornadoes reported across four states while killing three people in Minnesota. Four of the tornadoes were rated as EF4 on the Enhanced Fujita scale,the most violent tornadoes in a 24-hour period since there were five within 15 hours in the 2008 Super Tuesday tornado outbreak. This was the region's first major tornado outbreak of the year and one of the largest on record in the region,comparable to a similar outbreak in June 1992. The 48 tornadoes that touched down in Minnesota on June 17 marked the most active single day in the state's history. June 17 was the second largest tornado day on record in the meteorological summer,behind the most prolific day of the 2003 South Dakota tornado outbreak on June 24,2003.
Throughout the evening hours of April 9,2015,an extremely violent and long-lived multiple-vortex tornado tore through the communities near Rochelle and in Fairdale,Illinois. Part of a larger severe weather event that impacted the Central United States,the tornado first touched down in Lee County at 6:39 p.m. CDT (22:39 UTC). It progressed through the counties of Ogle,DeKalb,and Boone before finally dissipating at 7:20 p.m. CDT. Along the tornado's 30.14-mile (48.51 km) path,numerous structures were heavily damaged or destroyed,especially in the small town of Fairdale where two fatalities and eleven injuries were recorded. A few well-constructed homes were swept completely away,indicative of peak winds near 200 mph (320 km/h),the upper bounds of an EF4 tornado. In the aftermath of the event,hundreds of citizens assisted in cleanup and recovery efforts. Economic losses from the tornado reached $19 million.
This page documents notable tornadoes and tornado outbreaks worldwide in 2020. Strong and destructive tornadoes form most frequently in the United States,Argentina,Brazil,Bangladesh,and eastern India,but 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,Argentina,Australia and New Zealand. Tornadic events are often accompanied by other forms of severe weather,including strong thunderstorms,strong winds,and hail.
The May 2022 Canadian derecho was a high-impact derecho event that affected the Quebec City-Windsor Corridor,Canada's most densely populated region,on May 21,2022. Described by meteorologists as a historic derecho and one of the most impactful thunderstorms in Canadian history,winds up to 190 km/h (120 mph) as well as around four tornadoes caused widespread and extensive damage along a path that extended for 1,000 kilometres (620 mi).
