A supercell is a thunderstorm characterized by the presence of a mesocyclone, a deep, persistently rotating updraft. Due to this, these storms are sometimes referred to as rotating thunderstorms. Of the four classifications of thunderstorms, supercells are the overall least common and have the potential to be the most severe. Supercells are often isolated from other thunderstorms, and can dominate the local weather up to 32 kilometres (20 mi) away. They tend to last 2–4 hours.
From May 2 to 8, 1999, a large tornado outbreak took place across much of the Central and parts of the Eastern United States, as well as southern Canada. During this week-long event, 152 tornadoes touched down in these areas. The most dramatic events unfolded during the afternoon of May 3 through the early morning hours of May 4 when more than half of these storms occurred. Oklahoma experienced its largest tornado outbreak on record, with 70 confirmed. The most notable of these was the F5 Bridge Creek–Moore tornado which devastated Oklahoma City and suburban communities. The tornado killed 36 people and injured 583 others; losses amounted to $1 billion, making it the first billion-dollar tornado in history. Overall, 50 people lost their lives during the outbreak and damage amounted to $1.4 billion. For these reasons, the outbreak is known in Oklahoma as the May 3rd outbreak or the Oklahoma tornado outbreak of 1999.
This article lists various tornado records. The most "extreme" tornado in recorded history was the Tri-State tornado, which spread through parts of Missouri, Illinois, and Indiana on March 18, 1925. It is considered an F5 on the Fujita Scale, holds records for longest path length at 219 miles (352 km) and longest duration at about 3+1⁄2 hours, and held the fastest forward speed for a significant tornado at 73 mph (117 km/h) anywhere on Earth until 2021. In addition, it is the deadliest single tornado in United States history with 695 fatalities. It was also the second costliest tornado in history at the time, and when costs are normalized for wealth and inflation, it still ranks third today.
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.
The 1998 Comfrey–St. Peter tornado outbreak was an unseasonably-strong tornado outbreak which affected the Upper Midwest region of the United States on March 29, 1998. A strong area of low pressure combined with a warm front and favorable upper-level dynamics to produce 16 tornadoes across the region—14 in Minnesota and two in Wisconsin. Thirteen of the tornadoes in Minnesota were spawned by a single supercell thunderstorm. This supercell remained intact for approximately 150 miles (240 km) as it moved across the southern part of the state during the late-afternoon hours.
This page documents the tornadoes and tornado outbreaks that occurred in 2007, 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. Some tornadoes also take place in Europe, e. g. in the United Kingdom or in Germany.
This page documents notable tornadoes and tornado outbreaks worldwide in 2003. 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.
This page documents notable tornadoes and tornado outbreaks worldwide in 2001. 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 Corn Belt derecho was a progressive derecho which affected a large area of the central United States on June 29, 1998. In the morning, thunderstorms, including a supercell, developed over South Dakota and tracked into central Iowa. As the thunderstorms reached central Iowa, a strong rear-inflow jet developed which caused the thunderstorm to take on a different characteristic, becoming a derecho. It traveled more than 600 miles in about ten hours, causing more than $125 million worth of widespread damage destruction, especially to crops, and was responsible for power outages to nearly a half a million people.
This page documents the tornadoes and tornado outbreaks of 1999, 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 Northern Hemisphere's summer season, as well as Europe. One particular event, the Bridge Creek-Moore, Oklahoma F5 tornado, produced the highest wind speed ever recorded on Earth, which was 301 ± 20 mph (484 ± 32 km/h).
Tornadoes are more common in the United States than in any other country or state. The United States receives more than 1,200 tornadoes annually—four times the amount seen in Europe. Violent tornadoes—those rated EF4 or EF5 on the Enhanced Fujita Scale—occur more often in the United States than in any other country.
The Upper Great Lakes severe weather outbreak of August 23, 1998 was a severe weather outbreak that affected parts of Wisconsin, and the Upper Peninsula of Michigan. The outbreak occurred on August 23, 1998, and caused millions of dollars in damage to the region. One fatality is attributed to this severe weather event, when a severe thunderstorm knocked a tree onto a camper killing its sole occupant. A supercell spawned a F3 tornado that ripped across Door County causing $6.5 million in damages. It was the 8th most costly tornado in Wisconsin history injuring two people, destroying multiple structures and disrupting the regional economy and tourism. Two storms moved through the Fox Valley producing a minimal F0 tornado, but devastating amounts of hail. Damages from the hail were estimated to be around $5 million and damaged many structures and vehicles. Wisconsin Governor Tommy Thompson requested a Presidential Disaster Declaration from President Bill Clinton for the disaster, but was denied.
This page documents the tornadoes and tornado outbreaks of 1998, 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, however by the 1990s tornado statistics were coming closer to the numbers we see today.
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.
The 1999 Bridge Creek–Moore tornado was a large, long-lived and exceptionally powerful F5 tornado in which the highest wind speeds 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 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.
This page documents the tornadoes and tornado outbreaks of 2011. Extremely destructive tornadoes form most frequently in the United States, Bangladesh, Brazil and Eastern India, but they can occur almost anywhere under the right conditions. Tornadoes also appear regularly in neighboring southern Canada during the Northern Hemisphere's summer season, and somewhat regularly in Europe, Asia, and Australia.
A deadly and destructive outbreak sequence of 23 tornadoes struck parts of the Great Plains and the Great Lakes in late-June 1957. At least seven significant tornadoes (F2+) touched down during the outbreak sequence. The most devastating storm was a large, violent, and catastrophic 500-yard-wide F5 tornado family that struck Fargo, North Dakota on Thursday, June 20, 1957, killing 10 people and becoming the deadliest tornado ever recorded in North Dakota. The outbreak caused 11 fatalities, 105 injuries, and $25.883 million in damage.
Throughout the afternoon hours of May 21, 2024, a large, powerful, and destructive multi-vortex tornado struck the cities and communities of Villisca, Nodaway, Brooks, Corning, and Greenfield in southwestern Iowa, killing five people and injuring 35 others. The tornado was the strongest of the tornado outbreak sequence of May 19–27, 2024. 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).
A multi-day period of significant tornado activity along with significant derechos occurred across the Midwestern United States and the Mississippi Valley as well as an additional tornado in the Canadian province of Quebec. From May 19–27, 2024, two derechos occurred and tornadoes were reported across large portions of the Central United States, with multiple Particularly Dangerous Situation (PDS) watches issued across the sequence. On May 19, strong tornadoes occurred with isolated supercells in Colorado and Oklahoma while a derecho produced widespread wind damage and weak tornadoes across Kansas into the early morning hours of May 20. Limited tornadic activity took place on May 20, but another outbreak along with widespread damage struck mainly Iowa and Wisconsin on May 21. Five fatalities were confirmed with a large, violent, long-tracked EF4 tornado that went through Greenfield, Iowa. Scattered to widespread severe weather and tornadoes occurred over the next two days, including an EF2 tornado that injured 30 people on the west side of Temple, Texas. Another derecho formed in southwestern Nebraska late on May 23 and moved eastward, producing widespread wind damage and weak tornadoes through Nebraska and Iowa and northwestern Illinois before withering away in the northern part of the state during the morning hours of May 24.
