2011 Super Outbreak in the context of 1974 Super Outbreak

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 was likely an F5 on the Fujita Scale (tornadoes were not rated at the time) and holds records for longest path length at 219 miles (352 km) and longest duration at about 3+1⁄2 hours. The 1974 Guin tornado had the highest forward speed ever recorded in a violent tornado, at 75 mph (121 km/h). The deadliest tornado in world history was the Daulatpur–Saturia tornado in Bangladesh on April 26, 1989, which killed approximately 1,300 people. In the history of Bangladesh, at least 24 tornadoes killed more than 100 people each, almost half of the total for the world. The most extensive tornado outbreak on record was the 2011 Super Outbreak, which resulted in 367 tornadoes and 324 tornadic fatalities, whereas the 1974 Super Outbreak was the most intense tornado outbreak on tornado expert Thomas P. Grazulis's outbreak intensity score with 578, as opposed to the 2011 outbreak's 378.

The Joplin tornado was a devastating EF5 tornado that struck the city of Joplin, Missouri, United States early on the evening of Sunday, May 22, 2011, causing catastrophic damage to it and the surrounding regions. As part of a larger late-May sequence of tornadic activity, the extremely violent tornado began just west of Joplin at about 5:34 p.m. CDT (UTC–05:00) and quickly reached a peak width of nearly 1 mile (1.6 km) as it tracked through the southern part of the city, before later impacting rural Jasper and Newton counties and dissipating after 38 minutes on the ground at 6:12 p.m. The tornado was on the ground for a total of 21.62 miles (34.79 km).

The tornado devastated a large portion of the city of Joplin, damaging nearly 8,000 buildings and destroying over 4,000 houses. The damage—which included major facilities like one of Joplin's two hospitals as well as much of its basic infrastructure—amounted to a total of $2.9 billion (equivalent to about $4 billion today), making the Joplin tornado the costliest single tornado in U.S. history. The insurance payout was the highest in Missouri history, breaking the previous $2 billion record from the hailstorm of April 10, 2001. The tornado was the fifth out of six total EF5 tornadoes that occurred in 2011, with four having occurred a month earlier during the 2011 Super Outbreak, and only two days before the same outbreak sequence produced another EF5 tornado in El Reno, Oklahoma on May 24.

A tornado outbreak is the occurrence of multiple tornadoes spawned by the same synoptic scale weather system. The number of tornadoes required to qualify as an outbreak typically are at least six to ten, with at least two rotational locations (if squall line) or at least two supercells producing multiple tornadoes.

The tornadoes usually occur within the same day or continue into the early morning hours of the succeeding day, and within the same region. Most definitions allow for a break in tornado activity (time elapsed from the end of the last tornado to the beginning of the next tornado) of six hours. If tornado activity indeed resumes after such a lull, many definitions consider the event to be a new outbreak. A series of continuous or nearly continuous tornado outbreak days is a tornado outbreak sequence. In the United States and Canada, tornado outbreaks usually occur from March through June in the Great Plains, the Midwestern United States, and the Southeastern United States in an area colloquially referred to as Tornado Alley. A secondary less active and annually inconsistent tornado "season" in the U.S. occurs in late autumn. Tornado outbreaks can also occur during other times of the year and in other parts of the world. In Europe, tornado season typically peaks around the summer months, although windstorms can spawn tornadoes in other seasons as well.