Tornado outbreak sequence of May 21–26, 2011
The tornado outbreak sequence of May 21–26, 2011 was one of the largest tornado outbreaks on record which affected the Midwestern and Southern regions of the United States. Most of the tornadoes developed in a corridor from Lake Superior southwest to central Texas; isolated tornadoes occurred in other areas. An especially destructive tornado destroyed one-third of Joplin, Missouri, resulting in 158 deaths and over 1,000 injuries. The Joplin tornado is the deadliest in the U.S. since April 9, 1947, when an intense tornado killed 181 in the Woodward, Oklahoma area. Tornado-related deaths also occurred in Arkansas, Kansas, Minnesota, and Oklahoma. Overall, the tornado outbreak resulted in 184 deaths, 6 of those non-tornadic, making it second only to the 2011 Super Outbreak as the deadliest since 1974, and the second costliest tornado outbreak in U.S. history behind that same April 2011 outbreak, with insured damage estimated at $4–7 billion.
Teton–Yellowstone tornado
The Teton–Yellowstone tornado was a rare high-altitude tornado which occurred on July 21, 1987 in the U.S. State of Wyoming. Rated at F4 on the Fujita scale, it was the strongest tornado ever recorded in the state. It was also the only recorded F4 tornado in Wyoming history. The tornado cut through a long, wide swath of the Teton Wilderness and Yellowstone National Park, and even crossed the Continental Divide. The damage occurred at elevations ranging from , making it the highest altitude violent tornado recorded in the United States. No human fatalities or injuries were recorded, but up to 1,000,000 trees were uprooted by the storm. The F4 rating was based on the severity of the tree damage in the worst affected areas. Huge swaths of trees were flattened, and many were stripped of leaves and limbs, with the trunks debarked. Topsoil was picked up and spattered against the bare trunks. Fujita noted that the tree damage was only comparable to that he had seen associated with some of the tornadoes from the 1974 Super Outbreak, as well as the April 1977 Birmingham tornado. Most of the damaged forest later burned in the Yellowstone fires of 1988.