Tornadoes in the United States
The Midwestern states are very prone to tornado activity, as they are part of "Tornado Alley." States included in the area that are hit by tornadoes the most are Oklahoma, Kansas, Missouri, Nebraska, Iowa, and South Dakota. The Midwestern States are often hit by tornadoes during the late spring and early summer months, especially the months of May and June. This is due to the aforementioned air mass moving northward into the Midwest and combining with another air mass that move southward from Canada. This creates unstable air, creating the potential for storms to strike the most during these months. The frequency begins to decrease in the middle of the summer, as the air mass moves northward into the Great Lakes states.
History of the Kansas City metropolitan area
Although the Kansas City area, which is in Tornado Alley, is usually hit with at least one and often many more tornadoes each year, two major non-tornadic storms had profound effects on the city. On September 12, 1977, following a soggy summer, of rain fell on Kansas City, causing severe flooding across the entire region. The most dramatic flooding was in the Country Club Plaza neighborhood, along Brush Creek. The storm killed 25 people, and caused nearly $100 million in property damage. On June 4, 1979, a severe thunderstorm that moved through the city that evening collapsed the roof of Kemper Arena. As the area was not holding an event that night, no one was injured at the facility. Initial reports indicated that the collapse was the result of a downburst. However, an investigation later revealed that heavy rain from the storm had collected on the arena's roof, to the point where the supports were unable to handle the weight of the pooled water coupled with high winds that rocked its exterior skeleton. The arena was repaired and reopened in early 1980.