Tornadoes

Source: Tornado Alley Diagram | Wikimedia

Tornadoes are violently rotating columns of air that descend from thunderstorms and make contact with the ground. Typically, tornadoes only last a few moments, but some have lasted more than an hour and can travel great distances. Not every thunderstorm can spawn a tornado. It takes an extremely powerful storm produce one. Tornadoes are the 3rd most hazardous aspect of a thunderstorm. Tornado Alley is a generalized term used in the United States to describe the area of the Central Plains with the highest occurrences of tornadoes. There are other areas in the Southeast (Dixie Alley) and Midwest (Hoosier Alley) where there is a high instance rate of tornadoes because the occurrences of tornadoes can be measured in a variety of different ways: tracks, strength, counts, and over different time periods. Tornadoes can happen anywhere, regardless of terrain.