The U.S. region nickname for the central plains where tornadoes are especially common is Tornado Alley.
Tornado Alley is a loosely defined area of the central United States where tornado activity has historically been frequent. Common descriptions place its core across parts of Texas, Oklahoma, Kansas, Nebraska and nearby Great Plains states, although its boundaries vary by study and by the statistic being measured.
The nickname reflects a weather setup in which warm, humid air from the Gulf of Mexico can meet cool, dry air from the Rockies or Canada. Strong changes in wind speed and direction with height—called vertical wind shear—can help thunderstorms organize into rotating supercells capable of producing tornadoes.
There is no official government boundary for Tornado Alley, and the term is sometimes overused. Researchers also discuss regional areas such as Dixie Alley in the Southeast, where tornadoes can be especially dangerous because they may occur at night, in wooded terrain or during cooler seasons. Tornado Alley does not mean tornadoes occur only there.