Tornado Alley
Although the official boundaries of Tornado Alley are not clearly defined, its core extends from northern Texas, Oklahoma, Kansas, Nebraska, into South Dakota. States such as Missouri, Iowa, Minnesota, Wisconsin, Illinois, Indiana, and western Ohio are sometimes included in Tornado Alley. Some research suggests that tornadoes are becoming more frequent in the northern parts of Tornado Alley where it reaches the Canadian prairies.
Americas
Southeastern North America is well known for its occurrence of tornadoes and hurricanes, of which the vast majority of tornadoes occur in the United States' Tornado Alley. Often parts of the Caribbean are exposed to the violent effects of hurricanes. These weather systems are formed by the collision of dry, cool air from Canada and wet, warm air from the Atlantic.