Keywords: Tornado Alley.png A map of the frequency of F3 and greater intensity tornadoes by area The darker colors highlight the area typically known as Tornado Alley Source Image from a booklet from http //www fema gov/index shtm Federal Emergency Management Agency a United States government agency titled http //www fema gov/plan/prevent/saferoom/tsfs02_torn_activity shtm Taking Shelter from the Storm Building a Safe Room Inside your House FEMA 320 Figure 1 1 page 3 and thought to be in the public domain Area 700x522 pix PD-USGov Maps of North Americian tornadoes |