Tornado climatology
Tornadoes have been recorded on all continents except Antarctica and are most common in the middle latitudes where conditions are often favorable for convective storm development. The United States has the most tornadoes of any country, as well as the strongest and most violent tornadoes. A large portion of these tornadoes form in an area of the central United States popularly known as Tornado Alley. Other areas of the world that have frequent tornadoes include significant portions of Europe, South Africa, Philippines, Bangladesh, parts of Argentina, Uruguay, and southern and southeast Brazil, northern Mexico, New Zealand, and far eastern Asia.
Tornadoes in the United States
Hurricanes and other tropical storms can also generate tornadoes. Louisiana and the coastal regions of Mississippi and Alabama are most at risk from these storms. The Atlantic seaboard states can be affected too. According to NCDC figures for the 1950 to 2006 period, Mississippi reported 1,787 tornadoes, followed by Louisiana (1,644), Alabama (1,608), Arkansas (1,579), Georgia (1,324), North Carolina (1,042), Tennessee (892), South Carolina (819), Kentucky (710) and Virginia (565). West Virginia, by contrast, is one of the least vulnerable states of all with just 120 tornadoes reported over the period.