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.
List of Canadian tornadoes and tornado outbreaks
The reported increase in numbers of tornadoes in recent years may reflect more reporting by citizens and media involvement rather than an actual increase in tornado occurrence (although some natural increase has not been ruled out), in addition to better detection technology i.e. Doppler weather radar and satellite imagery. The upswing could also be attributed to other factors, such as improved aerial and ground damage assessment after the fact in sparsely populated areas (particularly the case in remote parts of the Canadian Prairies and Northern Ontario, for example), better trained spotter capabilities and increased use of digital recording devices by citizens. Tornadoes in Canada are enough of a threat for a public warning system to be in place, overseen by the national weather agency, Environment Canada (EC).