<Table> <Tr> <Td> </Td> <Td> This article may require cleanup to meet Wikipedia's quality standards . The specific problem is: article is repetitive, and ungrammatical in key sentences; technical details are not explained Please help improve this article if you can . (September 2010) (Learn how and when to remove this template message) </Td> </Tr> </Table> <Tr> <Td> </Td> <Td> This article may require cleanup to meet Wikipedia's quality standards . The specific problem is: article is repetitive, and ungrammatical in key sentences; technical details are not explained Please help improve this article if you can . (September 2010) (Learn how and when to remove this template message) </Td> </Tr> <P> 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 . </P> <P> The United States averaged 1,274 tornadoes per year in the last decade while Canada reports nearly 100 annually (largely in the southern regions). However, the UK has most tornadoes per area per year, 0.14 per 1000 km2, although these tornadoes are generally weak, and many other European countries have a similar number of tornadoes per area . </P>

Where do tornadoes happen most in the world