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 of 2015
Throughout much of the first half of 2015, tornado activity was near record low mostly due to a continuous pattern of a trough in the east, which brought colder than average temperatures there, and a ridge in the west, which brought warmer than average temperatures in the west. The pattern changed, slightly, in late March and early April to allow for some severe weather. During May, a few large tornado outbreaks occurred, which led it to be the most active tornado month since April 2011, and the most active May since 2008. Due to a significant El Niño event, November and December were extremely active months with over 20 fatalities in December alone. 93 tornadoes were reported in December, well above average for that month. Furthermore, 2015 was the first year since 2011 to see a total of more than 1,000 tornadoes across the United States. In synopsis, 2015 was the first average or above average year in terms of the number of tornadoes since 2011.Final totals through December 31
There were 32 tornadoes reported in the U.S. in January, of which 27 were confirmed.