Manila, Philippines – Tornadoes have been reported on all continents except Antarctica. Wherever the atmospheric conditions are exactly right, the occurrence of a tornado storm is possible. However, some parts of the world are much more prone to tornadoes than others. They are most common on continents in the mid-latitudes where they are frequently associated with thunderstorms that develop in regions where cold polar air meets warm tropical air.
In terms of absolute tornado counts, the United States leads the list, with an average of over 1,000 tornadoes recorded each year. A distant second is Canada, with around 100 per year.
The United States experienced destructive and exceptionally deadly tornadoes in 2011. There were 1,691 tornadoes reported. Several tornado records were broken in 2011, including for greatest number of tornadoes in a single month (758 in April) and the greatest daily total (200, on April 27). May 22, 2011, the Joplin EF-5 tornado killed 158 people, and completely destroyed the majority of the city of Joplin, Missouri. The reasons for the spiking death tolls in recent years are more likely due to the rise in the population density, the number of mobile homes and the chance paths taken by a series of tornadoes that happened to target populated areas.
In the Philippines, Tornado occurrence is very prominent in Mindanao due to thunderstorms associated with the inter-tropical convergence zone. PAGASA also says that the occurrence of tornadoes in the country is usually during summer, but of lesser intensity as compared with those in the States. In June last year PAGASA reported that the weather disturbance that hit the New Manila area in Quezon City amid heavy rains and strong winds caused by southwest monsoon was a multiple vortex tornado.