Tornadoes,, the natural disaster....

Tornadoes are among the most common disasters and specially they occur in USA....The United States receives more than 1,200 tornadoes annually.Although favorable conditions for tornadoes in the United States can occur at any time, they are most common in spring and least common in winter. Because spring is a transitional period for the climate, there are more chances of cooler air meeting with warmer air, resulting in more thunderstorms . Although the period in which most tornadoes strike ("tornado season") is March through August, tornadoes - including violent tornadoes and major tornado outbreaks - have been documented in the United States during every month of the years.