many countries have very bad weather. people worry about hevy rain , typhoons , and hurricanes . in many parts of the united states, people have to worry about another thing : tornadoes.
tornadoes are extreme weather events . like hurricanes and typhoons, it is the hight winds that cause damage. tornadoes usually occur in the spring and early summer. sometime , they appear when the weather is calm, but usually they occur on windy days. the weather usually becomes very cloudy and rainy right before a tornado.