A tornado, sometimes called a twister, consists of a rapidly rotating column of air that forms under a thundercloud or a developing thundercloud. A powerful tornado can lift cattle, automobiles, and even mobile homes into the air and destroy almost everything in its path. Fortunately, most tornadoes are relatively weak, and only a few are devastating. Scientists use the word cyclone to refer to all spiral-shaped windstorms that circulate in a counterclockwise direction in the Northern Hemisphere or in a clockwise direction in the Southern Hemisphere. The term cyclone comes from the Greek word for circle.
Cyclones come in many sizes.
Tornado Most tornadoes are small, intense cyclones. The United States has the highest incidence of tornadoes in the world. Most of these storms occur in a belt known as Tornado Alley that stretches across the Midwestern and Southern states, especially Texas, Oklahoma, Kansas, Nebraska, and Iowa. However, tornadoes also strike many other parts of the world. Australia ranks second to the United States in number of twisters, and many damaging tornadoes strike Bangladesh.