<human>:  Explain the mechanics of how a tornado works.
<bot>: A tornado is a powerful and destructive column of rapidly rotating air that forms underneath thunderstorms. It is created by a combination of extremely low pressure at the base of a thunderstorm and powerful wind shear, which is the rapid change of wind speed and direction in a short distance. As the storm's updraft rises, the air is forced to rotate due to the air's high speed winds, and when the wind reaches the ground, its momentum causes the air to spin faster. The result is a rapidly rotating column of air reaching from the base of the thunderstorm down to the ground, at speeds of up to 300 mph or more. This intense velocity causes destruction in its path due to the strong winds and lifting of loose objects. The tornado can last from a few seconds to more than an hour, and its destruction can range from minor damage to total destruction.