A tornado is a rotating column of air that comes out of a cumuliform cloud and usually takes the shape of a funnel. In order to be classified as a tornado, the funnel must be attached to the cloud and the ground at all times.

Tornadoes form when warm air from the Gulf of Mexico comes in contact with cold air from the Canadian Rockies. That is why they most often occur in the Midwest and Southeast sections of the United States. Most tornadoes in the Midwest move from Southwest to Northwest, or from west to east. Tornadoes in the Northern hemisphere (where we are) mostly rotate cyclonically, or counterclockwise.

Tornadoes sometimes form from thunderstorms. To read more about thunderstorms, click here.

When a tornado is occuring, or is about to occur, there is usually a drop in the barometer, which means that it is a LOW pressure storm. This drop in the barometer can happen a few days, or even a few minutes, before a storm. This is why it is very difficult to predict a tornado.

Tornados can do a lot of damage. Winds in a tornado are often greater than those in a hurricane. These winds do most of the damage because they can rip houses, roads, and trees apart. The winds in a tornado can sometimes pick something up and drop it more than a MILE away. Also, tornadoes can last for a few seconds, or for more than an HOUR.

Below are some maps showing where tornadoes usually take place. The Gulf of Mexico is between Florida and Texas. The Rocky Mountains are west of the "Tornado Alley".