A tornado is a violent rotating column of air that extends from a thunderstorm to the ground. The most violent tornadoes are capable of tremendous destruction and can have wind speeds of up to 300 mph. They have the capability to destroy even large buildings, uproot trees and hurl vehicles hundreds of yards. The damage caused by tornadoes can be in excess of one mile wide to 50 miles long.

In the USA during an average year there can be as many as 1000 tornadoes reported.

The majority of tornadoes form within thunderstorms. Warm, moist air is required and in the USA this comes from the Gulf of Mexico and then mixes with the cool, dry air from Canada. When these two air masses come together, they create instability in the atmosphere. This causes a change in the wind direction and an increasing wind speed, generating an upwards movement of height which in turn creates an invisible, horizontal spinning effect in the lower atmosphere. The rising air within the updraught then tilts the rotating air from horizontal to vertical creating an tornado. It is possible that an area of rotation can be 2 to 6 miles wide, extending through much of the storm. Most of the strong and violent tornadoes form within this area of a strong rotation.

For more information on tornadoes go to: - noaa.gov