Although tornadoes occur in many parts of the world, these destructive forces of nature are found most frequently in the U.S. east of the Rocky Mountains during the spring and summer months. A tornado is defined as a violently rotating column of air extending from a thunderstorm to the ground. The most violent are capable of tremendous destruction with wind speeds of 250 mph or more. Damage Paths can be in excess of one mile wide and 50 miles long.
Thunderstorms develop in warm, moist air in advance of eastward-moving cold fronts.
These thunderstorms often produce large hail, strong winds, and tornadoes. Occasionally, large outbreaks of tornadoes occur along strong frontal systems that form in the Central States and move east. Several states may be affected by numerous severe thunderstorms and tornadoes. Tornadoes occasionally accompany tropical storms and hurricanes that move over land. They are most common to the right and ahead of the path of the storm center as it comes ashore.