A tornado is a small intense storm. About six to seven hundred tornadoes are reported in the U.S. every year. Some people call tornadoes twisters or cyclones. Their damage areas are generally a few hundred feet wide and a few miles long. Most tornadoes happen in spring or summer. Tornado is made from the Spanish word tronada which means thunderstorm. Most tornadoes are in the U.S. Texas holds the record for the most tornadoes. A tornado over water is called a waterspout.