New Page 1 Almost seventy-five percent of all tornadoes form from March to July. The word Tornado comes from the Spanish word Tronada, meaning thunderstorm. A tornado over water is called a waterspout. Tornadoes usually last for a few minutes, and rarely last for more than an hour.
Tornadoes are cyclonic winds, and they rotate at very high speeds around a low-pressure center.
Tornadoes are smaller than hurricanes and are shorter lasting. A tornado can be as little as 100 feet to as much as 1.5 miles wide. The smallest tornadoes are called minis and the largest tornadoes are called maxis. A mini will last no longer than a few minutes, travel about a half a mile and have wind speeds up to 100 miles an hour. Maxis may travel 200 miles or more, last up to 3 hours, and have wind speeds of more than 250 miles per hour.