There are few sights in nature more terrifying than a powerful tornado. These violently rotating columns of air can reach from a storm cloud to the ground, and are normally visible due to condensation, as well as the dust and debris they pick up. Many tornadoes occur in an area known as “tornado alley,” but most last only for a few minutes and have wind speeds of 100 mph or less. However, the most destructive tornadoes can occur outside of tornado alley and last for more than an hour, with wind speeds of between 200 and 300 mph. The most violent tornadoes can toss automobiles into the air, rip homes off their foundations, and turn loose debris into lethal missiles. Tornado alley was coined back in 1952 and extends from northern and central Texas and Oklahoma northward to Kansas, Nebraska and South Dakota. The reason tornado alley experiences some of the world's largest tornado outbreaks is because of the region's proximity to warm, moist sources, like the Gulf of Mexico, as well as cold air from higher terrain to the west. The combination and layering of these disparate air masses results in both instability and wind shear. On average, about 33 tornadoes are reported annually in tornado alley. Not only does the United States have the most tornadoes of any country in the world — an average of 1,000 per year — it also has the most violent tornadoes.
