How Do Tornadoes Form?
The Short Answer: A tornado forms from a large thunderstorm. Inside thunderclouds, warm, humid air rises, while cool air falls--along with rain or hail. These conditions can cause spinning air currents inside the cloud. Although the spinning currents start out horizontal, they can turn vertical and drop down from the cloud--becoming a tornado. Heavy, dark clouds hang low, dumping buckets of rain and hail. Suddenly, a twisting column of gray drops from the bottom of the cloud. For a while it hangs suspended in the sky. Then it extends to the ground. When it touches, it goes even darker as its ferocious whirling winds pick up dust, debris, and—if the windspeeds are fast enough—cows, cars, roofs, mobile homes, trees, and anything else not well-anchored in the ground. A strong tornado can pick up massive objects like trucks and drop them many miles away. What makes a cloud create one of these powerful assaults to Earth's surface? How is it that a violent whirlwind can form in a clo
