How do tornadoes form?

A tornado moving across the ground.

A tornado is a spinning column of air that touches the ground. How do tornadoes form? They form inside thunderstorms. Thunderstorms produce lots of rain and lightning. 

Photo Credit: ©Jason Weingart Photography

Tornadoes form inside thunderstorms.

Thunderstorms form when warm air near the ground rises. The warm air cools as it rises. A large cloud forms. Rain starts to fall towards the ground. Cool air also moves down toward the ground. 

In some thunderstorms, the air moving up and down starts to spin. The spinning air can sometimes move below the clouds. A funnel cloud (a spinning column of water droplets that comes down from the base of a thunderstorm) can form when that happens.

Photo Credit: NOAA/JPL-Caltech

A funnel reaching down from the cloud.

If a funnel touches the ground, it becomes a tornado. Most tornadoes last for about 10 minutes. Tornados can end if the thunderstorm gets too weak.

What Can You Do?  What happens to the air in a thunderstorm before a funnel cloud forms? 

Photo Credit: Willard Sharp/500px