A tornado is a violently rotating column of air that extends from a thunderstorm to the ground. Wind speeds in the most intense tornadoes can exceed 200 miles per hour, capable of leveling well-built structures.

Tornadoes form most often from supercell thunderstorms that possess a rotating updraft. The exact mechanisms of tornado formation are still an active research topic. They appear as funnel clouds when moisture condenses, yet the destructive vortex may be invisible if it is not filled with debris or condensation.

The Enhanced Fujita scale rates tornadoes by the damage they cause. Warnings are issued when rotation is detected by radar or reported by spotters. The safest action is to move to an interior room on the lowest floor of a sturdy building or to a purpose-built shelter.

• Violently rotating column of air
• Extends from storm to ground
• Can produce extreme winds
• Warned by radar and spotters