A tornado warning means that a tornado has been spotted and is imminent. It is issued by the National Weather Service when they have observed rotation in the clouds or a tornado has been reported by spotters. During a tornado warning, people should take cover immediately.

A tornado watch is issued when conditions are favorable for tornadoes to form. It is issued by the National Weather Service when conditions are right for tornadoes to form. During a tornado watch, people should stay alert and be prepared to take cover if a tornado warning is issued.