A 'tornado watch' indicates that atmospheric conditions are favorable for the development of tornadoes in and near the watch area; it is issued typically hours in advance by the Storm Prediction Center, urging people to stay informed and be prepared.

A 'tornado warning' means a tornado has been sighted or indicated by radar within the specified area; it is issued by local National Weather Service offices and requires immediate action, such as seeking shelter.

The key distinction: A watch signals potential ('time to review your safety plan'), while a warning signals imminent danger ('get to your safe place now').