What's the difference between a tornado watch and a warning? Here's what to know

The National Weather Service at Wilmington announced a tornado watch just before 6 p.m. that includes the Greater Cincinnati area. The watch affects western Indiana, central Ohio, southwest Ohio and Northern Kentucky and expires at 1 a.m. Wednesday.

In Ohio, Cincinnati-area counties Hamilton, Warren, Butler and Clermont are under the watch. In Northern Kentucky, Campbell, Kenton and Boone counties are impacted.

What is a watch? Wondering what these terms mean and when to take cover? Here's what to know.

What does a tornado watch mean?

A tornado watch means "be prepared." Tornadoes are possible in and near the watch area. Review and discuss your emergency plans and check supplies and your safe room. Be ready to act quickly if a warning is issued or you suspect a tornado is approaching.

Watches are issued by the Storm Prediction Center for counties where tornadoes may occur. The watch area is typically large, covering numerous counties or even states.

A tornado watch is issued when severe thunderstorms and tornadoes are possible in and near the watch area. This doesn't mean they will occur.

What is a tornado warning?

A tornado warning means "take action now" as a tornado has been sighted or is indicated by weather radar. There is imminent danger to life and property. Move to an interior room on the lowest floor of a sturdy building. Avoid windows.

If in a mobile home, a vehicle, or outdoors, move to the closest substantial shelter and protect yourself from flying debris.

Your local forecast office issues warnings. Warnings typically encompass a much smaller area (around the size of a city or small county) that may be impacted by a tornado identified by a forecaster on radar or by a trained spotter/law enforcement who is watching the storm.

What is a severe thunderstorm?

The National Weather Service defines severe thunderstorms as having winds of 58 miles per hour or higher, and/or hail that is at least one inch in diameter.

What does a severe thunderstorm warning mean?

This warning is issued when severe thunderstorms are occurring or imminent in the warning area.

What is a severe thunderstorm watch?

A severe thunderstorm watch means a severe thunderstorm is possible in and near the watch area.

This article originally appeared on Cincinnati Enquirer: Tornado watch vs. warning: The meaning, differences between alerts