What is a tornado warning? Severe weather terms to know

Severe weather blew through Indiana, Northern Kentucky and Southwest Ohio Thursday according to the National Weather Service.
Severe weather blew through Indiana, Northern Kentucky and Southwest Ohio Thursday according to the National Weather Service.

The National Weather Service in Wilmington, Ohio, has issued a severe thunderstorm watch over the region until 4 p.m. Thursday.

A tornado warning implemented in Williamstown, Crittenden and Dry Ridge, Kentucky, has expired.

Heavy rainfall and thunderstorms are possible, as well as isolated tornados, damaging wind gusts and "golf ball-sized hail," according to the service.

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

What does a tornado watch mean?

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?

The Weather Service issues tornado warnings when a tornado is imminent. Take shelter immediately.

What is a severe thunderstorm?

Severe thunderstorms are defined by the National Weather Service 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: What is a tornado warning? What is a severe thunderstorm watch?