Severe thunderstorm warning

A severe thunderstorm warning means a storm is producing, or about to produce, hail one inch across or larger (quarter size), wind gusts of 58 mph or more, or both, inside the warned area.

The damage threat tags

• No tag: the base warning, one-inch hail or 58 mph gusts.
• Considerable: hail of 1.75 inches (golf ball) or wind of 70 mph or more expected.
• Destructive: hail of 2.75 inches (baseball) or wind of 80 mph or more. These warnings also go out as an emergency alert to phones in the area.
• Tornado possible: the storm is not showing enough rotation for a tornado warning, but one could form quickly.

Each warning also states the hail size and wind speed forecasters expect. TornadoTrack shows both on the map and in the list.

What to do

• Get indoors, away from windows. Wind of 60 to 80 mph breaks windows and drops trees and power lines.
• Move cars under cover if you can do it before the storm arrives. Don't go out once it starts.
• If the warning says tornado possible, or a tornado warning follows, go to your tornado shelter.
• Lightning comes with every thunderstorm, warned or not. If you can hear thunder, you are close enough to be struck.