Identify the hazards in the message
Thunderstorms can bring several hazards at once. Read the warning for the specific concerns in your area, such as damaging winds, hail or flash flooding. A thunderstorm warning is not a rainfall forecast for one street. Check the affected area and the time window, and follow the official instructions linked from the alert.
Plan your next step indoors
If thunder is audible, move into a substantial building or an enclosed, hard-topped vehicle. Keep away from windows during severe wind or hail. Outdoor shelters, isolated trees and open vehicles do not provide the same protection. Choose a safe place before a storm reaches you, especially at an outdoor event.
Keep checking for updates
A storm may change as it moves. Keep an official warning channel available and do not rely only on a map tab that may be stale. If the warning includes a tornado or flooding threat, follow the instructions for that specific hazard. After the storm, avoid damaged trees, fallen power lines and floodwater.
A short checklist before storms are nearby
Decide where you will go if thunder starts: a substantial building is the first choice, and a hard-topped vehicle is a backup, not a picnic shelter or a tree. Postpone outdoor work that cannot stop quickly. Charge a phone and know how you will receive official alerts if the website is unavailable. Read the warning for hail, wind and flood threats separately. Heavy rain under a thunderstorm warning can create flash flooding even when the headline is about lightning or wind.
After the warning expires
The end of a warning window is not a promise that every hazard has ended. Fallen lines, weakened trees and water over roads can remain. Do not drive around barricades to “see the damage.” If the map no longer shows the polygon, confirm with the National Weather Service or your local emergency manager before you treat the area as back to normal.
Sources and further reading
Official National Weather Service reference. Source checked September 28, 2026. This general guide does not replace a current warning or advice from local authorities.
Check current warnings
Explore related live official warnings, or search your location for a forecast.