Lightning TrackerSevere thunderstorm warning vs watch
A watch means severe storms are possible — be ready. A warning means a severe storm is happening or about to hit your area — act now. Below: every severe thunderstorm and tornado alert in effect right now.
Active severe thunderstorm and tornado alerts
Live alerts for the United States
Checking the National Weather Service…
Watch or warning — what's the difference?
| Watch | Warning | |
|---|---|---|
| Means | Severe storms are possible in and near the area | Severe weather has been reported by spotters or indicated by radar |
| Area | Large — many counties or even several states | Small — about the size of a city or small county |
| Issued by | NOAA Storm Prediction Center | Your local National Weather Service office |
| What to do | Stay informed, know where you'd shelter | Act now — get indoors, away from windows |
What makes a thunderstorm "severe"
The National Weather Service calls a storm severe when it produces hail an inch or larger — quarter size, see the hail size chart — or wind gusts over 58 mph. Lightning alone does not make a storm severe: every thunderstorm produces lightning, which is why there is no "lightning warning". Tornadoes get their own watches and warnings; a tornado warning means a tornado has been sighted or indicated by radar.
What to do when a warning is issued
- Get inside a sturdy building and stay away from windows and doors — large hail and flying debris break glass.
- Bring pets inside and, if there is time, move cars under cover.
- Avoid corded phones, plumbing and electrical equipment while lightning is nearby (lightning safety).
- If the warning mentions a tornado, or a tornado warning follows, go to a basement or an interior room on the lowest floor.
Warnings for your city
Every city page on this site shows the live NWS alerts for that exact location, a 48-hour thunderstorm outlook and the local history of hail, wind and tornado reports. Find yours with the search on the storm tracker home page.
Frequently asked questions
What is the difference between a severe thunderstorm watch and a warning?
A watch means severe thunderstorms are possible in and near the watch area, which typically covers many counties or even several states. A warning means severe weather has been reported by spotters or indicated by radar for a much smaller area, about the size of a city or small county, and indicates imminent danger to life and property.
What makes a thunderstorm severe?
The National Weather Service calls a thunderstorm severe when it produces hail one inch or larger (quarter size) or wind gusts over 58 mph. Storms can also produce tornadoes, which get their own warnings.
Who issues watches and warnings?
Watches for severe thunderstorms and tornadoes are issued by the NOAA Storm Prediction Center; warnings are issued by the local National Weather Service forecast office.
What should I do during a severe thunderstorm warning?
Move indoors to a sturdy building, away from windows. Large hail and damaging winds are expected or occurring. If a tornado warning is issued, go to a basement or an interior room on the lowest floor.
Sources
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Updated Sep 29, 2026.