Tornado Warning vs. Severe Thunderstorm Warning: What’s the Difference?
When your phone’s weather app buzzes or your TV cuts to an emergency alert, the words matter. A tornado warning and a severe thunderstorm warning are two different alerts issued by the National Weather Service, and they call for different — but overlapping — responses.
Severe Thunderstorm Warning
A Severe Thunderstorm Warning is issued by a local NWS Weather Forecast Office when a thunderstorm is producing or is expected to produce:
- Wind gusts of 58 mph or greater (measured at the surface), or
- Hail of 1.00 inch (quarter size) or larger in diameter.
This is a significant threshold. At 1.00″ hail, asphalt shingles begin to accumulate granule loss. At 58 mph, wind can damage trees, lightweight structures, and power lines.
What to do: Seek shelter in a substantial building. Move away from windows. Secure or bring in outdoor furniture. Avoid driving through areas with active lightning.
Tornado Warning
A Tornado Warning is issued when a tornado has been observed on the ground by storm spotters or emergency personnel, or when Doppler radar indicates rotation strong enough to suggest a tornado may be occurring or is imminent.
This is a more immediate threat than a Severe Thunderstorm Warning. A tornado warning means there is a confirmed or radar-indicated tornado affecting a specific county or area.
What to do: Seek shelter immediately. Move to the lowest floor of a sturdy building, preferably an interior room or basement. Do not wait to see the tornado. Mobile homes and manufactured homes are not safe shelter — evacuate immediately.
The Key Distinction
| Alert | Criteria | Immediate Action |
|——-|———-|—————–|
| Severe Thunderstorm Warning | 58 mph wind OR 1″ hail | Seek shelter in a building |
| Tornado Warning | Observed or radar-indicated tornado | Seek shelter immediately — no delay |
Tornado Emergencies and Particularly Dangerous Situations (PDS)
The NWS also issues two elevated variants:
- Tornado Emergency: Reserved for confirmed, large, extremely dangerous tornadoes affecting populated areas. Used rarely.
- Particularly Dangerous Situation (PDS) Tornado Watch: Issued when conditions are extremely favorable for significant, long-track tornadoes.
If you see either of these, treat the situation with maximum seriousness.
Why This Matters for Property Owners
A Severe Thunderstorm Warning is often the precursor to hail damage. If your area is under a severe thunderstorm warning with hail threat, move vehicles to a garage if possible. After the storm, use our Damage Calculator to estimate hail damage risk and our After-Storm Checklist to guide your inspection.
Sources: NWS Warning Criteria, NWS Tornado Safety
*FindTheTornado.com is an educational resource. We do not perform inspections, repairs, or insurance work.*