Tornado watch vs. warning
WARNINGS EXPLAINED
Who issues each alert, how long it lasts, what PDS and Tornado Emergency mean, and exactly what to do when your phone goes off.
Reviewed October 4, 2026. Sources are listed at the end of the page.
The short answer
A Tornado Watch means conditions are right for tornadoes, so get ready. A Tornado Warning means a tornado has been seen or shown on radar, so take shelter now. Watches come from the Storm Prediction Center, cover large areas and last about 6 hours. Warnings come from your local National Weather Service office, cover a small area and usually last under an hour.
Watch vs. warning at a glance
| Tornado Watch | Tornado Warning | |
|---|---|---|
| What it means | Conditions are favorable. Tornadoes are possible in and near the watch area. | A tornado has been sighted or indicated by weather radar. |
| Who issues it | The Storm Prediction Center in Norman, Oklahoma | Your local National Weather Service forecast office |
| How big | Large: often many counties, sometimes parts of several states (about 25,000 square miles) | Small: a polygon around the storm, about the size of a city or small county |
| How long | Usually about 6 hours | Usually less than an hour |
| What to do | Review your plan, charge phones, know where you will shelter, keep alerts on | Take shelter now: lowest floor, interior room, away from windows |
| Phone alert | No Wireless Emergency Alert | Every Tornado Warning triggers a Wireless Emergency Alert |
An easy way to remember it: a watch means watch the sky and get ready; a warning means act now.
The levels above a normal warning
Since the National Weather Service moved to impact-based warnings, a Tornado Warning can carry a damage threat tag. The tag tells you how dangerous the tornado is expected to be.
| Tag | Also called | When it is used |
|---|---|---|
| None (base warning) | Tornado Warning | Radar indicates a tornado or rotation, or there are reliable reports of one |
| Considerable | PDS (Particularly Dangerous Situation) Tornado Warning | Rare: a strong tornado is ongoing and poses a considerable threat to life and property |
| Catastrophic | Tornado Emergency | Exceedingly rare: a violent tornado is ongoing with a severe threat to life and catastrophic damage |
Watches have a stronger level too. A PDS Tornado Watch is an enhanced watch the Storm Prediction Center issues when conditions favor storms producing destructive tornadoes. If you are in one, have your shelter ready before storms arrive.
Where watches and warnings come from
The Storm Prediction Center watches the whole country and issues Tornado Watches hours ahead, when the ingredients for tornadoes come together. Once storms form, your local forecast office tracks each one on radar and issues Tornado Warnings for the specific storm and the area in its path. That is why a watch can sit over your county all afternoon while warnings come and go in short bursts.
On our live radar, active warnings are drawn as polygons over the storms that prompted them, so you can see exactly which storm a warning is for.
What to do in each
- Tornado Watch: decide where you will shelter, clear a path to it, put shoes and a flashlight there, charge phones, and make sure at least two ways of getting warnings are on. Set up alerts that wake you up if the watch runs overnight.
- Tornado Warning: go to your shelter immediately. Do not wait to see the tornado. See what to do in a tornado warning for houses, apartments, mobile homes and cars.
- Tornado Emergency: take the most protective shelter you can reach right now. A violent tornado is on the ground and damage has been confirmed.
Questions people ask
What is the difference between a tornado watch and a tornado warning?
A Tornado Watch means conditions are favorable for tornadoes in and near the watch area. A Tornado Warning means a tornado has been sighted or indicated by radar, and you should take shelter immediately.
Which is worse, a tornado watch or a tornado warning?
A Tornado Warning is more urgent. It means a tornado is happening or about to happen near you. A watch is a heads-up that one is possible.
How long does a tornado watch last?
Tornado Watches usually last about 6 hours and cover many counties. They can be extended or canceled early.
What is a Tornado Emergency?
It is the highest Tornado Warning level, used in exceedingly rare situations when a violent tornado is on the ground and threatening a populated area with catastrophic damage.
Do I get a phone alert for a tornado watch?
No. Wireless Emergency Alerts go out for every Tornado Warning, not for watches. To hear about watches, use a NOAA Weather Radio, a weather app, or free email or Messenger alerts.
Keep reading
Sources
- National Weather Service, Tornado Watch vs. Warning.
- National Weather Service, Tornado impact-based warnings.
- National Weather Service Jackson, MS, Severe weather product guide.