KinwarnWhat is a tornado emergency? NWS warning levels explained
A tornado emergency is the most serious kind of tornado warning. The NWS uses it only in exceedingly rare cases, when a violent tornado capable of catastrophic damage is on the ground and is a severe threat to life. If one covers your area, take shelter immediately.
Not every National Weather Service warning carries the same level of danger. Many warnings now end with short tags that tell you how bad the storm is expected to be. The most serious tornado tag turns a warning into a tornado emergency.
How impact-based warnings work
The NWS calls these impact-based warnings. Each one spells out three things: the hazard, the source of the information, and the expected impact. At the bottom is a list of tags.
A warning with no damage threat tag is a base warning. It is the normal warning level, and it still means danger and calls for action. A damage threat tag adds urgency for unusually serious storms. When a warning is tagged destructive or catastrophic, an extra headline is added to the warning text. Some tags also trigger Wireless Emergency Alerts on phones in the warned area.
Tornado warning levels
| Tag | What it means | Phone alert (WEA)? |
|---|---|---|
| Base (no tag) | Radar shows a tornado or one forming, or there are reliable reports of one | Yes |
| Considerable (Particularly Dangerous Situation) | Rare: a strong tornado is on the ground, with a considerable threat to life and property | Yes |
| Catastrophic (Tornado Emergency) | Exceedingly rare: a violent tornado is on the ground, with catastrophic damage and a severe threat to life | Yes |
The NWS reserves a tornado emergency for cases where a reliable source confirms the tornado, or radar clearly shows a damaging one, such as by detecting debris in the air.
If a tornado emergency covers your area, get to the safest place you can right away. Do not try to outrun the tornado in a vehicle. Stay sheltered, and check for updates once you are safe.
Do not confuse these with a PDS tornado watch. The Storm Prediction Center uses Particularly Dangerous Situation wording on a watch in rare cases when long-lived, intense tornadoes are likely. A watch means tornadoes are possible. A warning means one is happening or about to. See tornado watch vs. warning.
Radar indicated vs. observed
Tornado warnings also tell you how the NWS knows about the tornado:
- Tornado…radar indicated means radar shows a tornado or a developing tornado, but it has not been confirmed.
- Tornado…observed means there is evidence of a tornado on the ground, either from radar (for example, detected debris) or from reliable reports.
Both call for the same action: take shelter now.
Severe thunderstorm warning levels
| Tag | Hail | Wind | Phone alert (WEA)? |
|---|---|---|---|
| Base (no tag) | 1 inch (quarter) | 58 mph | No |
| Considerable | 1.75 inches (golf ball) | 70 mph | No |
| Destructive | 2.75 inches (baseball) | 80 mph | Yes |
A storm can reach a level by hail, by wind, or both. A destructive warning describes an extremely dangerous storm with a severe threat to life and property. The NWS says about 10 percent of severe thunderstorms reach this level each year on average.
Flash flood warning levels
| Tag | What it means | Phone alert (WEA)? |
|---|---|---|
| Base (no tag) | Used most of the time, when flood damage is possible | No |
| Considerable | Used rarely, when flooding of unusual severity is happening or about to and urgent action is needed | Yes |
| Catastrophic (Flash Flood Emergency) | Used exceedingly rarely, when there is a threat to life and catastrophic damage, and water reaches levels rarely if ever seen | Yes |
Flash flood warnings also say whether the flooding is radar indicated or observed by trained spotters, law enforcement, media, or other reliable people.
What the tags mean for you
- Act on every warning. A base warning is still a warning. Do not wait for stronger wording before you move.
- The action stays the same. For a tornado, take shelter. For a flash flood, get to higher ground and stay out of the water. The tag tells you how serious the threat is.
- Your phone may stay quiet. Base and considerable severe thunderstorm warnings, and base flash flood warnings, do not trigger Wireless Emergency Alerts. Have another way to get warnings, as described in how to get tornado warnings.
See current warnings on the live tornado warning map.