Learn what a tornado emergency means, why it outranks a PDS tornado warning and what to do at once

What a tornado emergency is

The National Weather Service created the tornado emergency after a violent tornado hit the Oklahoma City area on May 3, 1999, because forecasters wanted warning wording that would get attention in the path of the worst tornadoes. It is issued only in rare cases, when a severe threat to human life and catastrophic damage are imminent or ongoing and a reliable source confirms a damaging tornado, either by sighting or by radar showing a strong signature such as a debris ball. The warning text carries the phrase TORNADO EMERGENCY.

Tornado emergency, PDS warning and tornado warning

NWS impact-based tornado warnings come in three tiers. The base warning is issued when radar indicates a tornado or reliable reports confirm one. The considerable tier, a particularly dangerous situation or PDS, is issued rarely, when a strong, ongoing tornado poses a considerable threat to life and property. The catastrophic tier is the tornado emergency, issued in exceedingly rare cases when a violent tornado capable of catastrophic damage is ongoing. All tornado warnings, including the base tier, trigger Wireless Emergency Alerts, so read the alert text to see which tier you have.

What a PDS tornado watch means

The Storm Prediction Center issues tornado watches for large areas. The words particularly dangerous situation are added to a watch in rare cases when long-lived, strong or violent tornadoes are possible. A PDS watch is not a warning: no tornado has to be on the ground. It is the signal to be ready to act the moment a warning is issued.

Which alert is worse

From least to most urgent, the National Weather Service lists the tornado watch, the tornado warning and the tornado emergency. A watch says tornadoes are possible, so review your plan and check your safe place. A warning says take action now. An emergency says seek shelter immediately.

What to do in a tornado emergency

In a sturdy building, go to an interior room on the lowest floor and stay away from windows. In a mobile home, a vehicle or outdoors, get to the nearest substantial shelter and protect yourself from flying debris. Do not try to outrun a tornado in a vehicle. Once you are safe, keep checking your local forecast for updates. Our tornado safety guide covers where to shelter in more detail.

Does an EF rating decide it

No. EF ratings come from damage surveys after the tornado, so they cannot decide a warning issued while it is happening. A tornado emergency depends on the confirmed threat to life and the damage that is happening or about to happen.

Tornado emergency list, 1999 to 2026

The Iowa Environmental Mesonet, which archives National Weather Service warnings, counts 322 tornado emergencies since the first one on May 3, 1999, in Oklahoma. The most in one year was 60 in 2011. The states with the most are Alabama (80), Mississippi (49), Tennessee (31), Kentucky (24), Missouri (20). The National Weather Service says offices used the wording inconsistently before the criteria were formalized, so early years are likely undercounted.

The 20 most recent

List current through Oct 28, 2026. Source: Iowa Environmental Mesonet archive of NWS tornado warnings. A listed warning is the warning that carried the tornado emergency wording, not a confirmed damage or casualty count.

Common questions

Sources

• NWS Glossary: Tornado Emergency
• NWS: Impact-Based Warnings, Tornado
• NWS Little Rock: What is a Tornado Emergency?
• NWS: Understand Tornado Alerts (watch, warning, emergency)
• NWS Glossary: Watch (including PDS watch)
• NWS: Understanding Event Tags (impact-based warnings)
• Iowa Environmental Mesonet: NWS tornado emergency archive

Reviewed by the Storm Incoming editorial team on October 28, 2026. Follow local emergency officials if their instructions differ.