View All Articles

Criteria For a Tornado Warning

The National Weather Service (NWS) is the official U.S. government agency charged with issuing severe weather watches, warnings, and advisories and is the source used by iAlert.com. When the NWS issues a “Tornado Warning” their decision is based on based on the following criteria….

Tornado Warning is Issued When:

  • A tornado is reported on the ground or is indicated by weather radar
  • A waterspout is headed for landfall
  • A rotating wall cloud, usually one that has strong low-level rotation, is reported.
  • A funnel cloud is reported.

Sample Radar Image Highlighting Tornado Location

  Regardless of the criteria for which a tornado warning is issued under, a tornado warning means there is immediate danger for the warned area and those in the storm path should take cover immediately. Although it is well known that tornados are most common in the mid-west United States, called tornado ally, tornados can and do occur in all 50 states. U.S. tornado warnings are generated through the NWS Advanced Weather Interactive Processing System (AWIPS) and disseminated through various communication channels including iAlert.com, the news media, NOAA Weather Radio, and where present Civil defense sirens are activated. A warning should not be confused with a tornado watch which indicates that conditions are favorable for the formation of tornadoes.

Related Articles:

This entry was posted in Weather Glossary and tagged , , , . Bookmark the permalink.

Leave a Reply

Read More

NOAA Storm Prediction Center categorical severe weather outlook for July 21, 2026, showing an Enhanced Risk (orange) over the Upper Ohio Valley into the Mid-Atlantic, ringed by Slight (yellow) and Marginal (green) risk areas across the eastern United States.

Upper Ohio Valley Severe Weather: Enhanced Risk July 21, 2026

Upper Ohio Valley severe weather is the headline threat on July 21, 2026, as the NOAA Storm Prediction Center (SPC) has issued an Enhanced Risk stretching from the Ohio Valley through the Mid-Atlantic and into the…

Read More

Upper Midwest severe thunderstorms categorical risk map for July 20, 2026, showing an SPC Enhanced Risk from Minnesota and Iowa across Wisconsin to the Great Lakes.

Upper Midwest Severe Thunderstorms: Enhanced Risk July 20, 2026

Upper Midwest severe thunderstorms are threatening Minnesota, Wisconsin, Iowa, Upper Michigan, and the broader Great Lakes region today, July 20, 2026, with the NOAA Storm Prediction Center placing the area under an Enhanced Risk, the third…

Read More

SPC Day 1 categorical severe weather outlook for July 19, 2026, showing Slight Risk areas for Southeast severe thunderstorms across the Carolinas, north Georgia, and southern Virginia, plus the Dakotas and western Minnesota.

Southeast Severe Thunderstorms and Dakotas Hail Threat: SPC Outlook for July 19, 2026

Southeast severe thunderstorms are the lead hazard in today's Storm Prediction Center Day 1 Convective Outlook, issued July 19, 2026, with the SPC placing a Slight Risk, the second of five severe categories (level 2 of…

Read More

Leave a Reply