Watch, Warning, and Advisory Definitions
Convective Definitions
- Tornado Watch
- The Storm Prediction Center (SPC) issues Public Tornado Watches to alert the public, media and emergency managers to organized thunderstorms forecast to produce three or more tornadoes or any tornado which could produce F2 or greater damage. The forecast event minimum thresholds should be at least 2 hours over an area of at least 8,000 square miles.
- Severe Thunderstorm Watch
- The Storm Prediction Center (SPC) issues Public Severe Thunderstorm Watches to alert the public, media and emergency managers to organized thunderstorms forecast to produce six and more hail events of 3/4 inch (penny) diameter or greater, or damaging winds of 50 knots (58 mph) or greater. The forecast event minimum thresholds should be at least 2 hours over an area of at least 8,000 square miles.
- Tornado Warning
- Tornado Warnings are issued when there is radar indication and/or reliable spotter reports of a tornado.
- Severe Thunderstorm Warning
- Severe Thunderstorm Warnings are issued when there is radar indication and/or reliable spotter reports of hail of 3/4 inch (penny) diameter or greater, and/or wind gusts of 50 knots (58 mph) or greater.
