Watch, Warning and Advisory Criteria

The National Weather Service uses a WATCH and WARNING program to alert the public to potentially threatening weather. In the summertime, watches and warnings are issued for severe thunderstorms, tornadoes, and flash floods, and special marine warnings are issued for gusty winds in marine areas.

  • WATCH indicates that the atmospheric conditions are favorable for severe weather to develop. If a WATCH has been issued for your area, keep an eye on the sky, and monitor NOAA Weather Radio or your local broadcast media for any possible warnings.
  • WARNING indicates that severe weather is imminent in or is already occuring. If a WARNING has been issued for your area, be prepared to seek a safe shelter if you are in the path of the storm.

Basic Definitions of Events

  • SEVERE THUNDERSTORM - A thunderstorm that produces damaging wind gusts of 58 mph or more, and/or hail 3/4 inch or greater in diameter.
  • TORNADO - A violently rotating column of air that extends from a cloud to the ground.
  • FLASH FLOOD - Flooding that occurs very rapidly, usually due to very heavy rain from a slow moving thunderstorm.

In addition to these warnings which are issued for land areas, the National Weather Service issues Special Marine Warnings for marine areas.

  • SPECIAL MARINE WARNING - Issued for marine areas for storms with frequent wind gusts of 34 kts (about 39 mph) or greater.

One of the best ways to monitor these conditions is by purchasing an alert-activated NOAA Weather Radio for your home or business.