A warning issued by the National Weather Service means the hazardous weather is IMMINENT or OCCURRING. Warnings are issued for severe thunderstorms, tornadoes, flash floods, blizzards, hurricanes, and other phenomena.
A product issued by NWS local offices indicating that a particular weather hazard is either imminent or has been reported. A warning indicates the need to take action to protect life and property. The type of hazard is reflected in the type of warning (e.g., tornado warning, blizzard warning). See short-fuse warning.
The alerting of emergency response personnel and the public to the threat of extraordinary danger and the related effects that specific hazards may cause. A warning issued by the NWS (e.g., severe storm warning, tornado warning, tropical storm warning) for a defined area indicates that the particular type of severe weather is imminent in that area (FEMA definition). See also warning and forecasting; watch.