A weather spotter is a person who observes significant weather and relays the information to the National Weather Service (NWS).

When spotters note a significant weather event, either from their homes or while on the road, they call an 800 number, give their spotter number and relay the information in a brief, to the_point message. Significant events can be heavy surf, waterspouts, strong winds, intense rain, snow, hail, thunderstorms, flooding, thick fog, extreme heat or cold, even tornadoes. Some areas within the forecast area have little or no sources of weather information. The spotter reports help fill those gaps that radar and satellites can't cover.

The spotters' data, which includes location, elevation and a description of the severity of the conditions, can help the NWS formulate and pinpoint advisories or warnings. When appropriate, the NWS gives the information to flood control agencies, the state Office of Emergency Services, the county Office of Disaster Preparedness, various police and fire departments, the California Highway Patrol and other agencies that deal with weather related emergencies.

Sometimes, the NWS will call a spotter for an observance if radar or satellite images indicate

something could be happening in an area, even if there have been no reports. Spotters can provide valuable confirmation.

The NWS' Skywarn^TM system is a similar but more sophisticated and proactive spotter network. During severe weather outbreaks, the NWS activates Skywarn^TM, and spotters in target areas are notified. Skywarn^TM spotters are then asked to relay observances from locations near potential trouble spots. Volunteer ham radio operators staff a station at the weather service office and receive weather information from ham radio operators throughout the region.