SkywarnTM is a proactive spotter network. During severe weather outbreaks, the
NWS activates SkywarnTM, and spotters in target areas are notified. SkywarnTM
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, receive weather information from ham radio operators
throughout the region, and forward them to the NWS forecasters..
www.weather.gov 
