Skywarn is a program used by trained weather spotters to report severe weather to the United States's National Weather Service.
While highly technical equipment is used to evaluate the weather, the data doesn't usually indicate specific localized occurrences (for example, flash floods, the formation of a funnel cloud, or the presence of hail). The spotters provide essential information that is helpful in providing severe warnings and watches, and documenting weather trends. Trained spotters often have an amateur radio license, and many national weather service offices have an amateur radio station within the facility to receive weather reports by individuals or networks of spotters. Participation in Skywarn does not require an amateur radio license, though. Spotters can report severe weather using a telephone or e-mail.
All skywarn spotters that complete a skywarn training class are issued a spotter ID. The first two letters indicates the county that the spotter resides in. The next number or numbers indicate the individual number of the spotter.
A local National Weather Service office may activate their amateur radio station in anticipation of severe weather, or after it issues any warnings. After the activation, skywarn spotters with amateur radio licenses can contact the local office to provide reports of severe weather.
Severe Thunderstorm reports include:
Winter weather reports include: