The National Weather Service's SKYWARN Program
SKYWARN is a plan sponsored by the National Weather Service (NWS), using volunteer weather observers for reporting destructive thunderstorms or other severe, unusual, or hazardous weather conditions. Amateur radio operators and weather observers, generally operating through local organizations, are ideally equipped to contribute to the SKYWARN program. [From The National Weather Service's Skywarn Spotter's Guide.]
The Westchester County SKYWARN severe weather spotting net operates on the 147.060 WB2ZII/R repeater as needed. Training sessions for SKYWARN spotters are usually provided by the National Weather Service twice a year at the County Emergency Operations Center.
SKYWARN weather net activations for our area are announced on NOAA Weather Radio, 162.55 MHz. Severe weather alerts are encoded with the new Specific Area Message Encoding (SAME) digital code and the old-style 1050 Hz alerting tone, which many weather radios are equipped to listen for. A table of regional FIPS state and county codes has been prepared so that you can properly configure one of these new weather radios, such as the Radio Shack model 12-249 7-Channel Weatheradio with NWR-SAME Severe-Weather Alert.
Note that a SKYWARN alert is a good first indication that there may be an ARES/RACES callup as the most frequent type of emergency that requires amateur radio assistance in this region is caused by severe weather (coastal flooding, high wind damage, heavy snow).
A short glossary of weather terms has been provided here by the National Weather Service office in Upton, NY (at the Brookhaven National Lab).
For more detailed information about SKYWARN, see the Brookhaven, NY National Weather Service Forecast Office or the National SKYWARN pages.