SKYWARN is a program of the United States' National Weather Service (NWS). Its mission is to collect reports of localized severe weather. These reports are used to aid forecasters in issuing and verifying severe weather watches and warnings and to improve the forecasting and warning processes and the tools used to collect meteorological data. It consists of a network of severe storm spotters that observe weather conditions and make reports of severe weather to their local NWS offices. These spotters are regularly trained by personnel from the local NWS offices. In many areas, classes are conducted each spring in advance of the coming severe weather season.