Most communities host citizen operated weather watch groups to help warn of impending or current severe weather.
Skywarn. Skywarn is an organization of trained volunteers who report severe weather events to the National Weather Service. The NWS uses the input from spotters to help them issue more accurate public watches and warnings. Although the weather service uses radar to watch the skies, radar can only see in a straight line, and the earth's curvature causes a blind space to occur the farther away from the radar's location that you get. Therefore, storm spotters can see what the radar cannot see or can confirm radar-indicated events. Any willing individual can become a Skywarn storm spotter (Skywarn).
Amateur Radio. Amateur radio operators, often called Hams, are especially useful as they conduct coordinated operations during times of severe weather. Many are also members of SKYWARN. Most communities have one or more local amateur radio (ham) clubs that organize radio operators for public service communications functions. Amateur radio offers versatile and extended range communication abilities. Classes are available for earning your operator's license. Non-hams may also find the amateur radio frequencies interesting and informative to listen to.
NOAA Weather Radio. NWR is a nationwide network of radio stations broadcasting continuous weather information direct from a nearby National Weather Service office as a public service by the NOAA. Warnings, watches, forecasts, and other hazards are broadcast 24 hours a day. A weather radio provides an inexpensive, convenient way to monitor local weather. (National Weather Service)