NOAA Weather Radio is a service of the National Oceanic and Atmospheric Administration (NOAA) of the U.S. Department of Commerce. As the official "Voice of the National Service," it provides continuous broadcasts of the latest weather information local National Weather Service offices. Weather messages are repeated every 4 to 6 and are routinely updated every 1 to 3 hours or more frequently in rapidly local weather or if a nearby hazardous environmental condition exists. Most , including the National Weather Service Office in Billings operate 7 days a , 24 hours a day.

The regular broadcasts are specifically tailored to the weather information needs of people within the service area of the transmitter. For example, in addition to general weather information such as hydrological forecasts and climatological data may also be broadcast.

During severe weather, National Weather Service forecasters can interrupt the routine weather broadcasts and insert special warning messages concerning imminent threats to life and property. The forecaster can also add special signals to warnings that trigger "alerting" features of specially equipped receivers. In the simplest case, this signal activates audible or visual alarms, indicating that an emergency condition exists within the broadcast areas of the station being monitored and alerts the listener to turn up the volume and stay tuned for more information. More sophisticated receivers are automatically turned on and set to an audible volume when an alert is received.

In the most sophisticated alerting system, Weather Radio Specific Area Message Encoding (SAME), digital coding is employed to activate only those special receivers programmed for specific emergency conditions in a specific area, typically a county. SAME can activate specially equipped radio and television receivers and provide a short text message that identifies the location and type of emergency. This system uses digital pulse technology to transmit and relay warning messages for weather hazards such as tornadoes, severe thunderstorms, flash floods, and hurricanes.

These pulses are digital codes which contain information that activates specifically designed EAS and NOAA Weather Radio receivers, based on locality or localities warned for, and the type of warning issued. The three pulses of data after each NOAA Weather Radio tone alert are the end of message codes which deactivate EAS and specially equipped NOAA Weather Radio receivers.

While older NOAA Weather Radio receivers do not utilize the SAME technology, they will continue to activate via the 1050 Hz tone, which will precede all National Weather Service warning messages. SAME will be the primary activator for the new Emergency Alert System (EAS) planned by the Federal Communication Commission.

NOAA Weather radio currently broadcasts from 400 FM transmitters on seven frequencies in the VHF band, ranging from 162.400 to 162.550 megahertz (MHZ) in fifty states, Puerto Rico, the Virgin Islands, Guam, and Saipan. These frequencies are outside of the normal AM or FM broadcast bands.

Special radios that receive only NOAA Weather Radio, both with and without special alerting features, are available from several manufacturers. In addition, other manufacturers are including NOAA Weather Radio as special features on an increasing variety of receivers. NOAA Weather Radio capability is currently available on some automobile, aircraft, marine, citizen band, and standard AM/FM radios, as well as communications receivers, transceivers, scanners, and cable TV.

By Nature and design, NOAA Weather Radio coverage is usually limited to an area within 40 miles of the transmitter. The quality of what is heard is dictated by the distance from the transmitter, local terrain, and the quality and location of the receiver. In general, those on flat terrain or at sea, using a high quality receiver, can expect reliable reception far beyond 40 miles. People living in cities surrounded by large buildings and those in mountain valleys with standard receivers may experience little or no reception at considerably less than 40 miles. If possible, a receiver should be tested in the location where it will be used prior to purchase.

NOAA Weather Radio is directly available to approximately 70 to 80 percent of the U.S. population. The National Weather Service is currently engaged in a program to increase coverage to 95 percent of the population.

The Voice of the National Weather Service broadcasting continuous weather information 24 hours a day, 7 days a week.

Click TRANSMITTERS AND FREQUENCIES for a list of NOAA Weather Radio sites that are broadcasting throughout the United States.

Your inquiries and comments are greatly appreciated. If you have a question regarding the weather information broadcast over NOAA Weather Radio, please send your e-mail to the Billings National Weather Service Office .