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
.