Emergency alert tones and NOAA Weather Radio (SAME)
A weather alert sounds like three short screeching bursts of data, then a long steady tone, then a voice, and it ends with three shorter bursts. The bursts tell radios what the alert is, where, and for how long.
What does it sound like?
What's in the bursts?
A short digital header called SAME: who sent it (for example the National Weather Service), the event (TOR means Tornado Warning, RWT a Required Weekly Test), the counties it covers as six-digit codes, how long it lasts, and when it was issued. Weather radios read it and sound an alarm only for the counties you've chosen.
Where can I hear it?
NOAA Weather Radio broadcasts on seven channels between 162.400 and 162.550 MHz from more than 1,000 transmitters across the United States. Each transmitter sends a Required Weekly Test.
Why there's no sound on this page
Federal rules forbid transmitting emergency alert codes or tones except in a real emergency or an authorized test (with narrow exceptions, such as some public service announcements). Broadcasters have paid penalties for airing them, and one network faced a proposed $504,000 fine for a clip copied from the internet. So this page shows the picture of the sound instead. Listening to NOAA Weather Radio yourself is perfectly legal; that's what it's for.
Easily confused with
- APRS and packet: short data bursts too, but no long steady tone
- DTMF touch-tones: short two-tone beeps