Uniden UBCD436-PT Owner's Manual page 85

All FIPS - The scanner sounds a weather alert siren for any county.
The scanner displays warning level as "Warning WX," "Watch WX" or "Advisory WX" and it
displays decoded Event Code.
When an alert is received, press any key to listen to the alert.
The scanner will mute and scan only the weather channels.
WARNING! If you receive an alert it will be at FULL volume.
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