Over the middle of the North Atlantic, aircraft are beyond the range of VHF radio. To get weather for their destination, pilots tune a shortwave broadcast called a VOLMET (from the French vol, flight, and météo, weather). The best known is broadcast from Shannon in Ireland.
Frequencies
Shannon VOLMET uses upper sideband (USB) on four frequencies, so pilots can pick whichever is coming through:
- 3413 kHz
- 5505 kHz
- 8957 kHz
- 13264 kHz
Which one works best follows the usual shortwave pattern: lower frequencies at night, higher by day. 5505 kHz is a good first try.
What you’ll hear
A synthesised voice reads the current conditions and forecasts for a list of major airports: wind, visibility, cloud, temperature, dew point and pressure, in the standard order pilots expect. VOLMET broadcasts run on a fixed timetable of five-minute slots that repeats every hour, and other stations, such as Gander in Canada and New York, have slots of their own.
Why listen?
It’s strangely calming, and it’s live: these are the reports pilots over the ocean are listening to right now. It’s also an excellent propagation check from North America or Europe, because it never stops.
Tune it
Skywave DX lists Shannon VOLMET under Signals and tunes it through a public receiver that can hear it. Upper sideband sounds right only when tuned exactly, so let the app set the mode for you. Other aviation listening: the 121.5 MHz guard frequency page explains the VHF emergency channel.