New York VOLMET: North American airport weather on 6604 kHz

What you hear

A synthesized voice reads airport observations in the familiar VOLMET rhythm, airport after airport, but with an American accent in the details: the pressure comes as "altimeter two niner niner two", in inches of mercury rather than a QNH in hectopascals, and the visibility is in statute miles, so "visibility one zero" means ten miles. The airports are the big ones of the eastern half of the continent: New York's three, Boston, Washington, Atlanta, Chicago, Detroit, Miami and others, with Bermuda in the list for the crossing.

Listen for a while and you notice that the frequency is not New York's alone. For twenty minutes after the hour and after the half hour the voice is New York's; then the broadcast passes to Gander, in Newfoundland, which reads Canadian airports for ten minutes, and then New York returns. Two VOLMETs on one set of frequencies, sharing by the clock. If you tune in during the Gander segment you hear Halifax, Montreal, Toronto, Ottawa and Gander itself.

Who transmits and why

The broadcast is part of the North Atlantic VOLMET service agreed through ICAO: Shannon, Gander and New York divide the airports between them and keep weather on the air continuously for crews crossing the ocean. The New York share is transmitted by the New York aeronautical radio station, the same service that handles HF voice contact with aircraft in the New York oceanic area. The reports are METARs, refreshed as the airports issue new ones, which in North America is every hour.

Why keep a voice broadcast in the age of datalink: because HF needs nothing on the aircraft beyond the radio that is already there for oceanic contact, and because a loop that repeats every half hour is the simplest way to put the same numbers in front of hundreds of aircraft at once.

When and where to listen

The service uses 3485, 6604, 10051 and 13270 kHz in upper sideband. 6604 kHz is the workhorse of the evening and night on the American side, and the frequency to try from Europe: after dark on the western side of the Atlantic, which is late evening and night in Europe, 6604 kHz crosses the ocean and is heard on receivers in Ireland, Britain and western Europe, weak but readable, strongest towards European dawn. Receivers on the east coast of the United States and in eastern Canada hear it loudly at any hour. In daylight the lower frequencies fade and 10051 kHz, listed separately in the catalogue, carries the service.

The synthesized voice is a little clipped; if you miss a number, wait for the next pass of the loop, it comes round within half an hour.

In ShackDeck

Station catalogue → Aviation → New York VOLMET. The program picks a public receiver that covers 6604 kHz, tunes it and sets USB; you need no receiver, antenna or account of your own. The daytime row, New York VOLMET 10051, is the one to choose when 6604 kHz is silent.