Weatherfax Maps by Radio

There are people who fax weather maps via radio. You probably don't even have a fax anymore. Who faxes anymore? Apparently the answer to that rhetorical question is the coast guard. There is a coast guard station on shortwave radio station from Boston that faxes weather maps to ships at sea. The call letters are NMF.
For this strange practice we can actually thank Prohibition. Prior to prohibition, the Coast Guard (USCG) had more-or-less the same radio equipment as the navy: marine telegraph.. just Morse code.

So in 1924, about 3 years after crime surged, there was a response from the Coast Guard. They opened shore radio stations at a dozen ports: Fort Tilden, NY, Nahant, MA; New London, CT; Cape May, NJ; Cape Henry, VA; Fernandina, FL; Fort Lauderdale, FL; Mobile, AL; San Francisco CA; San Pedro, CA; Port Angeles, WA; and Anacortes, WA. All of this was to help handle all the communications from all of their new ships. More here.

This was all deployed in about 5 years; a very short period of time. The base on New London signed on in 1924 with the calls NLO. That station in Nahant signed on in 1926 with the calls NCP. In 1931 that station in Nahant was moved and reestablished at Fort Heath, Winthrop, MA. It's new calls were NMF. It was closed from 1934 - 1936 then reestablished, again. Then in 1939, the site was taken over by the U.S. Army. The Cost Guard radio equipment was relocated to North Truro, MA. The NMF calls reappeared on a base in Marshfield, MA. This continued at least 1942 - 1972.  In 1975 it relocated to Otis Air National Guard Base on Cape Cod.  By then the station was processing over 30,000 radio messages per month. More here. NMF was decommissioned in November 18th, 1996. It's last broadcast words were as follows:

"Camslant Chesapeake this is commsta Boston, transferring communications watch at this time, over. Camslant's reply: "Roger, we have the watch, thank you for you dedicated service throughout the years - out."

The NMF calls are still used by NMN Chesapeake, VA when sending Boston Weatherfax. Some marine Radio texts, such as Reed's Nautical Almanac even note those calls for that purpose. NMG in New Orleans delivers similar maps by radio fax for the Gulf region. You can see the NOAA weather maps here.