USCG HF SITOR

National Weather Service Marine Forecasts

U.S. COAST GUARD HF SITOR

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NATIONAL WEATHER SERVICE MARINE PRODUCTS VIA U.S. COAST GUARD HF SITOR

USCG to continue HF weather broadcasts via radiofax, voice, and SITOR

The U.S. Coast Guard broadcasts National Weather Service highseas forecasts and storm warnings from four high seas communication stations in the SITOR mode . These broadcasts are prepared cooperatively by the Ocean Prediction Center, National Hurricane Center and Honolulu Forecast Office. Offshore and coastal forecasts are available in areas such as Alaska. The International Ice Patrol also broadcasts from Boston sharing the same transmitters. See table below for station locations and schedules. Transmission range is dependent upon operating frequency, time of day and atmospheric conditions and can vary from only short distances to several thousand miles. Best reception can be achieved by proper selection of frequency and an adequate antenna system. Visit the U.S. Coast Guard Maritime Telecommunications Information webpage for further information on U.S. Coast Guard telecommunications.

Click here to listen to what a typical SITOR signal sounds like on the air.

U.S. Coast Guard SITOR (SImplex Teletype Over Radio) text broadcasts are performed in mode B, FEC. SITOR is also known as Narrow Band Direct Printing (NBDP). SITOR/NBDP is an automated direct printing service similar to NAVTEX, but does not offer all of the same functionality such as avoiding repeated messages.

Refer to NGA Publication 117, which is updated through the Notice to Mariners, for the latest official listing of U.S. Coast Guard broadcast schedules. The British Admiralty List of Radio Signals , is an excellent reference source for weather broadcast information.

All NWS marine forecasts rely heavily on the Voluntary Observing Ship (VOS) program for obtaining meteorological observations.

Boston(NMF)
HF SITOR (NBDP) Broadcast Schedule

6314, 8416.5, 12579 kHz 0140Z³

8416.5, 12579, 16806.5 kHz 1630Z³

³Includes ice from International Ice Patrol

Pt. Reyes(NMC)
HF SITOR (NBDP) Broadcast Schedule

8416.5, 16806.5 kHz 0015Z 1730Z

Honolulu(NMO)
HF SITOR (NBDP) Broadcast Schedule

8416.5, 12579, 22376 kHz 0130Z 2030Z

8416.5, 12579 kHz 0730Z 1330Z

Guam(NRV)
HF SITOR (NBDP) Broadcast Schedule

12579, 16806.5, 22376 kHz 0230Z¹ 0500Z 0900Z¹ 1500Z 1900Z 2315Z

¹HYDROPAC navigation message, no weather

Assigned frequencies shown, for carrier frequencies subtract 1.7 kHz. Typically specialized marine communications equipment uses assigned SITOR frequencies while general purpose equipment uses carrier frequencies. Note that stations share common frequencies.