About this page.
RadioFax broadcasts are still a valuable source of weather information.
Preamble
This page may remind those who vaguely remember the long lamented Bracknell GFA broadcast. Following the discontinuation of GFA, the Royal Navy enhanced its transmissions from Northwood - GYA. This page lists the Marine content of the Northwood schedule and adds some comments. There are pages on history and a summary of the need for Radio Fax elsewhere on this site A separate page deals with reception problems.
On this page -
RadioFax Reception'
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There are some dedicated equipments available but, usually, most people use a standard HF/SSB receiver and a laptop. The NASA HF3 is a very cheap set that does a good enough job for most needs although it may need more careful |
tuning than more expensive sets, As the future is in some doubt, it may be the most sensible buy. For software, there are several packages around such as Mscan or JVcomm. |
Northwood Radio Fax - GYA
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To many sailors, this broadcast is probably more useful than either the old Bracknell GFA or the old RN Northwood GYA broadcasts. There is emphasis on forecast information in wind vector form rather as well as isobars. There are two significant improvements over the Bracknell broadcast -. First, forecast charts now have wind vectors for winds of 25 kn or more. These will appear as shown here for SW 20 and N 25 knots. |
Secondly, the chart headings are difficult to read. It will be necessary to refer to the schedule to know what chart is being received. Third, because much of the output is computer generated, the lines tend to be rather thin and not so easy to see as the "old" Bracknell charts. As already emphasised, users should remember that this is a broadcast explicitly for RN and NATO ships. It has information on it that is clearly of a military nature and much information not at all relevant to yachtsmen and women. To reproduce the GFA footprint, it would have been necessary to use the whole range of Bracknell frequencies. GFA, Bracknell, used to use frequencies up to 14,436 kHz H24 and 18,261 kHz by day. The highest frequency now used by Northwood is 11086.5 KHZ. This limits the day time range for good reception by yachts that are unlikely to have optimum aerial configurations. However, an old friend - George Lipscombe - found good reception on a passage from the UK to the Azores. The big uncertainty, of course, is how long the Navy will continue with this broadcast. presumably, it is essentially a back up to more modern methods of chart dissemination. the pressure must still be on for the long distance sailor and those likely to be out of normal land line telephone contact to keep abreast of technical developments in the field of satellite communications. |
NOTE - The schedule below is of those transmissions likely to be of use to leisure and professional sailors. Some transmissions are for the use of Naval aircraft and submarines but of no interest to the sailor.
NORTHWOOD Schedule
Area__: North Atlantic and Mediterranean
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Frequencies | |
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2618.5 kHz |
HH+24 |
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4610 kHz |
HH+24 |
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8040 kHz |
HH+24 |
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11086.5 kHz |
HH+24 |
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Broadcast time* |
Chart |
Data time* on which product is based |
|
0000/1200 |
Surface (MSLP) analysis (Repeat) |
1800/0600 |
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0012/1212 |
Surface (MSLP) prognosis T+24 (Repeat) |
1800/0600 |
|
0100/1300 |
Schedule | |
|
0236/1436 |
Surface (MSLP) analysis |
0000/1200 |
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0300/1500 |
Surface (MSLP) analysis (Repeat) |
0000/1200 |
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0336/1536 |
Sea surface temperature (SST) | |
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0348/1548 |
Gale Warning summary | |
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0400/1600 |
Surface analysis (Repeat) |
0000/1200 |
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0436/1636 |
Surface (MSLP) prognosis T+24 |
0000/1200 |
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0500/1700 |
Surface (MSLP) analysis (Repeat) |
0000/1200 |
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0512/1712 |
Surface (MSLP) prognosis (MSLP) T+24 (Repeat) |
0000/1200 |
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0524/1724 |
Surface (MSLP) prognosis T+48 |
0000/1200 |
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0548/1748 |
Gale Warning Summary | |
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0600/1800 |
Surface (MSLP) analysis (Repeat) |
0000/1200 |
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0612/1812 |
Surface (MSLP) prognosis T+24 (Repeat) |
0000/1200 |
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0724/1924 |
Surface (MSLP) prognosis T+48 |
0000/1200 |
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0736/1936 |
Surface (MSLP) prognosis T+72 |
0000/1200 |
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0748/1948 |
Surface (MSLP) prognosis T+96 |
0000/1200 |
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0800/2000 |
Surface (MSLP) prognosis T+120 |
0600/1800 |
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0824/2024 |
Significant surface winds (grid points) prognosis T+48 |
0000/1200 |
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0836/2036 |
Significant surface winds (grid points) prognosis T+72 |
0000/1200 |
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0848/2048 |
Significant surface winds (grid points) prognosis T+96 |
0000/1200 |
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0900/2100 |
Surface (MSLP) analysis |
0600/1800 |
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1000/2200 |
Surface analysis (Repeat) |
0600/1800 |
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1012/2210 |
Surface (MSLP) prognosis T+24 |
0600/1800 |
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1024/2224 |
Reduced visibility prognosis T+24 |
0600/1800 |
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1100/2300 |
Surface (MSLP) analysis (Repeat) |
0600/1800 |
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1112/2312 |
Surface prognosis (MSLP) T+24 (Repeat) |
0600/1800 |
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1124/2324 |
Sea and swell prognosis T+24 |
0600/1800 |
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1148/2348 |
Gale Warning Summary |
- All times are UTC/GMT Martin Stubbs' site has a link to the most recent version of the FULL schedule.
DWD Radio Fax
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The Deutscher Wetterdienst (DWD) provides a RadioFax service as a contribution to the GMDSS. How long this service will continue is uncertain. The technology is obsolescent and it will probably be replaced by a satellite |
based system within the next 5 - 10 years. Schedules are at the DWD radio-fax broadcast schedules link. |
Worldwwide
Also useful is the NOAA Guide to world-wide radio-fax broadcasts. Although "old tyechnology" radio fax is still a useful service capable of reception over large areas. See my page on HF reception problems.
# # # Secondly, there are forecast charts up to 5 days ahead and available twice a day. There are some unsatisfactory features that may get rectified in time. First, as a power saving measure, the transmitters are switched off between charts. Thus there is no tuning signal prior to the start of a broadcast. This will create difficulties when receiving charts around dawn and dusk since, at these times, the optimum frequency can change quickly due to rapid changes in the characteristics of the ionosphere.
