About this page
Sources of weather actuals.
WARNING!
Noting the great improvements in weather prediction over recent years and the way in which National Weather Service NWP models use all available data - it is debatable whether much use can be made by a sailor of weather actuals, see my page on DIY forecasting A personal, some would say cynical, view is that they are a comfort blanket! Perhaps they are most useful as an aid to monitoring the forecast. Is that front on schedule?
When at sea, the Coast Guard can always be called up on marine VHF. They should have immediate access to the Met Office page of marine weather actuals.. Many coastguard stations no longer have a view over the sea.
Related pages
- "Official" weather sites around NW Europe
- "Unofficial" weather sites around the British isles
- "Unofficial" weather observations worldwide
- Single Observer forecasting
- Measuring visibility
- Observing Wind at sea
- Pressure units.
On this page -
Observing networks
Weather observations are made for a variety of reasons. Civil and military airfields need a continuous supply of reliable data. Weather services need data for day to day forecasting and climatological purposes. Weather monitoring is necessary for offshore exploration and routine purposes. National weather services usually co-ordinate all these observing systems and this includes monitoring of sites, checking instrument siting and observing practice, collection and quality assurance of the data. Observing Is increasingly automated. While this reduces error on instrumental readings, it limits the amount of descriptive information available, such as cloud type and description of weather.
Because of the general interest in weather there are many more observing sites using various types of instrument. Mostly, these are fully automatic sites with no monitoring in real time.
In terms of reliability, observations from ”Official" sources will be more reliable than from "Unofficial" sites.
BBC Radio 4 Shipping Forecast
After the late-night shipping forecast on Radio 4 LW, 198 kHz, there are about 25 reports from locations around British Isles coasts starting from Tiree. After the early morning forecast there are about 12 station reports. The lists do change slightly from time to time as observing locations change. Some stations are manned; others are automatic stations. At the latter there are, currently, no reports of "weather" ie rain, snow etc.
For a nice little read, see Weather Reports from Coastal Stations by Geoff Saunders.
Because of pressures on time available in the BBC schedules and the importance given to the shipping forecasts over and above the actuals, it is very unlikely that the BBC will give more air time for this purpose during the daytime.
NAVTEX 490 kHz
Around the UK, the national NAVTEX service on 490 kHz provides actual reports. For schedules see the NAVTEX page or the MCA- 064 Marine Safety Leaflet (a 1.4 Mb PDF).
"Unofficial" Automatic Weather Stations eg CHIMET
There are some automatic weather stations sites at strategic locations such as the Chichester Bar (CHIMET) and on the Bramble Bank, at the entrance to Southampton water. These stations report wind and sea state among other parameters. Just how useful these are to the leisure sailor is a matter of personal opinion. Clearly, it must be useful to the master of a large bulk carrier coming up the Solent to know what the wind is like over the Bramble Bank..
On a slow moving yacht two or three hours off the Chichester Bar, I would be paying more attention to the tide tables and working out the state of tide over the bar for my ETA. A report of sea state two or three hours before ETA would not necessarily be relevant
In the event of a strong wind, I would be aiming to arrive with the most favourable tide/wind conditions. A knowledge of wave and wind some few hours off would not help very much. I would be well aware of the wind strength and direction. I would have heard the forecast. In such situations conditions will depend greatly on the time in the tidal cycle. Information of such sort may well not be a good indicator of future conditions even a short time ahead.
Such data are no doubt interesting, but there is no substitute for good seamanship and careful planning. I have given a Listing of "Unofficial" weather sites" around the British isles on another page
Summary
From the above, it can be seen that the Internet is a good source of latest actual data when ashore, in harbour or within mobile phone range of the coast. At sea, the options are the BBC late at night and early morning, NAVTEX 490 kHz and, if really necessary, the Coastguard on VHF.