Sea State

[NormanS]

Am I the only person who feels that the "Sea State" given on both the Shipping Forecast, and the Inshore Forecast, is an insult to my intelligence?

Today, for example, we are told that the wind will be 5 to 7, perhaps 8, and that the sea state will be slight in shelter, otherwise moderate or rough.

Well, obviously it will be smooth or slight in shelter. That's what shelter means. Outwith shelter, if the wind is going to be 5-7, perhaps 8, then obviously it will be a bit rough. Surely I can work that out for myself, and not have some nanny sitting in an office telling me.

The actual local sea state depends on so many variables, that a forecast for a whole sea area, particularly in the Inshore Forecast is a nonsense. One has to consider depth, fetch, proximity to exposed headland, and direction of tide etc, as well as the strength of the wind.

On a practical level, the Navtex transmission from Portpatrick, which covers the West Coast of the UK, often runs out of time or space, and so misses out the forecast for some of the northern areas. If it didn't rabbit on about "slight in shelter etc", there would be plenty of time / space, and we would get the whole forecast.

Rant over.

 

[Csail]

We go out in almost anything, Swansea coastguard (who overlook Swansea bay) said sea state slight, it was massive so we turned back. Do they not look out of the window?

 

[chanelyacht]

We go out in almost anything, Swansea coastguard (who overlook Swansea bay) said sea state slight, it was massive so we turned back. Do they not look out of the window?

No. MRCC's aren't allowed to.

The days of adding "actuals" at the end of the weather are long gone - and not always relevant. I could say what I see from my window, but I know that would be irrelevant a mile away in either direction, as further up the estuary would be half what I see, and out beyond the heads would be treble!

Agree Swansea are in a better position vantage wise.

I don't think the forecast sea states are irrelevant, but like any forecast they need interpreting - wind over tide changes this considerably, which the forecasts don't take into account for anything other than a large geographic area.

Not perfect, and I'd love to be able to give out actuals, but also don't forget a long weather broadcast also takes Ch67 aerials away from us for that length of time, which is why if we're running a large(ish) job we'll often dump the weather.

 

[chanelyacht]

On a practical level, the Navtex transmission from Portpatrick, which covers the West Coast of the UK, often runs out of time or space, and so misses out the forecast for some of the northern areas. If it didn't rabbit on about "slight in shelter etc", there would be plenty of time / space, and we would get the whole forecast.

Rant over.

Not a rant, useful info. Have you raised it with Falmouth, feedback like that is taken seriously.

 

[Csail]

No. MRCC's aren't allowed to.

The days of adding "actuals" at the end of the weather are long gone - and not always relevant. I could say what I see from my window, but I know that would be irrelevant a mile away in either direction, as further up the estuary would be half what I see, and out beyond the heads would be treble!

Agree Swansea are in a better position vantage wise.

I don't think the forecast sea states are irrelevant, but like any forecast they need interpreting - wind over tide changes this considerably, which the forecasts don't take into account for anything other than a large geographic area.

Not perfect, and I'd love to be able to give out actuals, but also don't forget a long weather broadcast also takes Ch67 aerials away from us for that length of time, which is why if we're running a large(ish) job we'll often dump the weather.

Totally agree but our boat is decently equiped but on that occasion the sea state was not smooth.....more like 2m breaking waves.

 

[awol]

I wish the correlation between local wind and sea state was that simple. Gales elsewhere can have a profound effect and I appreciate the inclusion of sea state especially for unsheltered waters.

As for Portpatrick - tune your Navtex to Malin Head instead!

 

[Robin]

.

Not perfect, and I'd love to be able to give out actuals, but also don't forget a long weather broadcast also takes Ch67 aerials away from us for that length of time, which is why if we're running a large(ish) job we'll often dump the weather.

If there is no guaranteed broadcast then in effect there is no forecast because you simply cannot rely on it. Might as well just stop the forecasts and allow more time for radio checks.

 

[chanelyacht]

For local conditions, the NCI are handy if they've a station operating near you. (www.nci.org.uk)

 

[Barnacle Bill]

My problem is when the CG don't read out the 'what'.

For example you might get:

"Hebrides - South west 3 or 4 - moderate - fair - moderate"

How confusing can that be for a visiting yachtsman?

 

[TonyS]

We find the web sites are better. Passage weather and magic seaweed are good. The other two sites we bookmark are the two channel light vessels. These give the wave height and swell forecast for days in advance. We bookmark them with meteo consult on our kindle 3G and can get wave and wind forecasts within 30 miles of the coast of UK or France for free. The channel light vessels, 62103 and 62305, are excellent for knowing what is actually happening, wind, swell etc with history, to the west or east when crossing the channel as are Bramblemet and chimet in the Solent.

 

[NormanS]

I wish the correlation between local wind and sea state was that simple. Gales elsewhere can have a profound effect and I appreciate the inclusion of sea state especially for unsheltered waters.

As for Portpatrick - tune your Navtex to Malin Head instead!

You are perfectly correct. Malin Head now gives an excellent Navtex service, and when it was pointed out to the MCA that MH were not doing Ardnamurchan to Cape Wrath, they were asked to do it, and now do. Interestingly, just at the time that Malin Head started to do their Navtex transmissions, the gremlins that had been endemic at Portpatrick, mysteriously disappeared, and it now gives a good service. It would still be better to get the forecast from both stations, as they come in at different times.

 

[NormanS]

Not a rant, useful info. Have you raised it with Falmouth, feedback like that is taken seriously.

Thanks, but it took so much time and effort to get Portpatrick improved and augmented by the transmissions from Malin Head, that I don't want to get involved again.

 

[franksingleton]

Weather actuals, updated hourly are available at http://www.metoffice.gov.uk/weather/marine/observations/ from most of the “official” reporting sites around our coasts. There are Irish data buoy reports at http://www.met.ie/latest/buoy.asp. You may find more reports at http://www.ndbc.noaa.gov/maps/France.shtml and http://www.ndbc.noaa.gov/maps/United_Kingdom.shtml.

I am never too sure how really useful are sea state forecasts. Given the wind force, knowledge of tidal stream and location, sea state should be fairly obvious. What is not obvious is the swell. A shortcoming of UK forecasts is the lack of swell information. Forecasting swell is fairly straightforward. Météo France give sea state (I assume wind-sea) and swell separately.

I am not at all sure whether the forecasts of sea state are a combination of swell and wind sea or just wind sea. I will try to find out.

 

[franksingleton]

My problem is when the CG don't read out the 'what'.

For example you might get:

"Hebrides - South west 3 or 4 - moderate - fair - moderate"

How confusing can that be for a visiting yachtsman?

The shipping forecast, 26 areas and about 1M sq miles, has to be written in 330 words maximum to fit in the BBC's allocated 3 minutes. Redundant words have to be omitted.

Taken in isolation your example is ambiguopus. Taken in the context of other areas saying eg

"Malin - Variable 3 or 4 3 or 4 - slight - fair - moderate", it is understandable.

 

[NormanS]

The shipping forecast, 26 areas and about 1M sq miles, has to be written in 330 words maximum to fit in the BBC's allocated 3 minutes. Redundant words have to be omitted.
.

Like "Smooth or slight in shelter"

 

[franksingleton]

Like "Smooth or slight in shelter"

Yes, but my statement referred to the BBC shipping forecast. Those words were clearly unnecessary on a VHF broadcast and I would rank them as silly. Brevity is a requirement on VHF in order to keep forecasts to the tight schedule.

 

[franksingleton]

Am .......................
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On a practical level, the Navtex transmission from Portpatrick, which covers the West Coast of the UK, often runs out of time or space, and so misses out the forecast for some of the northern areas. If it didn't rabbit on about "slight in shelter etc", there would be plenty of time / space, and we would get the whole forecast.

Rant over.

On NAVTEX, the priority items are NAV warnings, Gale warnings, Ice warnings, Distress messages ie messages types A, B, C, D. Weather forecasts, E are not priority. If the warnings fill the 10 minute slot then forecasts can be cut.

But, by all means, as has been suggested, contact Falmouth if it is a frequent occurrence.

 

[agurney]

Like "Smooth or slight in shelter"

The sea state isn't always smooth or slight when sheltered from the wind.

 

[NormanS]

The sea state isn't always smooth or slight when sheltered from the wind.

So what do they mean then?

 

[Twister_Ken]

What is not obvious is the swell. A shortcoming of UK forecasts is the lack of swell information. Forecasting swell is fairly straightforward. Météo France give sea state (I assume wind-sea) and swell separately.

As does, as I recall, Jersey Radio.