Inshore waters vs BBC coastal forecast

[NickNap]

I've noticed that the BBC coastal forecast for my area (Lyme bay) is often quite different (usually lower wind speeds) than the inshore waters version. I understand the BBC one comes from the Met office; which should I take as most appropriate for coast hopping - or should I average them out?

 

[Sgeir]

Interesting comment, as I have also noted some apparently contradictory forecasts recently in the Caledonian (Oban) and Minch areas. For instance, while sailing recently (no internet access) we have noticed dire warnings of strong winds or gales on the Shipping Forecast, but only 4/5 on the Inshore Waters Forecast. I presume that the more precise geographic definition of the Inshore Forecast (up to 12 miles offshore) accounts for this.

If I was in Barra right now, the Inshore Forecast (from 1700 tonight)warns <ul type="square"> Wind: variable 3 or 4 becoming cyclonic then west 4 or 5, increasing 6 for a time near Barra, and for the following 24 hours, west or southwest 4 or 5. [/list]
Meanwhile the Shipping Forecast, older, issued 1130 this morning, mentions <ul type="square"> VARIABLE BECOMING SOUTHEAST 3 OR 4, VEERING SOUTHWEST 4 OR 5 LATER IN SOUTHWEST - no mention of a 6. [/list]
However, no need for a reef because the BBC says that Castlebay (Barra) will be 16 mph (ie F4) SE today, and 9 mph (ie F3) NW tomorrow.

Maybe they are/were all "correct" when issued, and vary because of computed differences in land/sea speeds, and taking account of the Beaufort scale being measured 10m above ground/sea level etc.

But I agree, it can be confusing. I tend to play safe, and go by the CG broadcasts of the Inshore F/C, but listen also for the Shipping Forecast and, more interestingly IMO, the reports from coastal stations.

 

[gandy]

Which is more accurate, for you?

 

[thalassa]

We went from Belgium to Devon and back during four weeks in June and July this year, and became very desillusioned with the BBC Inshore forecast. I've even kept some of the printouts as a souvenir. The forecast i.e. would be NW force 3 for Brighton, five days in a row. This, while everyone, including the fishermen, kept to their moorings while the 7 Bft blew incessantly for three days from the SW.
Will.

 

[NickNap]

Tony
Are you in adult education by any chance?

 

[JKay]

just use the one that is best for you /forums/images/graemlins/cool.gif

cheers Joe

 

[claymore]

Thats very good advice.. We often go with the Clyde Inshore waters forecast as its oftem much sunnier than the Caledonia or Minch ones, it tends to rain less and the winds are often a strength or two lighter - except in the north Channel but as we are not there anyway this doesn't affect us.
Hope that helps

 

[bluedragon]

I've been very disillusioned with forecasts over the past month. We were in Milford Haven waiting for a decent 2-3 days slot to have an enjoyable end of cruise sail back to Cardiff via. Tenby and the Gower anchorages. I spent probably an hour or so each day trying to make sense of it all. Firstly, the weather pattern we've had has I believe given the forecasters a hard time, and most of the so-called general weather forecasts from the BBC or local radio, or freely available on the internet have been rubbish as far as sailors were concerned in my part of the world. What worked best for me was a) the shipping forecast to get the big picture b) inshore waters forecast for the next 24 hours (but NOT the following 24 hrs or the 3-day outlook) c) Windguru's MM5 subscription model (not the free GFS stuff...always 1 or 2 Beaufort low...but useful for a longer term 7-day outlook). I see the Met Office are "improving" the inshore waters forecast from Sep.4th...I await with interest!

PS - just looked at the BBC coastal forecast for my area for this evening. It says:
Wind speed - F3-5 becoming F2-5
Wind direction - W
Max gust in knots - 32 becoming 26

Now I ask you, what is a small boat owner to make of that!! F2...great...F5...hmmm? Max gust 32 kn...No way!!
Waste of time IMHO.
Met office inshore waters says W4-5. Sitting here in Cardiff Bay and looking at actual observations out west, that seems about right.

 

[jonathankent]

I once looked at all the different weather sites available hoping that my checking most I would be able to see the general prediction. Out of all the sites I looked at they all seemed to say the same thing, execpt for the Met Office's inshore waters forecast.... so, I thought that the Met Office must have made a mistake - far from it, they were in actual fact the only ones that got it right, so taught me a lesson.

When it comes to weather/wind for sailing, I tend to find the Met Office's inshore forecast will generally predict a higher wind speed than any of the shorebased weather predictions, i.e. for my area I get RNAS Culdrose's weather station data and forecast, but they are never the same as the Met Office and tend to be lower wind speed. I suppose there is a difference between the way the wind behaves on land as supposed to across the sea. I must read my weather book again and get clued up, then just look at the synoptic charts myself.

 

[Dipper]

I may be wrong but the only reason for the difference that I can think of is that the Met Office have to give the worse case scenario for each forecast. Inshore, the worse case would be a prolonged gust off a headland eg Portland Bill. Further out, there are no headlands to force an increase in wind speed. Headlands can quite easily result in a local increase of one Beaufort scale unit and very occasionally more.