Is this a weather window or a trapdoor?

We've my Shetland family staying in Fortrose for the w/e, and they're very concerned about the Monday night ferry, even that it might not sail.
In your situation, where you've no time pressure (I believe), berthed in a decent place with good food/drink abounding, prudence is a better feeling than an ongoing feeling at sea of "Are we going to get away with this?".
As you stated, it's meant to be fun.(y)🥃
 
Forget this, “I use Windfinder, Ventusky etc.” stick to ECMWF, GFS as your prime advisers., however you get them. We are using ECMWF and GFS both through Sailmail. I open with PocketGrib so know which data time they are based on. ECMWF and GFS give you longer period forecasts than others. Look for consistency in output from one run to the next. When you have that, then models will be broadly similar to each other. If there are significant differences between models, trust none. An outlier might be best on the day.
Remember that all models contain smoothing. Winds will, at times be at least one force higher than
predicted.
Using forecasts in such an extreme, indeed any situation, ask yourself what would, say, a 10 % increase in speed of movement of the low.
 
The validation feature in Predict Wind is useful for showing which Model has been the most accurate over a period of time, compared to actual.

The validation explanation in the help files needs to be read to understand what is being shown. Also the validation is based on local station reports surrounding your area of interest (shown on the map).

For my sailing area, south of Oban ECMF is fairly consistent at the top of the table. So far, GFS has not been, it’s at the bottom.

I find validation useful in selecting a forecast to go with, as well as the grouping of similar data from the different tables.
 
The validation feature in Predict Wind is useful for showing which Model has been the most accurate over a period of time, compared to actual.

The validation explanation in the help files needs to be read to understand what is being shown. Also the validation is based on local station reports surrounding your area of interest (shown on the map).

For my sailing area, south of Oban ECMF is fairly consistent at the top of the table. So far, GFS has not been, it’s at the bottom.

I find validation useful in selecting a forecast to go with, as well as the grouping of similar data from the different tables.
There is something in what you say. WMO verities predicted surface pressure by using RMSE. Consistently, ECMWF, UK global, DWD, Merio France are all very similar out to about 6 days. GFS is not so good. On the other hand, and we have been cruising France from Lezardrieux to Ile d’Oleron since early May, there have been no significant differences in the guidance. Just recently, we had a spell of morning NE winds becoming NW and increasing,both GFS and ECMWF,predicted a change to early N winds becoming W. That made a great difference to our decision making for the passage Pontic to Piriac sur Mer.
WMO does not verify using surface wind reports. Choice of stations used would always be questionable. Near land, local effects would dominate. Also, surface wind even over the sea is naturally variable.

PS, After late re-reading, correction in bold.
 
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Well, the 48 hour window from today is holding, all models, but heyho the die is now cast snd we remain in Lerwick. Lovely sunny day touring in the rentawreck today

The next window, from Wednesday, has disappeared with every day next week now featuring gusts in the mid to high thirties, from varying directions.

- W
 
More post-non-departure analysis suggests that had we left yesterday we would have had to motor almost all the way across to arrive before Floris, as the flat calm area tracked/tracks our necessary 5-knot progress.

Now it looks as though we will be here for at least another week as a series of post-Floris lows track across.

.i fear harbour rot may be setting in.

- W
 
More post-non-departure analysis suggests that had we left yesterday we would have had to motor almost all the way across to arrive before Floris, as the flat calm area tracked/tracks our necessary 5-knot progress.

Now it looks as though we will be here for at least another week as a series of post-Floris lows track across.

.i fear harbour rot may be setting in.

- W
Is the harbour safe, or are you bouncing about? Are you on a berth where you can easily walk ashore, or is it a dinghy ride?
 
Seek the "expert" opinion on the YBW forum then do what you were going to do anyway.
Sensible advice. The safety of boat and crew are the inescapable responsibility, solely, of the skipper. When it comes to weather, as with navigation it is necessary to have some understanding about the data and how to use them. There has long been some mystique about weather that, in some minds, clearly still exists. As a former professional meteorologist and a long time sailor, over 60,000 cruising miles, I try to inject a little common sense into discussions about forecasting. It is a matter of personal choice what, in the event, anyone does with forecasts.
 
Once stuck in Plockton for 3 days on a mooring. Three old blokes on a 36' boat , way too rough for flubber trips ashore. Not pleasant. One of us teetotal......not me fortunately.
 
It's safe, a great berth, snug and within 5 minutes walk of pretty much everything. As places to get stuck go its pretty good.
I'm not as nerdy about which selection of computer-model guesses to favour.... Not quite.
But they all seem to suggest Monday may not be a good day to be at sea/Norwegian Sea/Moray Firth in ANY boat.

venti.JPG

It's worth noting that most of them are now indicating even deeper 'Deepening' than previously.

Time to reef the geraniums and borrow big fenders!

;)
 
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