Preparing for a Day Skipper practical course in Scotland

XC Weather screenshotThe weather

I'm studying the weather forecast for next week's sailing course in the Firth of Clyde.  It will help me to plan where we might go with the wind each day, and which harbours will be sheltered overnight.  We also have to do a 4 hour night sail, which is part of the sylabus.  I prefer a dry night, and not Thursday, as the students will be shattered and have to drive quite a distance home the next day.

I'm using the American GFS forecast on www.xcweather.com because the graphics make it easy to read.  I'm also using the surface pressure charts from www.metoffice.gov.uk so I can compare the forecast from a different computer model.  The Met Office meteorologists look at the computer forecast and modify it, based on their knowledge and experience.  At the moment, it looks like it could be damp most of the week, but Sunday evening may be dry and cloud free.  That's a bonus, I love sailing under the stars.  At sea, you can often see satellites and shooting stars, as well as the Milky Way.

The winds look mostly light to moderate for the week, mainly from North East through to North West from Monday evening onwards.  Hmm, that could mean a cool breeze, I'd better pack an extra fleece jumper.

Surface Pressure ChartThe Met Office surface pressure chart for Wednesday lunchtime shows a low pressure system over North West France, whilst high pressure sits over Iceland.  The isobars between the high & low are squashed tight, bringing stronger winds for most of the UK for a while.

The Met Office doesn't publish charts beyond 5 days, perhaps they don't think the long range forecast is reliable enough.  On the other hand, XC Weather is happy to publish the 8 day forecast it has purchased straight from the GFS computer.  I sometimes wonder which to believe.  I think I'll just prepare for the worst.