Whirlybird's link is good, but too slow for my lousy dial up at home, and doesn't make it through the firewall at work, so my list is:
Of course the Met Office, both the aviation pages and this one:
http://www.metoffice.gov.uk/weather/charts/index.html
And I look at this site using the "Mittl. Wolken" predictions (with cloud for you and I):
http://www.wetterzentrale.de/topkarten/fsavneur.html
I'll see if IO540's link is useful in the long term, thanks for that.
Cheers
Rich