Perhaps this has to do with the powerful high pressure blocking over the Atlantic and resulting northerlies bringing cold air and moisture from over the North Sea. But I'm not a meteorologian (or meteorologician?)

Maybe even the the Gulfstream figures into this. Do note that we are in the negative NAO index.

Satellite photo taken yesterday, Thursday 07.I.10

Thank you to kW and gP! And belatedly to sW!