OnlineWeather is my regular site. Their verdict...

Forecast is wet on Friday, then sunshine and showers until Wednesday. Then the cloud and rain moves in, and it'll be cloudy the rest of the week. The main thing though is the WIND! No, not a few thousand campers eating beans, but a good breeze most of the way through, and a solid 20-30mph blow around Tuesday/Wednesday. At least the temperature doesn't look too bad, although the wind-chill will suck out most of the warmth.

So if you're camping and you're not too experienced with your tent, make sure you find someone camper than thou (ducky!) who can help you get it pitched solidly. That way you should escape excessive moistness and flysheets living up to their name.

As for what to bring, I'd say plenty of windproof stuff.

Graham.