looks unpleasent, i assume we all know but i will post anyway!
Westherfil.com has a great list of live and historic weather - they have devices at mudeford, parkstone YC and portland outer harbour (plus loads more but these i use).
Great to see what it is actually like before setting off from home. esp if wind was supposed to drop off overnight and you are expecting less swell etc - this is where the history comes in to it's own.
REMEBER TO CHANGE SETTINGS FROM m\s to knts!