It's all about the LP at the end of the week, then in the longer term. the chance of a Scandi HP.
FAX - shallow troughs over Britain today, deepening to 993mb off E Scotland tomorrow. LP on Thu 988mb to the SW runs across S Britain to 971mb London early Fri soon moving to the N Sea with wind dying down to a lighter NW-ly Sat.
GFS Op - Thu/Fri LP also 970mb but a little further south, following the Channel, and isobars closer. It loses its identity over SE Europe on Sun while the first signs of a Scandi HP appear 1025mb. The next Atlantic LP makes little progress against the Scandi HP block, at its deepest S of Iceland 955mb Thu 15th, the pressure over Scandinavia rising to 1035mb with strong S-lies for Britain at this stage. The E-ly which seems to be developing Sun 18th fails as the Scandi HP drifts SE-wards to E Russia Tue 13th with Britain left in a shsllow trough linking Iceland and Spain before the Azores HP pokes its nose in Thu 22nd.
ECM - Like GFS to Tue 13th, but then the Atlantic LP doesn't deepen but splits, by Thu 15th part grazing N Norway and part arriving at Brittany 990mb. The second part becomes an extended trough from Greenland - Britain - Holland allowing the Scandi Hp to hold on, just about, but its E-lies haven't reached Britain by Wed 21st.
GEM - somewhere between GFS and ECM to the weekend but the Scandi HP always stays well back over Russia and the Atlantic LP s are further east, so by Wed 14th the whole of W Europe is under S-lies with a small centre of LP over Britain.
AIFS - London 3c to Sun 11th, then up to 10C before dropping slowly to 5C Sat 17th.. Rain Thu into Fri, small amounts therafter. Edinburgh, closer to zero at first, then the rise and fall as for London, rain Sun into Mon, not much earlier.
GEFS - Temps generally cold to Sun 11th (briefly mild Fri 9th), then mean close to norm with only one or two ens outliers, Rain 7th, 9th, and 11th onwards, chance of snow moderate for S Thu/Fri, more likely in N but in smaller quantities, less rain in S Scotland but more snow promised for the NE continuing for a further week.
War is God's way of teaching Americans geography - Ambrose Bierce
Chichester 12m asl