Jetstream throwing a big loop with strong S-wards flow on the Atlantic, down to Spain and returning N-wards weakly up to Norway. This lasts to Tue 8th with UK pretty well in a cut-off low. Then the jet concentrates on a S-ly flow through the Med, the UK at first well clear to the N of this but the jet moves ti affect Southern UK on Wed 16th (and a right muddle on Fri 18th!). BBC describes our position as between two blocking HPs, one to W and one to E so a spell of LP going nowhere.
GFS concurs with LP Kent Fri 4th 980mb, looks like rain or marginally snow almost anywhere, fills and progressively loses its Arctic feed by Wed 9th. New rather flabby LP in from the Atlantic which settles over N France Sat 12th, filling but followed by another which hooks up to form a trough from mid-Atlantic to Spitsbergen Fri 18th with tempting-looking NE-lies on its northern side, at that stage only affecting Shetland.
GEFS mean of runs 2-3 C below norm at first, gradually recovering to just below norm ca Wed 9th (sooner in N & E) and staying there to Fri 18th. Very good agreement and first and not too bad later in with few outliers. Heavy pptn around Fri 4th, less in SW but prolonged in N; some rain (could be snow on high ground) on and off throughout after that . more than forecast yesterday and increasing towards end.
ECM brings the new LP in earlier, and not flabby; 985 mb Brittany Tue 8th. but then shows the Azores HP beginning to push LP away to our E by Sat 12th; just the hint of a small trough over the Hebrides in contrast to GFS
Edited by user
02 December 2020 08:02:56
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Reason: Not specified
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Chichester 12m asl