FAX - today there is an extended trough from SW Iceland to N Spain with fronts slowly working their way into Britain from the SW. y Tue 23rd the whole complex shift S-wards (centre Biscay 1000mb) and E-lies are getting established for Britain, becoming quite strong Wed 24th between HP S Norway 1041mb and LP by then 1001mb Sardinia. Weak disturbances in the long-fetch E-ly affect S Britain.
GFS Op 0z - similar evolution but by Christmas day the HP is 1040mb northern N Sea and although a modest cold pool is then moving along the Channel. the E-lies are turning into the SE with less prospect of really cold weather. The HP centre then moves to NW Scotland, 1045 mb at times, with a further shift of winds into the North, nothing dramatic at first but for New Year's Day, Arctic gales developing. On Sun 4th, the cold air thus brought S-wards lies over England and a major depression 975mb is approaching the S Coast from Biscay (Well into FI, of course, but the best prospect for a New Year's blizzard in England since 1987 IMO - but don't get too excited yet).
ECM - evolution to Christmas much as GFS but then the HP cell retrogresses more than GFS, to mid-Atlantic by Mon 29th, far enough for N-lies down the east coast at an earlier stage. However, it then brings the HP back to Britain, cutting off any N-lies, 1035 mb New Year's Eve, and then up to Iceland for Sun 4th. At this stage the pressure distribution is much as for GFS but the cold air hasn't penetrated S-wards and cold rain is more likely for England.
AIFS - London and Edinburgh similar to each other, maxima drop to 3-5C from Tue 23rd (briefly milder Sat 27th), rain Mon 22nd, dry thereafter.
GEFS - Postage stamps unexciting for Christmas Day and beyond, with nearly all showing HP around Britain and across the N Sea to Norway. Line graphs - mean temp dropping below norm Tue 23rd and staying 2-3 C below in the S but close to norm in the N into the New Year. However, there is with a lot of ens variation, more than in previous forecasts e.g. on the south coast Tue 29th , op at 6C and control at -10C. A splash of rain this Sunday, then mainly dry. Snow row figures about 50% for S England Christmas Day and/or Boxing Day, otherwise less than shown yesterday, in low single figures/33.
https://www.netweather.tv/charts-and-data/snow-risk has interesting predictions of snowfall for the south on Christmas Day, and around 3rd/5th Jan, Scotland at New Year, and for the east coast quite frequently in this period.
Edited by user
20 December 2025 09:30:13
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Reason: typos
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