https://www.meteociel.fr/modeles/gfse_cartes.php?ech=384&code=0&mode=16 

If that happens I'll bank it.  It would be nice at least to have a cold Christmas day compared to all the recent years. 

I know that folk in the SE and E look for a Scandi High as the winter utopia, but for many of us outside those areas (Especially in NW England, W Scotland, N Wales), the set-up of a deep Scandi low (extending west to Ireland) and either a Greenland High ridging south or Azores High ridging far north, to bring in a cold and unstable NW'ly flow (ideally with a front sinking SE;wards down the west of the country! 😁), is what delivers better.

Roll on Spring, I'm bored of this seemingly eternal Autumn. 

The GFS 12z take on the Azores HP in the run up to Christmas mirrors some of it's earlier runs, with a chilly west/north west flow turning more northerly as a ridge forms to our west. I'd tend to view that as a triumph of timing in a mobile pattern and on this run the air is only really cold enough for wintriness for higher parts of Wales, N.England and Scotland (usual maybe lower levels here too).  Still chilly and breezy but with a bit of sun would be infinitely better than the current crud!

Were such a set-up to verify later this month as suggested by some models, I am far from sure that any wintry precipitation would be entirely confined to high ground.

Without upsetting anyone hope it’s further south

GFS Op 00z - Current HP fading and new cell established over France 1035mb France Mon 16th with ridge to Scotland. LP then runs up the W Coast to deepen 960mb Shetland Thu 19th bringing trough to cover Britain which, augmented by more LP from Iceland, generates strong NW-lies by Sat 21st. For the whole of Christmas week HP resumes dominance over the south of Britain with strong W-lies for all, a weak embedded trough passing through late on Christmas Day. (typically 1030mb Channel, 990mb N Scotland)

ECM - like GFS at first though LP Thu 19th moves to E Iceland so affects Britain less; then the following NW-lies back to a full-on N-ly from an Arctic source on Mon 23rd.

GEM - more like GFS though the LP Thu 19th although further off (980 mb S Norway) has enough power to generate N-ly gales for Britain on 19th and 20th, and HP resumes more quickly afterwards.

GEFS - milder Sun 15th - Thu 19th dropping sharply to cooler; ensemble agreement doesn't last though the mean slowly recovers to norm by 29th, pptn starting around Wed 18th and continuing with moderate amounts in most runs, but not much in the east. Snow row figures for Christmas Eve/ Christmas Day minimal for S England, about 10/33 for N England and E Scotland, about 20/33 for Glasgow and Inverness

Yes Q, I see both control and Operational 12z are going for a cold Xmas but will the other models agree and will this come about!?

Control at +288z:

Operational @ +288z

The GFS 18z run beyond Day 7 is sharply different for our part of NW Europe, with the complex trough that develops from that point totally absent.

GFS Op - HP developing over N France early next week, declining as trough moves up W coast of Britain to 975mb Shetland Fri 20th, trailing weakly across Britain further south. HP moving in from SW by Sun 22nd, centred English Channel 1035mb Thu 26th, slowly moving E-wards as another trough runs up the W coast Mon 30th. For Christmas Day itself, mild and dry with wind from a W-ly point.

ECM - similar though the LP 20th then drops S-wards into the N Sea for a couple of days with colder NW-lies, slower to clear, until the HP arrives Christmas Eve, a couple of days later than GFS

GEM - between the above two, if anything closer to ECM

GEFS - rather mild 15th-19th and (with much less certainty) 23rd - 27th (op and control runs in the SE outrageously warm 26th, 12C above norm); cooler periods between. Rain for the S around the 20th, declining and dry by end of period. Rain in the NW continuing throughout. 

And again this morning. It’s easy to get suckered in by the swings in output but my recent ‘smoothing’ approach seems to be working (completely disregard any particular outcome beyond 180, and only accept an outcome beyond 120 if it’s repeated several times by the same model comparing successive issue time specific output - i.e. 0Z v 0Z; 12Z v 12Z etc.). 

It works fairly well, but of course there’s no fun in it and for old times sake I still examine every chart 😉

https://www.wetterzentrale.de/en/show_diagrams.php?geoid=49069&model=gfs&var=2&run=0&lid=ENS&bw=1 

Unsurprisingly every evolution looks plausible, then you go and look at the postage stamps and discover that each of them also looks plausible… It still amazes me just how much a minuscule change in the opening position can produce such radically different outcomes so quickly. It’s also a sobering reminder that because we will never have a perfect snapshot of the state of the atmosphere, no matter how much computing power we throw at it there will always be uncertainty eating away at the output.

That in itself speaks volumes. Coupled with the striking yearly warming trend and you can see how difficult it is to get enthusiastic about winter prospects.

Best cold zonality I ever remember was January 1984. I was living in Lancashire then and my goodness it was incredible. Gale force north westerlies and maxes below 0C and frequent very heavy snowfall.  🙂