Really?  - The S and E and EA Are so different to Yorkshire and other northern and western regions, in both rainfall totals and geography, because the chalk substrate areas need a far more sustained and steady rainfall, due to the Chalk’s pompous substrates, so there is no spate and catch. The borehole abstraction depletes these aquifers ever more quickly from new development demands, and yet to replenish them, the need is for steady sustained rainfall to refill the aquifers. Some once permanent Chalk streams, such as the Gadder,  In EA are running again, but the winter / spring lakes and streams In the same region are dry as a bone, looking more like early autumn than winter. We need a lot more rain for these and other chalk areas. Much as I prefer dry weather for liveability - the sight of chalk streams that have never before been dry - being lifeless, growing weeds on the bed of a once gravelly, gin clear chalk stream is a truly sad state of affairs. Unique DNA strains of trout for the particular river, able to be more resilient to disease through centuries of evolution, have been lost, and the otters that preyed on them too, let alone the ecosystems that supported them. It is very sad to see it. Rainfall totals have been very variable according to region with the west and north doing best, but there is no doubt whatsoever, that the south and east needs more rainfall this winter, steady and sustained. 

GFS Op 0z - that feature does indeed arrive as a small intense depression 970mb mb NI Fri 19th but soon swallowed up by the parent depression to the north. Then something of a pattern change as pressure rises over W Europe; after a  week with Britain on the edge of HP centred Germany/Poland, the Azores high takes a hand and an HP cell 1030mb is centred over Britain on Boxing Day which persists to at least Mon 29th, though weakening. This matches the course of the jet stream which switches from a southerly track to a more northerly one after the first week.

ECM - differs from GFS after Fri 19th The 'feature' moves S-wards rather than being swallowed, and appears as a flabby LP in Biscay 1000mb by Tue 23rd while pressure rises over Iceland 1025mb. This HP extends S-wards to (mainly N) Britain while the LP also moves S to Spain. By Sun 28th there is an E-ly of sorts for England, but not cold, indeed any 'real' cold no nearer than Russia.

AIFS London maxima around 10C now, more like 6-8C in Christmas week, a little rain w/b Tue 16th (heaviest fall on 18th). Edinburgh very mild (13C) now, down to about 5C for Christmas week, rain heavy at first, slowly dying out by Mon 22nd. Inverness might have an ice day on Christmas Day

GEFS - nothing exciting in the postage stamps with cold and disturbed weather staying near Greenland, Britain on the fringes of this with occasional interventions from Azores/continental HP. Line graphs, for the S very mild to Mon 21st, then mean near norm for the Christmas period (by 28th as many cold ens members as mild ones), chances of some rain w/b 21st. For the N, periods of very mild 15th and 19th, then mean near norm but a bigger spread of ens members than in the S, rain mostly in the first week, perhaps a little near Christmas Day. Various places in the east have snow row figures of 2/33 for Christmas Day, zeroes in the west.

https://www.wetterzentrale.de/maps/CFSOPEU00_3960_1.png 

🤡

Yes, though the issue is often these days, even if you get the synoptics you were hoping for (which is hard enough), there is no cold air to tap into.  

The GEM looks good on paper but will probably just be cold, drizzle and cloudy.  But at least it will feel seasonal

A waft from the east is significantly better than the current offerings.

Nothing wrong with a Christmas tug.

https://www.wetterzentrale.de/en/topkarten.php?map=1&model=aifs&var=1&run=6&time=360&lid=OP&h=0&mv=0&tr=24#mapref 

If I was to stick my neck out for what we'll end up with in around 10-12 days times I'd go with:-

Most likely - HP to settle over or near to the UK, cooler and essentially dry - cloud amounts will dictate frost/fog amounts. If HP brings in an easterly flow expect chilly and drab as there's no properly cold air nearby to tap in to and it looks like a fairly short fetch easterly at best. Could maybe get lucky IMBY and have a SE flow, that usually ends up a little clearer for me. 

Less likely but still a reasonable chance - HP to settle over the near continent, keeping it dry for the south eastern quarter, with maybe some frost here but milder and more mobile as you head further NW. Much less unsettled generally though.

Least likely - brief HP blip before zonal flow returns.  

Whilst it's more common for HP spells to gradually subside and allow milder air to roll back in there is always the chance that the pattern persists, cold air pools a bit closer to the UK and the HP moves far enough north to allow that cold air to head our way. Unlikely but a lot more chance from the setups being shown than there was when it was zonal to the end of time!

Hi Brian, didn't the 1978/79 winter also start off fairly mild before the severe cold set in? I think I read once that 1946/47 also started rather differently to how it eventually turned out and December 1981 began with a first mild week or so.

Just a bit more concern if this HP will deliver weeks of gloom, frost free and no sunshine?  Need to be in a right place to deliver proper sunny days and hard frosts at night, allowing  the ground and sea temps drop a lot just to be ready for snow if the HP move to good position to bring deep cold and snow.

Yes I think 78-79 was quite mild until the second half of December. 

Don’t forget that the widespread and heavy snowfall on Boxing Day arrived after a period of freezing fog and a bitterly cold easterly. The ground conditions were about as favourable as you could want.

Looking at the reanalysis charts, the freezing fog likely didn't begin until around the 20th. The month was changable and windy up until then,  though with broadly WNW to ESE trajectory, meaning that mP flows were more common. What is interesting is the collapse of the Eurohigh in the days before the cold hit, and which seems to have happened with stressless ease in winters gone by.  

It was also a very cold year. I only mentioned it to try and inject some Christmas spirit into this thread. 😊

https://www.theweatheroutlook.com/twodata/cet.aspx 

Interesting. Looking at the ERA SST anoms for Dec 1962, they were broadly above average over the N. Atlantic, though near or slightly below closer to home.  

Fogs are another thing we see very little of these days, along with Scandi Highs, and I don't just mean the smoke-filled smogs that were a feature before the Clean Air Act. From an increasingly random memory, there always seemed to be fogs which disrupted my journey home from university in the early 60s, and lethal fogs driving down the M6  in years either side of 1970, when I was working in Manchester and visiting parents/parents-in-law in the south for Christmas. Nothing quite like that sticks in my mind as a personal experience so far this century (and don't get me started on London 1952!)

The last 'traditional' and persistent fog I can remember reading about caused a major accident in December 1984 on the M25. 

https://api.parliament.uk/historic-hansard/commons/1984/dec/11/m25-motorway-accident 

This following SST anom map for Dec '62  is even more eyebrow raising. More finely tuned to the 61-90 average. (as opposed to the century average in previous image)