He used to be a regular poster here before he went off to do his degree in meteorology.  He knows his stuff well enough.

ECM 12z ensemble for London

Two markedly different clusters for much of next week, with the Op taking the less cold route initially before taking the colder route until after next weekend: GFS 12z Op headed towards cold but there’s a lot of spaghetti there. 

So, still finely balanced in the next few days and anyone’s guess beyond that.

Daily forecasts chopping and changing over the next few days as more or less weight given to LP to the west and HP to the east, varying with each run.

Christmas Day now appearing in the outer reaches of FI and a promising northerly appears with snow showers for the east coast and impressive double-digit snow row figures for Inverness. Just the sort of set-up which has disappointed before, but it might just be worth a punt on a White Christmas for east coast locations.

Just saying....

Surprisingly good ECM this morning cold air much further west. -6c 850s at 96h, -7c at 120h and even some -8c at 144h. Remarkable,  Models really are struggling with this one. Ecm suggests snow very possible late next week.

Yes snow possible on one or more of the attempts but this is still open to interpretation.

It’s one thing being a partisan coldie, but when that blinkers you to any other scenario being modelled it becomes a bit annoying.

In the extended (up to Xmas) and the forecast PV displacement from a warming on the Siberian side coupled with synchronous wave 1/2 activity continues to excite the long-rangers.

ECM went off the scale this morning.

GFSP 00z still suggesting some transient sleet or snow.

Beyond that things looks very messy and generallly unsettled on this morning’s charts.

Needless to say that things could change and then change again. However, the main weather risk at the moment is the growing possibility of flooding.

Well we have a pretty dry three or four days to come, and beyond that that chart doesn't look particularly wet for this time of year. So at least for the SE, I don't think there's too much to worry about. It could be a different picture further north and west, of course.

Here are the charts for rainfall and anomaly over the next week and beyond (based on the GFS 00z op run).

This morning's ECM (which wasn't the coldest run of the pack, although it came close) still won't entirely give up on the snow risk down here - this is the London 0z ECM suite:

Full charts available as ever on weather.us:

https://weather.us/forecast/2643743-london/ensemble/euro/snow

(I still don't understand why nobody else seems to use it!)

That looks odds on IMO , we need to put the East to bed for a bit 

Atlantic is definitely coming through but its whether we can get any snow when it does we have a small window Thursday  to Saturday looks unlikely  but we still have a chance. After that its looks like a long wait until anything significantly cold . Probably  after Christmas. We need the SSW to be kind as well.

Nothing of note at all over the States either 

LP after LP being thrown across the Atlantic , need to conjure an HP up from somewhere , patience is the word it seems . 

FWIW, there's been a marked switch back to a colder outlook down here at least from both MOGREPS and EPS. Both of them have ensemble mean highs of just 4C across Kent on Thursday, with 4 or 5C for Friday - both of which are in a strong east or ESE'ly wind. It'll feel perishing, even if nothing else.

(It's also a good reminder that just a day or two of easterlies at this time of year can feed in some low-level cold.)

Beyond that, nothing much of excitement on offer from a winter fan's point of view. There are hints - just the odd hints - via GEFS of some warm advection attempts west of Greenland in the 10 day+ timeframe but at the moment they're not really worth paying much attention to.

Well, if this was the middle of summer just now, we would certainly be looking to get some high pressure from somewhere. At this time of the year though, it's not just about looking for high pressure as per say, because that could easily end with the high pressure in the wrong place such as to the south of here which would then result in that bringing in really mild air from the Azores.

This means that the high pressure needs to be in the right place, preferably to the north of here where it can then bring in a properly cold easterly wind from Siberia and hopefully, not the sort of half-hearted easterly which we got in November that wasn't all that cold, and which delivered nothing more than a lot of gloom which was then enough to prevent that month from being sunnier than average overall here.

Eyes on the *possible* SSW now. That said, the warming is only being shown out in FI, which surely is about as likely as any other FI chart.

Id have thought that was a given 

Ah yes, that easterly that brought sleet here and, further inland (near Ashford) some snow:

(That's Gizmo, one of the Snowdogs from the recent art trail held in Ashford).

I'm not expecting a repeat this time, but two easterly shots in the space of 3 weeks is interesting to me, as it suggests a bit of a repeating pattern. If (big if) we get another go, that'd put it at the end of the year / start of next - we'll see soon enough!

All for fun of course but get the HP to balloon up over Greenland and bingo