Yeah looks like there's been quite a big shift from the GEFS tonight.

You could say it means the cards are in the pack this year, it’s just when (and if) they’re  dealt.

As I was saying the other night...all the warning signs are there that we're about to enter the freezer good and proper in a few weeks time. We look to be building the foundations of a potentially severe spell of winter weather...possibly at the coldest part of the winter. The strat vortex looks toast in the longer term too.

ECM 12z ensemble for London:

Still a clear signal for a marked cooling through next weekend but there's markedly more scatter now with more milder/less cold options which pulls the mean up.  The previous dominant cold cluster fades towards the end of the run.

Oh dear, now I'm getting really interested but we all know what happens when I do that!!  Exceptionally good GEFS 18z for Guernsey and so early in the season too but will it be there at T96??

GFS 0z not so keen as the 18z!

The models are toying with something!!

GFS is a bake from a coldies perspective but GFSP (which verifies ever so slightly better) is a lot more interesting.

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

This morning's ECM is a corker, too, also with a high to the NE.

Let’s see how this runs, but uncertainty reigns in model town.

Sadly the ECM charts would deliver a sleety mess, at least down here:

https://weather.us/model-charts/euro/great-britain/significant-weather/20181212-1200z.html

ECM 00z op was also anomalous.

GFS operational pulls out a dartboard special to flatten the block before it gets a chance to draw in much cold air. The parallel run is more interesting but it looks like the usual several attempts and teases before anything actually happens. Based on the ensembles a brief cool and settled snap in a week’s time seems likely before more mobile conditions prevail for a time.

from the winter forecast that ive been reading I cant see any prolonged cold spell this winter but only more of cold snaps than spells. from what I gather. seems to be a lot on rain and mild mentioned in the seasonal forecast this winter...

The few I take any note of (TWO, NWx and GavinP) on the contrary go for a likelihood of colder than average LATE with more HLB in Feb, which of course is suggestive of N or NE spells rather than snaps. 

Which seasonal forecasts do you reference?

And as if on cue IF has just tweeted this:

W COUNTRY: "A modest increase in the probability of colder-than-normal temperatures" for winter overall, suggest @metoffice in their latest probabilistic outlook, with "the chances of cold weather related impacts, such as snow, highest in the later part of the outlook period".

GFS 6z has big Scandi high by day 9. easterly incoming. Will the Pros start to forecast this as its a growing theme?

I cant wait for the ground to dry up a little... an easterly wind will help with that.

Shades of December 2010? This may be a forecast SSW, or just a PV displacement, but the PV is likely to be shunted to a more favourable location for us in a week to ten days:

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/winterdiagnostics/index.html

we could get a monster GH out of this and at the coldest point of winter interesting