Can you send me link to the above please?

Does anyone kn ow what 1hpa is like and if it's worth keeping eye on temps at that level in stratosphere?

Oranges and red's/ warmer uppers in strat do infiltrate in from Siberia into the Arctic N. Pole at end of the 18z run - this is now a consistent thing!! - if things work out 'accordingly' then watch out for January!? - SOme major changes aloft !

ECM 12z ensemble for London

Now a very strong consensus across the ensemble and the Op regarding Wednesday and out to day 10. Highs on Thursday and Friday around 3-4c then a rapid climb to 13-14c on Saturday as the milder air finally pushed NE.  It’s noticeable that the GFS 12z is a mild outlier v ECM through most of this week.

The greater confidence from the Met Office would seem to reflect the tightening up of the ensemble set today.

Beyond Day 10 there’s the usual uncertainty but evidence of a shift towards average and colder options as Christmas approaches.

GFS 0z-

The stratospheric fuel warning light has just come on with no petrol station in range

Looks good but both the BBC and Met Office not seeing any significant cold for at least a month in their forecasts. When do you think the UK will see an impact from the SSW?

As I said over on the other forum, I think a range of 30th December- 15th Jan should just about cover the period of interest as far as I'm concerned. So, a while to go. Should be some fun popping up in the modelling shortly though as the predicted SSW gets closer.

It's initiating circa day 10 at the moment.

GFSP is even more striking with the warming by the way- up to +8c. Impressive.

Toasty strat

Thanks, hopefully the BBC and Met Office should start mentioning significant cold soon then in their monthly updates.

The other thing with those stratosphere charts is just how cold it is in the vicinity of the UK - I reckon we'll be seeing these in a couple of weeks:

https://en.wikipedia.org/wiki/Polar_stratospheric_cloud

At closer range, though, ECM shows a transient snow event on Saturday as the Atlantic engages that cold air over the UK:

https://weather.us/model-charts/euro/great-britain/significant-weather/20181215-0600z.html

Quite a bit of snow "up north" from that on today's run.

GEM this morning delays the snow until Sunday, but with more undercutting going on it brings a good deal of snow across much of the UK:

http://www.meteociel.fr/modeles/geme_cartes.php?&ech=144&mode=2&carte=2

GFS, meanwhile, just shows the Atlantic ploughing through on Saturday with no leading edge snow at all. Bah, humbug!

Im reluctant to suggest caution about Strat forecasts and their implications but an SSW, like anything that’s modelled, has to happen before it does and even if it does the effects may not be beneficial to our small segment of the planet in terms of surface cold.

Waiting game on this one IMO

I have the same concerns,  CC knows far more than me about the Strat, but the fact the Pros haven't mentioned any cold yet is a worry. 

What I would add here is that while the models are not showing a major cold spell coming any time in the next couple of weeks, they don't appear to be indicating a mildfest either. Many runs at the moment seem to be sending the jet stream quite far south into Europe with lows passing more or less right over the UK rather than a SW-NW trajectory to the north, as quite often happens. It's a pattern that happened a few times in the first couple of months or so of last winter, IIRC.

Lets not forget that strat warming isnt linked to us being cold.  Its linked to changing major influences on our weather which leads to an "increased chance" of colder weather. 

Its easy to get carried away when its spoken about so much

Watching Gavs breakdown of strat events the other day, and he pointed out that the near record breaking cold spell in December 2010 occurred without any strat warming at all. Surface cold in around the Arctic region was a much bigger player that month. 

Yes look at latest strenght of zonal westerlies at 60'N on weatheris cool - it shows from end of December into January and most of if not all of January we are due to go very negative some go in reverse:

FWIW I am not aware of there being any SSW before the late Dec 2009/early Jan 2010 severe cold spell either. I think there was such an event a little later in 2010 (think it was February but not certain of that), but it came after the coldest weather had passed although I remember the cold lasting well into March that year.

The fact that we can get very cold spells without significant Strat warming or polar wind reversals may be just as well - proponents of the Strat temperature will notice that GFS 06 is much less keen on significant Siberian sector warming at 10HPa than previously.

We have another 'pizza' this again?

Looks similar to previous runs to me 8c on Christmas day .

Really?? Where?? Not in your neck of the woods it's not. Forecast I can see is circa 7-8, hardly exceptionally mild !! You are such a mild ramper lol.

Have another look at Saturday 18z. 14c is exceptionally mild for mid December.

Back to the SSW that's being consistently forecast by models: - Latest on 06z run.

I wanted to ask does the center of the warming i.e 0c or +5c have to be directly over the North Pole or just within the Arctic circle to have a major SSW - it get's up to -15 or -10 at best but the warmest strat air temp is 0c or +5c and on meteociel it's +8c but this never get's directly on top of N. Pole it stays off the top of N. Siberia?