Yup. Mid teens for most during the Christmas week if the 18z comes off. Wow.

There's no consistency at the moment so I'm just waiting for the models to agree on how next week will develop.

It seems even more chaotic than usual at the moment. I am inclined to Neil's view that something may be afoot.  

The ECM 12z ensemble for London shows the op was very much in the mild cluster from 23rd to 26th and almost an outlier on Xmas Day. Still no clear signal beyond Xmas but mild options are limited and the main clustering is arohnd average and cold.

Shouldn't that be in the Brexit thread?

Agreed

There isn't even any stella charts to look at when browsing GEFS 

After taking a break for a couple days of looking at the GFS I have come back on to see the same old rubbish dire charts, showing mild south westerly winds and pizza slices esp the OP run! Despite SSW occurring over xmas we really need to start seeing something colder - it really does look dire and so un seasonal - looks like i'll spend the rest of this December at the winter moaning thread!!

Either this model runs will need to upgrade or the Met office, BBC month ahead and various long range model outputs will have to back off on any cold!!

That chart produces a 2m temperature of around 9c for many, around average for late December.

So here is a straw clutching question. If the SSW hasn’t happened yet, how good are the models at factoring in the forecast of it doing so, into actual surface conditions?

Not quite the weather I was hoping for on Christmas Day but potentially could be one of the warmest Christmas Day's IMBY for some while!

Variations on a high pressure related theme again this morning for Christmas week.

The position of the high pressure and whether we get a fresh supply of clean polar air prior to its arrival is still undecided.

There are fine margins between a mild (ish), benign and largely cloudy week and a clear increasingly cold and frosty/foggy one.

The mean position of the high pressure cell on the GEFS (0z) on Boxing Day.

With regard to snow potentail - zilch. Personally though I'm happy for the UK to be in a stable pattern while the atmosphere gets itself organised by allowing some deeply cold air to start invading north eastern Europe. 

I don't think it is. The models do not seem any more 'chaotic' than at any other time. I think it is just a case of us noticing this more because of we are all focused in on Christmas. 

I disagree. There has been little consistency in recent days, either between models or run to run.

The likely behaviour of the filling low pressure systems in  mid-Atlantic and the position and alignment of high pressure have all shifted markedly. Even at 6 days out in this morning’s runs there are marked differences.

Are we looking more closely because it’s Christmas? It might be a factor but I look at the output quite consistently in the autumn and winter.

ECM is best of the bunch this morning by day 10 with a shift of the HP cell towards the West. The profile at Northern latitudes is poor in all models though and doesn't give any indication of the possible dramatic changes being intimated by the METO for early Jan.

Lots of very cold air to the east; lots of moisture on the Atlantic. But none of the synoptics seem keen to move either this way, and a quiet anticyclonic spell with frost and fog seems most likely.

There is remarkable agreement in the various GEFS runs (at least for the south of England) as to the lack of rainfall after Christmas, consistent with the above. If you want to see a real egg-beater of temperature runs, take of look at the GEFS for Greenland

If this is wrong please tell me.

As far as I'm aware that is exactly the case, the changes in the atmosphere will not get accurately modeled until the event really gets going..

Met Office update today will be very interesting. 

I look at output throughout the year, and rarely is there model on model consistency on a run by run basis at 5 days +. Especially if the Atlantic is in a relatively mobile state. Under more stable anticyclonic scenarios though, I would agree with you. 

Why Brian? It has been solid for days now, I see no reason for it to change? Until the models get a grip on the ssw they are going to be all over the place - just like in Feb.

Thanks for confirming. That's my straw today!

UKMO extended (boxing day) turns winds southwesterly with rain spreading in from the west