looks fairly average.

For cold 2 extreme, 2 severe.

For very mild 6.

The rest average.

Ecm still keen on the undercut 

A snowfest between these charts very good ecm again

http://www.wetterzentrale.de/pics/Recm1922.html

http://www.wetterzentrale.de/pics/Recm2162.html

The huge high over Scandi now appears to have a decent amount of support, wasn't the GFS the first to spot this originally? It seems the others have followed.

When the Atlantic comes up against the cold continental block to the East, these situations often bring out the highest levels of uncertainty so how things develop after New Year could vary dramatically depending on the positioning of low pressure around the UK.

For a  severe cold spell to come off everything needs to fall in place. This may not happen first time round but it's good to see a cold pool developing to our east now!

I remember in late February 2013 a cold easterly failed to materialise but the cold pool to our NE remained in place. That then eventually arrived over the UK in March. We may need to to wait a while but it can happen.

Whilst I understand the pessimism of some, we are in a position were things could easily turn cold and the Scandi block is impressive in both its size and intensity (1055mb+) so it will take a lot to shift it.

The output currently is far better then what we could have imagined one week ago. Lets hope we don't end up in a cyclonic pattern as per the 12z GFS. Fingers crossed the worst of the rainfall has passed for Northern areas too.

ECM looks good out in the farther reaches. The overall Northern Hemisphere picture looks so much more different than what we've had to endure for the last couple of months. No point looking for specifics at that range, but the outlook looks colder at least.

Looks like a snowfest to me especially for Midlands 

http://www.wetterzentrale.de/pics/Recm2402.html

GEM12 not onboard this evening.

That's, of course, its modelled size and intensity. A few days ago there was a 1065 modelled moment somewhere out in W Russia. But the persistent modelling of a robust high is increasingly convincing; I think the alignment of that high is going to be pivotal in whether there's a westward incursion of very cold uppers.

Indeed. For the model output tonight, it's all about the trends. From where we were a few days ago, the block-undercut scenario is now no longer in the "very long odds" stable IMO.

Sensible

 nice general run

look at  that profile 

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=1&type=0&archive=0

Really?

What are /were you expecting , take yourself back 7, 8 , 9 days ago

Indeed and close inspection of the day 10 chart shows it really is a snowmageddon stunner!

http://www.meteociel.fr/modeles/ecmwf.php?ech=240&mode=1&map=3&type=0&archive=0

Dont even think about it Brian many more runs required hint pb 

Precisely.

Even on Wednesday, the odds according to many were still very much on a continuation of the recent pattern for at least the first half of January. The model output seems to have changed considerably though since Christmas Eve, and the longer they stick with this theme the more likely it is that eventually, the MetO will smell the coffee.

ECM is pretty stonking  Are the models still just nosing around a potential pattern change before dumping it, or are we onto something? Time will tell as ever I suppose. 

GFS P is obviously showing its superiority to the original

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=264&mode=0&runpara=1

I quite agree David but when easterlies are concerned in the UK it's never too clever to smell the coffee prior to 48hrs before. A step backwards in general today I think, but still a small chance of a cold shot nonetheless. In the meantime more rain this week for areas that could do without it. 

Its seems to me a borderline scenario and these are normally the snowiest but also riskiest. Fun model watching though.

Trends, trends.

Those not blinkered by belligerence will recall these colder runs being commented on in FI by some of us prior to Xmas as part of the ensemble set of the models that although in a minority should not be discounted.

Maybe tonight's 18z will re enforce the theme for cold....

Well if the ECM and to a lesser degree the UKMO are indeed correct we're in for an absolute snowfest from the Midlands northwards, starting from next weekend onwards.

Ramp out of the way and this is going to be one bumpy ride from now until then with lots that can go wrong, the easterly though not textbook could easily be pushed back eastwards if we don't see sufficient ringing towards Iceland from Scandinavia.