Sorry for being slightly OT but we seem to do it to ourselves every year, this is NOT a winter is over post by the way, just highlighting the madness that comes with weather enthusiasm and model watching, we fall into the trap of 'background signals' and upstream events more than ever.

When I first started looking about 20 years ago it was simply the NAO and heights over Greenland,if that looked favourable in November we were getting snow, then it was the NAO, heights and the SSTs, if we were into single figures in November it was a sign of the coming snowfest. Then we added in the waxwings, who can forget the waxwings? Then more recently the PV was the signal, if that looked like splitting we were out buying shovels. 

Now we need the NAO, Heights, SSTs, Waxwings, PV AND an SSW

I'm beginning to think that Bristolian agitator that once darkened these doors was right all along, we are no nearer to correctly plotting the weather passed 5 days out and LRF should stand for Long Range Folly

That could be because, as has been mentioned above, the forecast SSW hasn't commenced yet and isn't due to commence until this weekend as far as I'm aware. My guess is that the models will not start to factor in what changes the SSW will lead to until it is actually underway.

For the avoidance of doubt, I am not saying that when the SSW happens it will lead to changes in northern latitudes that will be of benefit to us in terms of cold. What I am saying is that, as things stand, it is probably too soon at this moment in time to be expecting to see any notable changes in the model output since the SSW hasn't yet begun.

Looks dire so far! Yes met office update will be interesting! Maybe we need to wait until the SSW has taken place for the models to start picking up on this tropospheric response and give us some colder runs!?

Exactly.

GFS looks poor in deepest FI, but I see no reason to place any more faith in that solution that there would be were it showing a massive Scandi High with a strong E/NE flow in FI. ECM does look more encouraging. If ECM and GFS are at odds with each other for the period of the next 10 days, there is no way anyone can be sure of what happens longer term.

What does appear to be quite likely now from what I am seeing is that post-Xmas, the weather is likely to settle down for a few days anyway as HP moves in. How long the HP stays around, where it positions itself and then what happens beyond that is what is still to be determined.

I think some of us may be expecting too much a wee bit too soon, tally. The MetO were consistent with their thoughts and were ultimately proved to be spot-on at the end of February when some here had been doubting them, so I don't see much reason to be doubtful of them now.

Until the SSW happens and the effects of it start to become clear, then I think the model are going to continue to struggle somewhat just as they are doing just now and they did back in February.

That’s interesting because I’d have put it the other way round.  When the weather is more conventionally mobile the pattern is generally quite clear, although the precise timing of the passage of systems varies a little.  It’s when the jet stream is weak that the models are less able to predict developments. That is borne out by the verification stats which show less accuracy in the summer and more in the winter.

It’s also worth noting that the Met Office forecast talked about the end of December before high pressure was likely to exert some influence and then mostly for the south. The reference to snow came into the January period.  That suggests strongly high pressure to our south initially, which is what the models are showing, albeit without much consistency yet.

I thought the ECM 720 runs today? Could be wrong.

What is notable also about this morning's model output is the ECM, GFS & UKMO charts for 144hrs don't all seem to be singing from the same hymn sheet, as shown below:

http://www.wetterzentrale.de/en/topkarten.php?map=1&model=ecm&var=1&run=0&time=144&lid=OP&h=0&mv=0&tr=24#mapref

http://www.wetterzentrale.de/en/topkarten.php?map=1&model=gfs&var=1&run=0&time=144&lid=OP&h=0&mv=0&tr=3#mapref

http://www.wetterzentrale.de/en/topkarten.php?map=1&model=ukm&var=1&run=0&time=144&lid=OP&h=0&mv=0&tr=24#mapref

I often think that whenever there is any divergence between the big three models as early as 144hrs, that is a sure sign of considerable uncertainty going forward.

My recollection from February is that it was about a week or so after the SSW had taken place before the models began to pick up the arrival of the Beast with any real consistency. For a while they were all over the place but from what I remember, by the time we got to within 10 days of the Beast coming, the models that we have access to were more or less in goor agreement about it.

Yes, the link changes with the output.  This morning's ECM was closer to average, but on still on the milder side of it.

Meanwhile the UKMO day 6 Christmas Day chart is definitely a mild one...

Where did the one in Feb take place. You might have snatched my last straw 

Over Canada. (Although there was also a lesser warming over Siberia at first, and later over Scandinavia)

It needs to lead to a genuine split in the PV - that opens the gates to cold.

The forecasts are still good for that, although there may be an interim period of the kind you suggest - the clever money is on the cold being delayed until the New Year.

Ensembles look roasty toasty for my New Year’s Eve bbq. Not my idea of seasonal but Christmas will be over by then and we can all look forward to spring with dire output for cold prospects.

http://old.wetterzentrale.de/pics/MT8_London_ens.png

A couple of members fall off a cliff at the end (only relative down to average) but generally speaking you’d expect met office long range to change drastically soon unless the models fall in line with their theme.

Well, comparing the current strat forecast to the SSW in February, it seems clear that it's much weaker and shorter lasting than February's. 11 days after the strat first goes above 0C, the vortex is still powerful and right over our side, while the warming has more or less fizzled out (no yellow colours left) :

Contrast that to February, when it reached 0C over Canada on Feb 15 and still looked like this 11 days later:

depending on how it sets up it could in theory strengthen the cold if we have decent pattern bringing in cold

My guess is that anything will be prefaced with "low confidence..."

Looks like a significant shift towards a less cold outlook for the rest of this year and more uncertainty during January.