Strange one thou CP Jires does have a point if you touch a southerly facing brick wall on a bright winters day in Dec/Jan im always surprised how much conducive heat/energy is taking place.

On ecm it is running to 360 imo probably very limited use

https://www.wetterzentrale.de/en/topkarten.php?map=2&model=ecm&var=1&time=336&run=12&lid=OP&h=0&tr=6&mv=0 

Working for me, just loads later.

12Z run out to t+360 was available on TWO. Access here:

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

Yup, there's a definite shift this morning towards it being a typical 3-day cold spell here in the south, with the block failing to establish in such a way as to prolong the cold. The week 2 subzeros on the good old temp4 chart have gone too, of course, as it reflects the GFS op run:

http://wxmaps.org/pix/temp4.png 

I'm still hopeful that there'll be the first ground frost of the season down here, and an outside chance of an air frost. Any more than that would be gravy!

Quite different up north, of course, and it'll be interesting to see how the snow warnings are refined over the weekend.

Looking across the model output this morning it seems like the NW of Scotland (or further north from here), perhaps N Ireland (mainly higher ground?) and northern parts of England (especially the Pennines?) may be the favoured areas for snow as things stand.

It will be bright, breezy and chilly for many other parts.

Looking at next weekend and beyond there seems to ve a large range of possible outcomes on offer, from cold to mild.

GFS Op 0z - N-lies down the N Sea at first under the direction of LP over Finland, but on Tue 19th Lp develops runs SW across Britain to 985mb Holland bringing much more direct N-lies and unsettled weather. Another LP runs across Cornwall into France Thu 21st, keeping the N-lies going though these never really reach the SW. By Sun 24th the main LP near Finland has filled and moved NW, and a series of  Atlantic LPs are the main influence - Sun 24th 975 mb off W Ireland,  crossing Scotland and dragging in N-lies behind; Fri 29th 965mb off NW Ireland moving to Iceland; Sun 1st 980mb Portugal reaching the Channel the next day.

ECM - Not unlike GFS but the atlantic LPs are treated slightly differently; that on Sun 24th becomes much deeper (960mb) and stormier as it passes Scotland; but dissipating quickly to makes room for another LP from the SW approaches to reach the N Sea 980mb Tue 26th

GEM - less emphasis on the LP Sun 24th but that on Tue 26th is quite deep and cold as it runs up the Channel

GEFS - In the S, cold spell lasting to Sun 24th then switching abruptly to mild before slowly dropping back, fair ens agreement, and rain in most runs at most times; brief chance (1/3) of snow as the cold air arrives on Tue. In the N, cold air arrives sooner and is followed by heavier rain from 24th - fairly dry until then but any pptn probably as snow. Less certainty about any mildness after 24th.  The location combining heavy pptn with low temps to generate a heavy snowfall is NE England and down the E Coast on the 19th.

Me too. I've found it remarkably accurate on some occasions.

For example this chart from the 06z GFS op run has temperatures in the ease/southeast of the UK in the mid to high teens and heavy snow in the northwest of the UK. 

https://www.wetterzentrale.de/maps/GFSOPEU06_228_1.png 

The synoptic profile looks very similar, I do not know what people's memories are like but during the infamous December the cold set in on the 7th with a low tracking southeast from the north Atlantic running across southern England bringing up to 10cm of snow in areas on the northern side of the low. This was followed 4days later with another low which tracked along the channel bringing up to 25cm of snow to some southern areas ( here in southern Hertfordshire we had 15cm). The latest 06z gfs run is toying with the idea of flattening, stretching and disrupting the low which would increase the chances of snow for the south.

The main differences between now and Dec 81 is that this is 3 weeks earlier, and also the sea temperatures that will have an impact on the direction the low will take but, I am confident we will see a move in the models for a more southerly tracking low during Monday and Tuesday.

Talking of Arpege, the 6Z run really winds up the low pressure as it exits into the continent, producing gale force winds with a chance of back edge snow over parts of East Anglia and the SE.

6Z GEFS too my mind look like a slight swing back towards prolonging the cold, although still very uncertain.

Yes, both Arpege and ICON are modelling one heck of a blow - 85+ mph gusts over East Anglia as the low pulls away for the former, and 100 mph (!) over Thanet in Kent for the latter... ICON has a broad swathe of 72+ mph gusts across many parts of England and Wales.

Needless to say, I'm hoping they've overmodelled it. Otherwise it won't be the snow that most people end up talking about!

It all depends, of course, on when (and indeed whether) the low undergoes rapid cyclogenesis... funnily enough the GFS was the first to pick up the potential, a few days ago, but thankfully it too has moderated things (winds in the 40s here, rather than 70s as it showed a few days ago).

The MetO raw for here has temperatures falling from 9C at 3AM to 4C at 9AM, or 6C to 3C for Reading.

The GFS though is far more abrupt, falling from 8C to 3C in just 3 hours here, or from 11C to 2C in 3 hours at Reading!

It's no wonder high winds keep cropping up across various models, as that's going to be one heck of an active front...

Here's the *mean* position of the low at just T+60:

https://images.meteociel.fr/im/87/9719/gens_31_1_60bgo8.png 

As far as I’m aware it is has the same input data as the operational run but with a lower resolution (and no perturbations).

Hopefully a trend!! Next week is certainly up in the air - bit more interesting than usual but think that happens most Novembers. As usual the Euro high will dictate everything!