The GFS 18z at 156t is shaping up to being a peach of a run for coldies. At that stage it looks like the Azores High is about to pack its bags and go for a Winter holiday in the Southern Atlantic Big changes from the 12z with energy flooding South from the low off the seaboards.

A one off or a trend I wonder

Turning into a classic. T+186:

Just one run and it will change - but this run provides falling snow every day of next week thus far in my neck of the woods (west West Midlands). Pity it won't turn out exactly like that.

Excellent from GFS looks like a quite wintry week for some areas of the UK

Get your shovels ready, some parts could see some heavy falls of snow

Remember J F F

The next lot of white stuff hits the North

Snow moves across the UK, rain in the SW

Many places seeing snow at this point

Wintry picture continues

'could' be one of the snowiest weeks we have seen

All J F F of course

We are never this lucky..............are we?

Superb from GFS , a raw cold Easterly setting in

This run will no doubt be a rank outlier - synoptics like this are rare enough in virtual space let alone for real LOL
+240 and -12 uppers in to the East - heavy convective snow developing here. Atlantic locked down and a reload looming from directly North.
This is a pub special with M&S style.

Now that does deserve a Brrrrrrrrrrrrr

I agree, it is far too good and as I say we are never this lucky, surely?

This GFS 18z run days 5-7 is a bit better for snow than ECM, not quite as good as the GFS 12z though.

The main difference to ECM is a slower progression of the low that is situated south of Greenland on day 5 - this gives more time for the warm sector to occlude out.

Having said that, frontal precipitation intensity steadily reduces once the occlusion process is complete, and before too long it dissipates completely, so like with so many snow related parameters, it's a case of not too little, not too much.

Now I find myself wondering if the slower progression on the GFS run is down to more in the way of higher heights near Iceland, or if those higher heights are due to the slower progression of the low... given the position of the high it's affect on the jet would be via disrupting it, slowing it as a result, so the higher heights could be the driver. I'm not really all that sure though - the jet could just be weaker as a result of adjustments elsewhere.

I have read some posts lately on other forums from respectable sources which talk about the warming we saw early in January now propagating down to help those higher heights be sustained and disrupt the jet. Similar to January 2013 I think. It seems plausible - I remember considering the possibility back in the first few days of the year, then losing focus on it when the MJO started acting all energetic.

ECM and UKMO really throw that low toward the UK, giving it little time to occlude out. UKMO has an enormous amount of disruption going on which seems to save the day, while ECM just seems to bundle all of the development potential into a remarkably rounded system and well organised system for a disrupted jet regime. Too much so? A good bet based on the ensembles which favour a weaker, more disrupted system based on the mean 500mb and 850hPa charts (I will be looking for word on the spreads).

So in terms of how soon the system influences us at all, we've essentially got progressive ECM and UKMO runs versus a considerably less mobile couple of GFS runs. Not something we're used to with sliding lows!

Somewhat worryingly for those right down at this end of the UK, we now have neither end of the scale delivering for the far south and SW. 

What the GFS 18z has for us days 8-10 ongoing does a fair job of trying to compensate - the pub run living up to its name - but at such range it can't erase the sense of concern with regards to next week.

Still, that run at day 8 to 9, in terms of the general arrangement of heights at least, is not far from what the ECM ensembles have as a day 11-15 mean. Yes, the average of all the members!  Quite something really.

This post from Steve M on NW caught my eye... I think it's clear why! :P

well *IF* it lands this will be the icing on the cake for most

http://modeles.meteociel.fr/modeles/gfs/runs/2015011418/gfsnh-1-216.png?18 

THAT is a snow machine for the NE. you may as well wave goodbye to places like Durham etc.

PLUS blocking to the west tilted & aligned favourably for sustainability

S
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Odd there aren't more on here, normally there would be hundreds packed into this thread, I wonder if last year has knocked the belief out of some?

Did I miss something? Extraordinary run from GFS. Only one run, to be taken with as much salt as it suggests we might need, but when MBY ends up benefiting from a massive slider low across the country, only a few days later to have results from a convective Easterly, you must say we are looking at a stella run. It will be one of the colder, if not the coldest options, but certainly indicates why the MET have been talking up possibilities on weekly outlooks lately. The best run from an IMBY perspective for years, but nationwide this would present major disruption in virtually all areas - apart from the absolute extreme south, and even then perhaps only for a while midweek. All to play for - but equally, all to lose. Only one run and all that....or is it?? 

Lake effect? :p

Well its not though is it, GFSP has been showing the Easterly for a few days , so the hints have been there, we will just have to see if they come to fruition

i reckon you may have a good point there Gooner....we are so used to downgrades....😁

Itch my chin