Both have the -10c isotherm heading through the country. - But control delays it.

18z Control @ 240z:

18z Op @ 240z:

9.55 bbc weather showed very  cold air flooding SW wards later next week 

Yes - agree - even if 2/3rds of the perts support the scenario of deep cold for Feb, pert 10 and 17, amongst others remind us nothing is nailed on until + 72, and not even then occasionally. Tempting though it is to start ramping, and despite thinking that this should repeat 2018 at least, we’ve seen it before go P T...even after confident announcement on the BBC forecast...but I am very interested...I think that explains the quietness tonight, its tantalisingly close - but still very much in the prime danger zone for that Latin species quoted above - TV...

A very much improved GFS Op 18z and the majority of ENS are showing a potent East/N.Easterly from mid-run.

The 18z para shows how it can badly wrong though. The trigger low doesn’t sink, lets the Atlantic in and we end up with a Euroslug. It has some support from a few ENS but they're very much in the minority.

So another step forward tonight, but stacks of hurdles ahead no doubt.

Very good charts I agree but the timescale continues to slip back a bit which is always a worry.

Yes slight worry - the cold is being pushed back yet again - it was always due around 4th or 5th but now it's 6-7th February - I mean will we ever get there!?

It's still a messy picture - Control goes mild in FI - Operational stays cold. Parallel brings up a southerly wind in FI stages, ECM is - well God knows! - ECM has cold air nearby but also has very warm air to our south. It's a very confused picture really.

One would have thought that nearer the more reliable timeframe there would be more certainty and some 'cross model agreement' but instead we are getting more uncertainty and more 'cross model disagreement' - so the exact opposite. - How frustrating this is!

One of the best GFS runs I've ever seen this moning - a textbook easterly with widespread and prolonged non-marginal snow.

The fun stuff starts in a week's time, then it keeps going for several days.

Precip chart at 240, note how even Aberdeen gets snow. Also note the sheer extent of the snow hatching, it's rare to see so much of the map area affected by it.

 As I'm working from home today (so no commute), I'll post the "ensemble watch" a bit later, with the 0z data added.

The classic example would be Feb 1986 (a month of snow here, which led to my mum and dad having to dig a path along our road for the hearse at my grandpa's funeral), followed by Feb/Mar 2005 - which had snow falling every day over a 2-week period (mushy stuff, but it still covered the ground).

You don't even need a sustained pattern if the cold shot is deep enough, 1987 comes to mind: that -20C 850 blob dumped so much snow it took weeks for it to all melt.

Obviously one's views will be tempered depending on the location. Down here, with 5¼ inches of mostly cold rain this month I would welcome even a 3-day easterly blast right now. Further north, where there's been rather more snow in the mix, things may well be different!

When I wake up and see Darren has posted at this time, you know there’s been a good 0z GFS lol

Feb 86 does look amazing , shame I was only 2 so didn't remember,  probably dryer in the west but I am sure there will have been deep snow here, although probably not as much as the SE. 

TBH give me a bit more snow on Tuesday, and then a beasterly for a few days and I will be more than satisfied with this winter. Although it is easy to get greedy and want more until March is out.

Fascinating stuff, the negative is relying on the Arctic High for this. 

Yes it was magical. On the Sunday snow grains and grey skies slowly made way for deeper convective showers. By Sunday evening temps were -3c to -4c across central and eastern areas. Loads of snow in a short period from showers into the Monday morning. Then a cursed red weather warning for up to two feet here which never materialised from the low from the SE , a top up  only really , the main snow was the initial stuff from the convective showers. 

Would be happy with a repeat although something more sustainable would be preferred. Still a long way to go to get an easterly in and although the GFS 00z is great , we need others to  back it up.

Key moment here, we need that shortwave to the West of Iceland to disappear so that we get the loop over as per the GFS - 

http://www.meteociel.fr/modeles/ecmwf/runs/2021012900/ECM1-144.GIF

The latest ensemble watch - it's been remarkably consistent with the 5th being the first day a member gets to -10, with the range being the 4th to the 6th. The 7th represents the greatest likelihood of deep cold.

Ok at day 7, difficult to say where it's headed though.

I haven’t looked at the models yet, but judging by the chart above I’d say that would be a ENE or NE flow. Very good for the Pennines and eastern England, dire for the west. 
91,95,2009,2013 were all bone dry for the West Country. If we get an Easterly that’s different. 87 I believe left 39cm here in Helston I didn’t see it unfortunately I was in Aberdeen and we got 2cm of slush......

Lots of even colder rain/drizzle here. I would rather have a slack mild westerly flow than this. never ending cool easterly muck. 

2cm of slush would be an upgrade. 

https://www.wetterzentrale.de/maps/ECMOPEU00_216_1.png 

GEM goes from hero to zero and sinks the high

http://modeles.meteociel.fr/modeles/gem/runs/2021012900/gem-0-228.png?00

 ECM is our new hero 

http://www.meteociel.fr/modeles/ecmwf/runs/2021012900/ECM1-216.GIF?29-12

That's a mean Easterly mean from the GEFS 

http://modeles16.meteociel.fr/modeles/gens/runs/2021012900/gens-31-1-216.png