Too good to be true!.......oh....it probably is 

P3 is a highlight if anyone wants some eyecandy.

We usually do not bad here as well as plenty funnel along the M8 corridor towards Glasgow 😅 fingers crossed 🤞🏻 

For London (on MC) the target to beat is 3 members at -15 or below (seen a couple of times in the past week's worth of ensembles) and 16 members in total at -10 or below. 

I think it's the first time since the early January cold spell that we've seen 8 members reach -10 by 180. (The early January cold spell had one run with 29 of the 30 members, plus the op and control, reaching -10. The irony is that -10 wasn't reached at the nearest station which does balloon releases - Herstmonceux only recorded a low of -7.5 at 850).

https://www.xcweather.co.uk/forecast/Braemar 

FWIW the UKMO and GFS are broadly in agreement about the T168 pattern, leaving the GEM a touch isolated unless ECM supports. ICON is more in line with GFS/UKMO than GEM but is a bit bland about it. It's not really meaningful but at T120 the GEM is currently tied for second with UKMO and as usual behind ECM - I'd rather see how it verifies with blocking patterns over Scandi and the Arctic but it does confirm it's verifying well in general and can't entirely be disregarded. 

Looking at the GFS again one nice thing is it's cold enough for wintry stuff in Scotland in the reliable - T78:-

With the snow risk extending south as the cold air pushes down, this being early FI but a reasonably plausible setup albeit probably too snowy:-

UKMO isn't as cold or wintry  but even here it has higher ground snow for Scotland from T90 or so and more widespread wintry precip as it too sinks the colder air south:-

I think *if* we're still seeing similar charts to the initial cold push currently at T156 this time tomorrow or maybe Wednesday we can be a bit more confident that bit is fairly likely (assuming ens support) but I suspect how the pattern evolves from there with the jet looking to stay active and maybe move back further north is going to take a while longer to resolve or at least coalesce around a broad evolution.  

Edit: I assume where people are talking about the GEFS it's a short set on another site? 

It been for over a week now some members going for -15C without giving up.  12z for my area ensembles now the mean dropped to -6C to -7C so another 5C needed to drop to -12c to guarantee no LESS COLD temperatures, I worry a lot about those nasty less cold temperatures 1 to 4C, that will not give snowfall, possible cold rain, or if snow won't settled, won't be powdery and no cold nights.

If that gets too much for you, pop down here for some cold drizzle! 👌

https://www.xcweather.co.uk/forecast/leysdown 

(On a more serious note, with all the snow that the mountains have had, and are forecast to have, presumably that means our chances of seeing some snow patches last through the year are higher than usual?)

Yes, the ensemble mean 850mb temperature goes down to around -7 for SE England and stays there, compared to -5 at beat on earlier runs.

At least for those of us in the south, with an easterly a temperature of 1C will generally give settling snow. That is because the relatively short sea track means the air will usually be fairly dry when it reaches us, with the "wet bulb" temperature of the air being depressed by a couple of degrees compared to the standard "dry bulb" temperature.

(The wet bulb temperature is the temperature experienced by a moist object - such as a snowflake - because of the cooling effect of evaporation, and so long as it is below zero there will be no melting. It lies somewhere between the dry bulb temperature and the dewpoint. It's very useful, but I believe most automatic weather stations don't report it, though I believe you can work it out if you know the dry bulb temperature and either the dewpoint or the relative humidity.) 

It seems almost to be a rule that in the lead-up to any cold spell there has to be a sizeable wobble point. Fingers crossed that that will have been the last. 

I think so, at elevation at least, although there may be a period of thaw with heavy rain before the colder air moves in. Our last snow piles are slowly shrinking. 

More generally the swinging to and fro in the details continue in the output but the now strong trend for an easterly is clear. Having said that things can and have gone “wrong” in the last at this timescale and I have noticed in the last few days the 00z output is more Atlantic biased and the 12z more Scandi-biased so I wouldn’t be surprised to see a “wobble” again of some sort in the morning.

It is certainly interesting viewing (apart from the two days of rain coming up here in NE Scotland). I will share your drizzle no doubt at times in the coming days and for variety it may be heavy drizzle at times and light drizzle at others.

https://www.theweatheroutlook.com/charts/ecm/12_168_mslp500.png 

The ECM and GFS ops now look remarkably similar around the 168 hr mark. The odds on a cold spell must surely be increasing, severity of which TBC. 

I was literally just coming on to mention the swing back in favour of a stronger Block, and this exact point. It does seem to have been the case and I'm pretty sure it was also evident last winter too.

Yes thanks and I do understand too just with the global warming issue we just need a lower 850s to make sure it stay subzero day temps and sufficient cold nights.  Hope by tomorrow to see further drop on the mean.

This is one of the few things I don't agree with you with on TWO 🙂 It's something you frequently bring up about this S.E. bias. I don't see it as we have all been enjoying the Docs snow reports and images and others  the other week when there was snow about. In fact there are only a few of us in what I more correctly call the South of East Anglia in which I include Suffolk, Essex and Kent. I'm possibly the only one in Essex which has a population of 2 million! At least you have had snow. It is hardly surprising that we do concentrate on our own areas, as we all do. The fact that we used to get a lot of snow and have had virtually none for 10 years could be why. You yourself in this very post just said "What many in the SE/S want isn't that good for MBY, so I'm not that fussed." which is close to the ultimate IMBYsm 🙂

Is that correct without exception? 

Showing it's FI I guess you can see gradual divergence from T120 with differing takes on the atlantic and how that plays with the blocking to our east and north. ECM looks to be one of those near jackpot runs for some folks although very much in the high risk/high reward category. Will have to see if the precip charts are showing (cold) rain IMBY or something a bit more interesting but there's 2 LPs that would at least bring snow for some folks and the extended looks cold too. 

The GEFS were much as expected I think - still a lot of scatter but maybe better grouping around or below the -5 line down here (bit colder up north). Encouraging but I could copy/paste from comments on earlier encouraging GEFS where the following days runs nudged back to less encouraging. 

MOGREPs aren't overly nice for London, being split between colder air moving in around 25/26th and it staying average or a touch above. Again further north it's a much better picture. 

So decent as it goes but I think we're a day or two away from agreement on whether the T120 cold push establishes properly or the atlantic pushes through too much. If I had to guess I'd say the former is more likely as it stands but not convincingly so.