Mucka

Who are you calling unhinged? Good post Nick. It is not just a matter of impatience though (although that is a part of it) it is seeing things for how they actually are and I think my analysis is fair. Just to be clear though I am not predicting anything other than a cold easterly flow later next week, I am just saying the route there is a much more mundane and slow one than shown yesterday though GFS is a little quicker albeit still with little immediate appeal. I pointed out the reason for that so for me the output if anything is less appealing than yesterday overall rather than better as many seem to think since there will be very limited snow chances on the way to setting up the Easterly (ie not preluded by northerly and/or Northeasterly) for the reasons mentioned. I guess some people are just more excited by high pressure over the UK than others - me, I like a little danger.

Is snow potential not a big part of model watching anymore? Is a charts "worthiness" now only based on how cold the uppers are at 240? I'm sure the real admin's will delete or move if they deem necessary without the pitchfork and torch brigade battering down the doors. People are saying that the output is better today than yesterday, I'm saying it isn't. It is much of a muchness except the cold and snow is more likely delayed as is any retrogression. Yesterdays ECM 12z was much superior than today's yet people can't see it, back to model output analysis school for them me thinks. Yesterdays run had decent snow potential from 168, excellent troughing to the south with a band of heavy snow setting up to move across the south of the UK and massive height rises to the NW meaning the cold was locked in with a probable Greenland high down the road. Okay that is comparing two runs but today's trend has clearly been to shift the pattern East which means the block forming at a lower latitude meaning we are less likely to see a strong Easterly flow, certainly initially because the heights are linked up from the South instead of the North which means less of a trough over Europe and a delay to the colder air coming through. So there ya go, real analysis.

Nobody is saying the Atlantic is about to rush in, it clearly isn't. What they are saying is that any potential deep cold spell is in FI which is correct. They are also saying there is no certainty to how that will pan out. We may get a strong Easterly flow with some undercutting and retrogression later or we may get a UK high that slowly sinks. Either way it looks sure to be mainly chilly with little to no Atlantic influence but I'm not going to ramp over what extrapolated 300+ charts may show. Then again I have a strong bias toward snow rather than bitter cold. If it isn't likely to snow IMBY I would rather it be mild and save on the heating bills.

Yeah I know. I keep screaming, "Mummy mummy can I have ice-cream?" and she always replies, "I'll think about it"

You must be joking. I don't want to wait around for a possible T300+ undercut that might never come. Yesterdays 12z was far superior and look at how heights were shooting up toward Greenland even on yesterdays 240 chart. I'm not saying todays is poor but it aint great and just another jam tomorrow run.

The main models all show quite different charts by 144 for our local - did someone urge caution? I think that is right but also there is no easy way for the Atlantic to get back in so I suspect it will be cool to cold and largely anticyclonic across the UK though the second week of December but we are as likely to see a UK high as Scandi high based on current output. Certainly no definitive signs of countrywide snowfall as yet.

People banging on about potential up north this week and nothing for the South but 12z ensembles have a higher snow risk for the SE of England than the NW of England for Wednesday morning.

They don't go off UKMO 144 raw output though.

NIMBY post. Plenty of warning signs in today's output with the pattern being relentlessly marched East. That could well lead to a stronger block to the NE but how that block aligns with no significant troughing in NW Europe could be quite disappointing, certainly cold but mainly dry and I'm reluctant to rely on T300+ charts for undercutting. I would really like to see the pattern moved back west and a reversal of the signal to flatten things to our West. I can't see any obvious route in for the Atlantic though so I can't see anything other than a cold spell, just that it may well be dry away from the far SE. I would be excited if I lived down there but being in the opposite quadrant I can see snow would be very difficult to come by unless we get some decent troughing in NW/central Europe and that is not currently modelled. So very much a NIMBY post but if the trend continues we could well end up with a UK high with snow very limited for everyone.

Detestable 12z run, frigid and dry away from the SE. Get everything back west!

I can't believe the comments I am reading about the UKMO run. It is just a variation on a theme. We would have blocking develop to the NW and the trough digging into Europe, it is unknown exactly how thins would develop from there but I would put big odds on it not still leading to an Easterly.

Some excellent developments this morning and I am not talking about the GFS fantasy Easterly though I wouldn't kick it out of bed. The tropical wave and ensuing low pressure that has the potential to make or break possible snow chances around this time next week onwards is being programmed to exit to the SE of the UK. NOGAPS split the energy and send a shortwave SE to the SW of the UK while GEM and UKMO have the low exit to the SW of the UK. That will improve our chances a whole lot as it allows a cold NE feed to set in and possible ridging behind, GFS still has the initial pattern further East than the other models and holds the low in situ to our SW while the UKMO has things the furthest West Just to add, the output is showing more of these features developing and GEM sends the next one NE while GFS again holds it in situ. If we are lucky these too will be modified to exit to our SE and, if I were to get really giddy, I might suggest they could end up as channel lows in a cold feed. But I won't, yet.

Plenty of promise even with the spoiler shortwave so wouldn't take much tweaking to see a good Easterly shown again, maybe this evening.

Seems to be and let's hope so but that is not what the GFS Op goes for which is what I was describing, I wasn't making a forecast. Correction to my earlier post. The low is off the SE of the UK and it is the trough that is drilling down through France and central Europe on the UKMO chart. look at difference in pressure over Italy in the 144 charts because GFS has more energy going East and less going South. ECM ls closer to MetO than GFS which is good news so GFS pretty much on its own with the flatter pattern this morning.

GFS and UKMO are miles apart by 144, literally. You must be able to see that? I posted the FI chart to illustrate how GFS is much flatter at 144 with more Atlantic influence thus the insipid FI. Look how MetO has the low sliding into Northern France and the ridging behind, where is the same low on GFS? UKMO has some support from GEM but GEM has a bit of a spoiler low just South of Greenland.

Insipid GFS wanting to flatten everything with only a chance of some brief wintriness for the North in a week or so. UKMO has the low sliding much more and by 144 the GFS and UKMO charts are chalk and cheese. Which will be right if any? http://www.meteociel...44-21.GIF?29-05 http://modeles.meteo...gfs-0-144.png?0 Let's hope it the rather tasty looking UKMO

Fairly emphatic no to a snowy slider from the GFS 00z ensembles anyway. http://modeles.meteo...run=0&runpara=0 Staying cold at the surface though probably, especially to the north with the potential of dragging some cold air back in later. Maybe ECM can deliver?

UKMO 144 perhaps marginally better than GFS but nothing to suggest we have a strong enough block to disrupt the trough enough and keep us on the cold side. NOGAPS and GEM also have weaker blocking to our North and East with the pattern slightly further East so based on this mornings output so far a good wintry slider is looking less likely than yesterday and it is back to looking for prospects further down the line. That said it won't be zonal or mild.

00z not up to much, shortwaves everywhere interrupting the flow of cold uppers and block weaker by 96. Not sure where it will sit in the ensembles but it is reversal of the trend we saw yesterday. Nothing wintry from this in the short term except for the far North of Scotland and high ground Hope is on the mild side of the ensembles and other models are better.

Short ensembles (central UK) (link will show long about 20 minutes from this post) http://modeles.meteo...run=6&runpara=0 The "mild" bump from the 2nd is delayed 24 hours and somewhat flattened from the 00z

That is the last 2 model runs (timewise) that have gone for a slider BOM and GFS 06z I could see hints of it in the overnight output but if it does develop I think it is hats off to Steve Murr who signed off last night hinting that is what he fancied. Hats off to him even if it doesn't come off TBH since the output has reflected the possibility the day after he mentioned it.

This is religion. We don't do confidence, we do faith! I have faith in the blessed BOM and the sacred perturbation 1 of the GFS ensembles, Amen.

BOM is cold throughout at the surface and the uppers never get above -4 for most once we are 48 hours so there will be sleet/snow possibilities throughout with a good slider.

It ain't over yet, not according to BOM anyway that shows a beautiful slider scenario http://modeles.meteo...nh-0-144.png?00 http://modeles.meteo...nh-0-168.png?00 http://modeles.meteo...nh-0-222.png?00

It is not called FI for nothing though, I'm just saying that FI is 120+ and with some tweaks in our favour all is not yet lost. WE need the blocking to hold a little more and force the pattern West and then the low disrupt energy South instead of East unlike UKMO both of which are possible. I'd say a decent slider has about a 1 in 8 chance based on current output but those odds are not hopelessly long. Anyway if it doesn't happen we are only just getting into December so although it would be very disappointing and frustrating we will soon get over it and be ready for the next chase and a white Christmas.