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I think too many have already become desensitised to what constitutes a 'fantastic chart' and the seasonal ailment of this thread (which is irrationally mood driven anyway by the more average synoptic charts that are customarily on offer) has taken on a latest variant of becoming superimposed and twisted on the absurd semantic that 'merely' only UK Tundra conditions are being shown and not the Canadian variety. Truly, if you cannot exercise self control in front of your lap-top by the smorgasbord of dessicating cold solutions evident on NWP, especially as we are heading right into meteorological Spring, then its maybe best that a different form of self torture is considered to spare those who take a more considered perspective. This has nothing to do with any regional bias (coming from a part of the country that relies on these increasingly rare sort of synoptic to get a snow fix) its to do with the usual fascination I have for sitting back and marvelling at watching a pattern like this unfold in the greater macro scale. If/when it snows at home, I will be less inclined to spend spare time waiting for when it is next going to snow, or when its going to end - but instead getting out, having fresh air, exercise and enjoying it. And then, when the snow and ice is over, it will be a case of seeing how the patterns evolve through Spring and into Summer - looking for the best that can be on offer for this Island, whose micro climate is fickle, elusive and overly too mobile to the sort of sustained blocked patterns that can be the deeply cold derivative as upcoming next week, or depictive of deep Azure blue skies, sunshine and warmth of the summer. Get used to this reality - it will always be thus

I wish you guys could see the precip charts on the EC. Serious disruption Tues and Wed on this run across swathes of the country.

Another great day of model output with no concerns from me with what is shown. 2 points First is that the worst model output that we have seen today and the last few days is far better than the best output that we have seen for many a year. So don't be concerned with operational variations. The second is that normally any shortwaves scuppers any cold spell, but in this case I welcome shortwaves because once that cold air is embedded ( and movement will always be west of the general pattern), then we have shortwave snow making machines on our hands. The more shortwaves the better as far as I am concerned because the large Greenland block will keep us embedded in deep cold.... Just enjoy the output and whatever it brings.

Anybody fretting about whether it's marginal, it's not even close.

Ah those were the days, 'real' snow depths not your 1-3 cm and traffic chaos like now!

Wow, some of you are like bloody toddlers. Either grow up fast or don't expect to be able to post in here for much longer, it's ridiculous.

Looking, or rather skimming through the last x pages from late afternoon, reiterates why I do not spend too much time in here. Some of you for goodness sake have a walk outside, watch the tellie, talk to a real person away from the pc. What you are watching is the weather models trying and slowly but surely, as they always do, come to a concensus about what is happening. Quite why folk worry about T+240 and beyond when most predictions by the models at that range are highly prone to change is beyond me. Deep cold is 85-90% likely to occur, it has never really been sensibly predicted by any of the more serious posters assessing the various outputs to occur before 23-25 February. That was two weeks out. Now within a week of the second date that is being refined to more like 25-26, so what? Get a grip and become realistic, they are models created by humans, are you perfect? end of jh rant. here is the latest link to NOAA 500 mb anomaly charts. This level, approximately 18,000 ft is far easier to predict than the surface, these are mean charts, but they are about 70-75% close to what occurs in about 80% of cases. Yes they are wrong at times but not often. http://www.cpc.noaa.gov/products/predictions/610day/500mb.php To me, using them every day for about 7 years and during the winter for 10 years or so I cannot recall seeing charts showing any more solid northern blocking for the time scale they are showing, this for at least 3-4 days. That includes the deep cold much of the country had in late Novemeber-December 2010.

Also.. Please remember that there are loads of unseasoned folks reading the thread so whilst your tongue in cheek comment might register with frequent visitors, it may well be completely baffling to most. It’s easy to think that the board is just the same 10-15 people reading and posting but there are 500+ on tonight. Don’t be a dick in front of 500 people, I guess is my message.

It baffles me how some are managing to find negatives in the current output. It is not being delayed, no idea where you're getting that from. If you can't enjoy the current output then you'll never enjoy any winter synoptic set up.

All this fuss about downgrades - 'chill' out ! Looking at two runs 24 hrs apart so examine the same time stamp - from last night's 12z to tonight with a helpful Polar Bear diagram included. As you can see the Polar Bear still on course to arrive, just a slightly less ferocious looking bear this evening..

I've had a great idea, we could make some other threads and areas on the forum for people to discuss all sorts of other topics that are accessible with just a couple of clicks, then this thread can be kept to just model discussion? Oh wait....

+168 hrs ECM:The beast cometh!

The anomaly charts continue to support the overall pattern of northern blocking with lower heights south of this. The 8-14 NOAA is as good for cold as I can remember for a good many years. How cold, how snowy then much too far ahead and these charts are not for that purpose. The synoptic models will give some idea but not this far out. T+72 or so for a GENERAL idea, T+12 for detail. http://www.cpc.noaa.gov/products/predictions/814day/500mb.php The ECMWF-GFS version also goes along with the NOAA advice http://mp1.met.psu.edu/~fxg1/ECMWF_0z/hgtcomp.html

so... the beast awakens at +48hrs and mutates into a snow-making monster local authorities are organising replacement bus services-

This will not be a dry easterly with scattered snow showers as per ukmo 120-144 - there will be non stop snow in the East & SE , NE up to about Newcastle & this will push across England & become more broken / spread - so yes if you live in the west It wont be quite as good to start with. As mentioned now by me / Nick L etc etc this is lake effect snow. 1 day of perfect allignment will bring ~20-40 cms of snow in the best areas - up to 10 on average- The flow looks to be sustained 2-4 day poss longer.... do the maths....

I think some are worrying about small features that pop up in the models, which, physically won’t have much effect on the general well documented/agreed on momentum westwards of the deep cold as @Catacol has already highlighted. A small surface feature cannot alter the upper pattern and the jet, it’s normally the upper pattern and associated jet that dictates the movement of surface features. The movement westwards of the deep cold is being driven partly/mostly by the remnants of the daughter vortex that formed from the split of the SPV by the SSW beginning of last week, which dropped into NE Europe / NW Russia and will now move west over Europe and is coupled with deep cold pool moving west in the troposphere. This weakening strat vortex can be seen on the 2PVU loop below (in blue) on GFS tropopause (where trop meets strat) pressure charts, dropping south over NE Europe then moving west. This is in turn causing the jet stream to push SW across Europe – helping pull the cold air west and southwest. A small surface low or ‘shortwave’ as some like to call it won’t stop this momentum. <--- click to animate

Well my simplistic UK forecast on the forthcoming brutal cold would be..... Cloudy with the chance of Penguins.

I wish people would stop posting these inaccurate charts, they're utter nonsense. I know they're the only freely available EC snow depths but they're utter tosh.

Another thing to consider is that dry snow puts down more than wet snow for the same liquid equivalent. With wet snow it's typically 10:1, dry snow can be around 30:1.

I think I'm becoming a tad desensitized to the outputs now.....let's look at the 12z ECM.......hmm, lots of snow forecast for next week?....how much?.....12 inches?....just 12 inches?......T850's only -14C?.......boring!.........change the record....seen it all before

You know it's a severe cold spell when the 510 dam 1000-500mb thickness line has moved over the UK! Rare for it to happen. As the deep cold advection eventually waters down later next week on the 06z GFS op, the run offers a reload of very deep cold air from Barents Sea area maybe in the offing first weekend of March, which collides with Atlantic lows trundling across France - BOOM Oh dear, think I'm losing all kind of forecaster sensibility and sound thinking looking at these GFS charts in FI!

goodness gracious, pages and pages of ridicuously OTT ramps....this is really on a knife edge folks, just a small variation will change the weather pattern totally....I mean for example if you take the GFS00z run and then rotate your computer screen clockwise 90 degrees you'll quickly notice the isobar lines change direction and you get the mother of all southerly plumes with temps in the mid 80's......I'll fetch me coat (thermally insulated I might add as I'm going to need it for the next two weeks) notice to mildies, doing this is the only way you're going to see southerlies for the next few weeks.....lol (I do believe I have ramped again, that's twice in the last 12 hours........I need a lie down)

My word, some of you lot really are the most downbeat, negative, miserable bunch. Why do you keep expecting every run to be perfect? This is the 18z for starters, and it’s still out of this world good. The mild(er) uppers in the south would likely have little effect on the nature of the precipitation, it would likely be all snow, after the entrenched cold. A reminder of what the chart and the uppers looked like during one of the biggest snowfalls for the SW of the 20th century... Look familliar?

Minor feature develops.. Are a sure cause for a major inflow.. As exactions of flow are aligned.. Its like farting in the bath.. Smells at first...but then the bubbles clear.. Horrid way 2 relay it... but simple-..and honest!!!!!

Honestly, what are people on about with the cold being delayed? The serious cold was and still is expected to arrive Sunday/Monday. There are a few wobbles either way at times but it's not being delayed.

Well I might start acting all out of character and posting positive things ? You won't be able to make sly digs at my expense... I'll start as I mean to go on... Good output this morning.

That's fine - go do your research: I've done mine. For length this will likely outlast 87, be a bit less cold but quite possibly more snowy. It looks as cold in uppers as 47 though not as long.... but snow potential matches. Definitely more impactive than 91 or 96, and in my book an improvement on 10 (though we will only be able to argue that after the event.) Nothing can touch the longevity of the 63 winter - but taking snap shots from that incredible season what we have approaching is of similar intensity, even though spring is on the doorstep and will cut it short. I'll hold to the claims. I think the next 2 weeks could go down in the history books as one of those special events. A ramp? Yes - but take a look at the output and the signals. All irrelevant now of course cos it hasn't happened yet - but after the event we can review. :-)

I really don't understand all the excitement. A cold snap that looks like it will be all over by mid-April....

As Steve has correctly said in an earlier post - we will need until Thursday before we can be 100% certain that the cold, as modelled, is going to hit. But I think we are 90% there, and my fears overly a potential southerly track are all but gone. There's barely a sniff of a southerly trajectory in any of the output, and as the models resolve the collapse of the Canadian vortex the HP is being moved into the most favourable of all positions. I don't want to say - "unbelievable" - yet again... but somehow it does need to be said. BBC at 0750 did something I don't think I have ever seen before, and that was put up a graphic for next Tuesday illustrating daytime max temps at below freezing. 7 days away? Every model in line, MetO in line and all we are now left to talk about is snow depth. Concerns over power, infrastructure, the old/homeless and general safety become real in this circumstance now. I hope the Met don't wait too long to put warnings out (its amazing how many people here at work have looked at me strangely when I said it was going to be extremely cold and possibly snow next week) and that everyone enjoys what comes AND tries to help those who will need it. Sleeping rough under -15 850s and heavy snow is not a combination to celebrate. But on the positive side - wow. Back end of next week for the SW to see real fun as per this chart or this one or this one (so many to choose from!!) but starting Sunday I will sit back and enjoy watching images of the east coast come under fire, and prepare for the best spell of weather since 1991/96 and quite possibly a spell that will outdo both of those, outdo 1987 for longevity and match 47/63 for severity. Big claims - but the model runs support such interpretation.

No worries, we wouldn't want that.......tell you what, let's play a game.....I start counting 1, 2, 3 up to 100 and when I guess the right number of cm's, just say "STOP"

Latest NMM 1km resolution to Sunday afternoon

But its a dry easterly !! Deep deep snow suggested on ECM again tonight !

Courtesy of Ventrice over at WSI - ECM temp anomalies for next week. Gulp. If my reading of shades of pink is correct, that's an anomaly of -5 for the south of England. And via Masiello and Alicia Bentley - a stark representation of channel low style synoptics running underneath a very vigorous and cold 850 easterly airstream. Dry? I doubt it.

NMM 1km resi

They should have stuck with the Met Office instead of penny pinching . I think it’s outrageous that the national broadcaster turned its back on the UKMO. PS the new graphics are dire and the BBC weather team must feel like their polishing a txrd trying to big them up as innovative !

So with trepidation I opened the models in following sequence. UKMO - check.....lovely bitter easterly GFS - check.....lovely bitter cold easterly with lots of snow to come and goes on and on with easterly reload at the end.....Chio? ECM - hmmm - not as clean.....quick check the uppers....oh boy, disturbed with widespread -12 uppers......snow snow snow GEM - safety in numbers....awesome Phew.... BFTP

That;s what you call a direct hit! Bewildering.

1001, 1002, 1003..... BFTP

The mean is further North than the OP run was, Can we stop throwing the toys around, now? Even if the OP came off exactly as modelled it'd still be pretty damn notable.

Definitely a few posts in here tonight that I’d probably call attention seeking at best and trolling at worst. I know in this day and age Amazon prime can usually provide a unicorn at a days notice, and we are all a bit spoiled with the ‘I want it right now’ culture, it’s worth remembering that although there are some timing alterations, you can’t track the cold delivery and we are at the mercy of far bigger atmospheric things in play. If we were talking about t+240’s then of course I would be taking a totally different stance but we aren’t. Just... be cool!

Really? People are worrying about "less cold uppers" up to a staggeringly warm -7c? Come on people, I mean seriously! -7c uppers is more than enough to produce snowfall. The ECM is an absolute snowfest but just about the entire country with some very significant snowfalls for many. We're getting there, we're getting close, stop worrying and holding onto every single model run as if it's the truth. The Easterly begins at 42hrs.

There really is no pleasing some people, is there? 12z GFS continues to be incredible, UKMO is a solid 10/10 for me, can't wait to see the GFS We're about to see the snowiest period for possibly years.

What exactly is the problem here... I’m struggling little bit of inter run variation and guess what we still end up in the freezer. Deary me.. unless you’re from Iceland, nobody can complain at the 12z output.

I made a GIF, see for yourself, with the predicted ammount of snow in this run. It starts at +126h.

I think most of the country would be happy with the 13th member by the 3rd March Edited to include graph

I think people need to calm down and not react to a run which is still within a borad envelope regarding how the cold to our east will interact as it tracks towards the UK. To emphasise this, the GEFS are further north with the high compared to the 06z suite with a much larger cold pool pushing in. That is a stunning mean, again there will be variation run to run.

I think I'm with @frosty ground on this one. A surface feature like this is unlikely to overrun a pattern that is being driven by much larger forces. I was a bit concerned a few days ago by thoughts that the warming might actually drive the whole storm track too far south - but such suggestions have moderated. Frictional input from layers above is holding the cold to a trajectory that works for us - ECM strat 150hpa here for 192h and nothing here to suggest that the track is going to drag down towards Spain. We'll wait and see if that ECM cluster for a mid atlantic high returns - but frankly it feels somewhat counter intuitive to the current setup.

Morning all, what wonderful winter charts we have. Pick for me is the two from UKMO. The model rock solid route to prolonged cold and now in the reliable time span. The human input in the latest fax chart , this one for Friday shows the increasing North Scandinavian heights continue to gather a pace as the week progresses with its extended strong ridge pushing well into the Eastern Atlantic. Now we also see the depth of coldness likely with the plotted 528 and 510 dam lines indicated. For snow watches its that area between Latvia and Denmark that we have to look for trough development in the increasing depth of cold as it advects towards the British Isles. Think late Sunday and into early next week looks good for convective snow showers to move across your part of the world. Beyond that retrogression of the high with frontal attack from the SW ? Who knows...just enjoy and await the Eastern delights in store !! C

I'm baffled. Not by the model output but by the reaction to it. Great runs once again.

The lack of comment on the UKMO is rather ironic, it looks excellent yet simply because the GFS has more data available to the public everybody starts showing signs of panic on-setting. UKMO probably the best out of all models.