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UKMO better, UKMO worse...GFS better, GFS worse... Guys, how about we stop overanalysing minute details in every run, or at the very least wait until the entire run is out? The last 30-45 minutes of posts are so contradictory it's daft.

Broad scale, the GEFS is more likely to be the way December pans out. There may be timing issues here though as the ducks are not quite yet lined up. I'm looking for tropical convective wave to develop east of Indonesia and an attendant +ve mountain torque to develop as the necessary triggers to a truly cold pattern to embed. That's still a little way off just yet, so the choreography of the 06z GFS may be a little fast. My position 1st week of December would be for the UK in a mean trough with a broadly north of west flow, temps below average. The more extreme version advertised by the GFS 06z is plausible given the background drivers - extremely weak polar westerlies, massive disconnect between angular momentum and ENSO status, so I would not be keen to discount it, rather have it on my side as a second choice (particularly if you've already hedged this way some time ago).

Briefly ignoring all aspects of any meteorology, got to say that 06Z GFS run is worth saving and salivating over for the rest of the day, especially after the relentless dross of 12 months ago!... However, and back to reality. The differences between the GFS and the ECM are significant and, as Glacier Point, highlights especially for the UK and NW Europe in general in roughly a weeks time they are about as opposite as can be. Examination of the EC Clusters at T+192hr (Fri 2nd Dec) show that just 10 members, out of the usual 51 members, show something similar to that of the GFS evolution, ie; a marked region of blocking and with more of a marked trough over the UK and NW Europe to allow for a possible cold N or NW'ly flow. Clearly 10 out of 51 is a minority and, for now at least, the ECMWF just isn't buying the GFS evolution, all directly related to the up-stream developments just off the eastern seaboard and/or Newfoundland region in roughly a weeks time. It is safe to say that no official forecasts will be going with what the GFS is showing just yet, primarily because of the distinct lack of connection between the GFS and the ECMWF and not only that we are still talking about a possible 'event' that is 6 or 7 days away, a long time no matter whether consistency is good or not. A case of just sitting and waiting to see if the consistency develops (and for us cold fans hoping on this occasions the GFS is picking up the correct evolution) especially if is there is then cross-model agreement with the EC and GFS as, to an extent, one of these models is likely to be more right than wrong. There is always a possibility both could be wrong and a different evolution occurs, but I can't see that now. Matt. NB: Winter forecast from myself and Tony (Lorenzo) likely to be issued before the end of the week, stay tuned!...

worth noting we now have both North American ops singing the same tune here..

Seems to me the reasons not to go cold are being removed one by one... Compare Tuesday's week 2 forecast for upper level velocity potential in the tropics and today's.. You'll get some idea of the pace of change here - not fast, but the steady trend is to shift the convective wave associated with this towards the Maritime continent. Trend in GFS modelling a reflection of this, mid Atlantic ridge and developing North Pacific ridge. Notably EC modelling has been much slower with this wave, and more broadly convective wave passage through the Maritimes shows lower skill. So expect poor model reliability to get worse. GEFS and GEM modelling of the stratosphere is different to EPS, although broad agreement on a Canadian Warming and slight rotation of the stratospheric ridge on an anticlockwise rotation towards Greenland. GFS is a good representation of this, although on the weak side for this run, but the prospects of a squeeze on the upper vortex from both sides of the Pole from Atlantic and Pacific sides looks like a long term trend here. Where that takes us.. should see increasing propensity for tropospheric ridge across the polar region, and increasing meridionality in the Atlantic sector. Latest EPS very unconvincing in its anomaly fields being very weak signature across its mean with the exception of the North Pacific ridge.

Whether it is right or not, we haven't seen a run like this for years. First this which becomes this and finally this A northerly, then a channel low, then a north-easterly - is that the meteorological equivalent of a "full house"?

Some of these post make no sense..... Just one liners that add absolutely nothing to the thread......

At the risk of appearing 'boring' - its the same caution watchword from me as per the last couple of weeks. Its well known that tropical convective modelling is especially unreliable generally across the models beyond about 5 days. On that basis I don't think we can apportion a 'correct' solution here - its very much a watching brief. That said ( and is the case at all times) intra-seasonal and re-cyclical timeline factors are principle assets in attempting to eschew when/how tropical and extra tropical phenomena might evolve, and in turn influence NWP solutions. Its on that basis that intuitive guidance, as being applied on these pages, is certainly reasonable and highly valuable in terms of suggesting another return to the tropical signal in the Maritimes - the rinse and repeat forcing that has frame-worked the wider weather patterns since the later part of the summer. It is very much the return to this signal, that would boost atmospheric angular momentum and augment the process for amplification and higher latitude height rises in tandem with an unstable vortex. However, the precise timing of this, in my opinion, is actually becoming increasingly important for that those looking for seasonal cold and white stuff (which naturally includes myself) and will want it to occur in very close symmetry with maximum stratospheric destabilisation. A downside risk evolves according to any degree of 'failure' here. In this respect, there cannot be excess delay to the tropical signal, and there cannot afford to be any further shortfall in stratospheric weakness forecasts.. So whilst the latest ECM suite (s)may currently appear 'wrong' ( after all, it isn't showing what people like) it remains very wise to acknowledge that it is a (provisional) warning of what can happen if the types of shortfall mentioned verify. Whilst a favourable stand-off has existed between weak Nina ocean and atmospheric circulation signal, the trend heading into winter (desirably for those wanting cold) is one where the atmospheric circulation is best one of angular momentum inching higher within the parameters allowed by ENSO, not just to capitalise on early stratospheric weakness, but to bolster longer term amplification feedbacks that encompass Eurasian snow cover albedo. 2012 has already been cited as a good example in a recent post where froth and fervour to greet the winter season turned to fast frustration when seemingly 'little could go wrong' in the model world. It did come right from Jan 2013, but it was a virtuous +AAM cycle, as driven by amplifying tropical and extra tropical phenomenon alongside stratospheric weakness related to SIA that enabled this. ...It was also a stutter in this cycle that initially scuppered it... Delays and shortfalls - then the hallowed Pacific Ridge will not sustain as a poleward feature (as part of a cross-polar ridge pattern for sympathetic downstream higher latitude height rises) and will entail a typical Pacific winter Nina like pattern at mid latitudes with early winter reliance on some cold zonality and brief arctic topplers before, potentially, the Atlantic jet increasingly flattens out as maximum stratospheric weakness is not utilised and seasonal wavelengths change further to couple the Annular mode 'unfavourably'. Its to be emphasised here that this is a low risk scenario at present. However, if traction increases to consolidate an eastwards signal in the tropics as consensus modelling, there are continued signs to show that the Pacific favours a ENSO neutral with a +AAM tinge (a winter such as 78/79 is a good parallel here) then stratospheric weakness will be utilised with the Pacific ridge very much a friend in terms of being part of a cross polar stratospheric induced ridge - that is the beginning of a period for snow and ice. The latter constitutes a deliberate ramp, but you get the picture. The former represents something less exciting - but whatever the models, the professional consensus etc may suggest - it cannot (yet) be dismissed.

Looking at the last 24hrs whats changed ? More runs needed Patience running thin today I think we are still waiting for GFS 'epic fail'. UKMO was bloody disappointing today, 12Z was a joke ECM is on the follow me your b***** I'm top dog and GFS is moving that way. More shortwave spoilers have been found, t*ss**ers* Models are struggling at T120 so lets post some T240 charts Tamara, keeps cautious optimism METO further outlook/forecasts now suck because they look poor UKMO sucks and has got a real good kicking today from members for not showing what we want. Of course its the worse model ever. The GFS has found another shortwave to spoil the outlook. .......Why GFS why ! , give us a break stop finding shortwaves in the wrong place ECM having none of it. It has been pretty consistent compared to the fickle gfs. Pub run we want the ECM to 'flip over' --------- So ECM won the day for consistency, UKMO has been put in the hospital and short waves have been really pesky today. For cold lovers its 3/10 day hence why only 20 pages posted On a positive its still Autumn lots to play for

Good morning all. Looking at the output so far this morning it seems we are firming up on that Northerly outbreak with UKMO primed at 144 for the trough to dig South with decent upstream amplification which should accentuate any ensuing Northerly flow. Beside it the slightly faster and flatter GFS 00z And that is encouraging given this GFS 00z at 192 So we could be seeing the very quick development of a cold spell here and a better insight into recent MetO thinking re early Dec cold, It will be hard to predict how cold uppers will be as it will depend on exactly how the trough develops and if we get any spoiler shortwaves develop on its Western flank cutting off the Northerly flow or developing a West based -NAO. That said, if we stay on the cold side of any embedded troughs it could also be potentially quite snowy. Caveat being there is a fine line between cold rain and heavy snow in such situations - all that is for 72 hours and less if we actually get the Northerly to verify though really - getting ahead of myself again. Very exciting output so far so let's hope ECM comes on board. Edit. Stunning GEM with a direct hit and WAA into the heart of Greenland, hope this is our ultimate destination. That would be very cold indeed. Remember GEM massively under-does negative 850's GFS FI looks primed to give us a Scandi high and Easterly But instead drives a trough down from the Arctic and ends very blocked which while not to be taken seriously is much more encouraging than seeing deepest FI return to climatology.

Given that EC's 00z ENS median T2 for central-southern England sits anywhere from 0 to barely +6C from 28/11 to 4/12, there's really not much disagreement on broad bias towards somewhat below avg temperatures in either that model or GFS (EC showing a few markedly colder members too). However, spread in EPS fields for MSLP remains very marked by early Dec, hence caution required re just how we sit re extremes of temperature/ppn/wind into that period. I know it's stating the obvious, but at that range the deterministic runs are not to be read in isolation (for any model) without examination of their respective ensembles/postage stamps/clusters.

Certain people on this forum infuriate me, it's one run and it's not even backtracked just because it doesn't show the ridiculous snowmaggedon from the 06z doesn't mean it's 'game over' Please get some perspective.

The winter forecast for 2016/17 has been released, and is named 'A Winter Of Wildcards' There are two versions to view: Full Winter Forecast 2016/17 Winter Forecast Summary The forecast this year has been written by Tony Wells (Lorenzo) and Matt Hugo, and as you'll see it's an immense amount of work that they've put in to put it all together, so a massive thanks to them both for doing this. A change this year is that we're going to be issuing updates to the forecast, which will be published after mid-month throughout the winter, to look at how things are progressing, and detailing any changes which may have a knock on effect across the rest of the season. Here's to a fun winter!

Watch the ECM flip now to a belting northerly just to clear things up! Sometimes wish I didn't love snow so much, it's too bloody stressful! COME ON ECM

Indeed, one post says good run, the next one bad. Some should wait until it is clear what has happened before posting.

Morning- upgrades all around today - GEM /UKMO in the ballpark for the 30th now- GFS still solid ! S

Cracking 06z, snow for everyone and it even ends in an easterly. Incidentally, Tokyo had its first November snow in 54 years http://www.bbc.co.uk/news/world-asia-38088036 That's 1962......

Lack of cross-model consistency (even in the semi reliable) and, thereafter, a messy solution 144hrs onwards makes me doubt the surety of any upcoming cold shot (or any other shot) in the short term but there's one thing I know for certain, the words 'upgrade', 'potential' and 'blocking' were in very short supply at any point last year and those same words have aleady been bandied about quite a bit on this thread as we head towards winter proper. Also, there are still any number of positive synoptics (solar slumber, disorganised PV, Siberian warming, sea ice levels, advancing Eurasian snow cover) in place to make this year far less disappointing than the boring sludge we've endured over recent times. Although all models appear to have their own strengths and weaknesses, I'm as yet unconvinced by the latest ECM updates which appear to have over compensated for its propensity to exagerate Atlantic amplification (am reluctant to recall THAT notorious occasion but there have been other unforgivable teases too). What I have more confidence in, is the quality of analysis and knowledge on this forum, and I'm grateful to all those characters who share their time and expertise so generously....giving followers like me a welcome weather insight, unavailable anywhere else. Keep it up (you know who you are), we don't all have the knowledge to post on here with confidence but that doesn't mean we can't enjoy the ride.

All 12z suite sees a considerable move to ECM 00z solution - UKMO + GEM are pretty much all the way, GFS is hanging on however has moved to ECM- If the ECM verifies it will be the second time in 10 days the GFS has gone for some form of Greenland block ( & ENS ) & then reverted to ECM around the 144 mark- very frustrating - not least of all because the GFS strat forecasting & zonal mean outlooks were underpinning It all & if we move to the ECM solution the 60N zonal mean will upspike TOWARDS normal .. not great...

Who can be confident in the longer term? On the 4th of December, we are getting Gales, mild south westerlies and a chilly high all in the same day

Things looking good to me at +66 This time 6 years ago

Great post, very funny. I hope you'll be doing this nightly throughout the winter.

Been trying to type up my winter LRF but have a chest infection and I'm well 'under the weather' pardon the pun. But my Nov LRF favoured pressure build to our W / NW at last part of the month into Dec and I favour a flow N of West as a general theme [this will entail periods of LPs diving down on NW/SE access which at times will bring winds from varying Northerly quadrant angles. Re early Dec As GP alludes to timing is of essence but I will put my hand up too and say ECM has got this wrong in FI and GFS is sniffing the right direction. I also however don't see an arctic lock out.....at this early stage of winter...but arctic outbreaks, relaxation, reload etc. Now ECM make a chump out of me.....well I don't need ECM to do that BFTP

Those saying its game over..it isn't..The game doesn't even begin until Dec 1st..this was followed by a stonking 6z and plenty of Ensemble support so let's just keep calm, it's all to play for and the models dont look anything like as mild as last year..much more seasonal level playing field!

Looks like they saw a similar cold anomaly in January - holy grail synoptics. T 850 Z500 Strong wave 2, pre SSW split, in evidence there. An edit to keep to current topic. JMA progressing the pattern shown last week - gives a bit more confidence and continuity.

I'm trying to summarise 20 pages and hope I have shown a fair reflection of members thoughts. .Tomorrow will UKMO stay in hospital, go on life support or 'flip 'and be the 'best model', the 12Z did get a horrible beating today

Holding steady out to 18h!!!

You have to laugh or not as the case maybe! Firstly we want rid of the UKMO output, its beyond redemption. The ECM is passable because the overall pattern might deliver a Scandi high, the shortwave near Iceland at T192hrs was just so typical of the last few days, its that vile little blob which stops better WAA north. The GFS without the spoiler shortwave which deepens would have been very good. I think its clear that the upstream pattern in the USA is causing a lot of problems because this downstream effects the phasing/movement of shortwaves in the Atlantic. Overall my mood has lightened somewhat after the ECM didn't back the UKMO however we do seem to be chasing shadows with the outputs seemingly determined to wring every last ounce of drama over delivering anything of interest.

That's not what the charts show.. These emotionally driven responses to what is basically a forecast is bewildering. UKM stops on the last day of November, Low pressure riding over a high and moving east will bring a northwesterly in it's wake. But looking at such detail at such range is basically a fools errand.

Honestly people put too much credence in the METO further outlook/forecasts, this is meant in no disrespect but they are wrong just as much as they are right! The tipping point with this setup is coming soon this is for certain, with it coming into semi-reliable timeframe, I trust the GFS more re: energy in the atlantic and shortwaves but we've seen it has a bit of a tendency to build pressure over zealously. In summary, I have no clue and this post is about as much use as a chocolate teapot.

Yes very interesting Model watching ,good run so fa r on GFS , but more runs needed to firm up and settle our Nerves .No joy of course on ecm run but i would expect going by what met office are hinting at for about ten days time i would hope to see Ecm throw out some stella runs from about saturday onwards .I,m going to firmly keep an eye on 168 hrs after all thats a week of weather ,From my experience if its out there [cold and snow ]it will probably be hinted at in main models then get snatched from us then emerge again with Met office very confident ,it should all come together ,and hopefully we can then start humming that song ,[let it snow let it snow let it snow ] so today a good run from GFS , lets see what those unseen bits of data that MET OFF use, is saying in outlook and eagerly awaited tonights runs , But gang stay calm ,we are still not in official winter yet cheers ,

The key difference (not for the first time) is the difference between how GFS and ECM model Low Pressure coming off Newfoundland. On both the 0z and now 06z runs the GFS separates the feature from the trough over Greenland, opening up the vital gap for the Atlantic High to ridge northwards. GEM supports this evolution. ECM start with promise, but then has the Newfoundland Low merge back with the Greenland trough which blocks the High. JMA supports the ECM evolution. We need to see ECM move towards GFS and GEM on this. GFS (both 0z and 06z): T144 T168 T192 ECM 0z: T144 T168 T192

The Gem 00z is how December should start! It's what coldies deserve

John Hammond is a brilliant forecaster...one of the best the BBC have at the moment in my very honest opinion.

lol....quality post..........my NW model thread bingo card has been filled several times over having read and digested today's pages of posts........so to sum up, after next week no one, and no model has got an absolute clue what will happen....no surprises there, so let's see what fairy tales the 18z GFS comes up with shortly....should be interesting

Here it comes, the 12Z we've all been waiting for...Is Snowmageddon incoming or not?

Time for cautious optimism methinks? The ECM does indeed outperform the GFS; but, at 6-7 days hence, I wouldn't put too much faith in either of them, as regards detailed evolutions. Though a transition to generally colder conditions looks to be almost beyond dispute, the details will remain up in the air... Will the air be thick with snow or thick with teddies?

The GEFS and EPS could not be more different for week Friday for NW Europe. One says deep trough, the other moderate ridge.

Of course hard frosts will certainly help lower ground temps as the high remains over or nearby... Low temperature warnings here in Ireland the last couple of nights.If you had no models and just looked out your window this Winter (autumn)is definitely unusual. Over 40 years of watching weather barring 2010 I don't recall such a frosty chilly November. I've a gut the models will dramatically pick up positive changes over the next 48 hrs. As GP eluded to earlier this mornings GFS may have been just a tad to quick... Enjoy folks.....2016/17 is gonna leave '10 in its shadow☺

It's not snow that's stressful. It's watching models. If we didn't have models we'd just go back the 'good old days' of "oh, hey, look, it's snowing".

Full support for GFS from control and ENS at 180....That with the GEM I say ECM is wrong - optimistic obviously great mean

Well today has been a classic on Netweather. The full house of good and bad runs, toys being lobbed left, right and centre and the GFS has once again been left with egg on its face! However, there are many reasons to be cheerful Today's bad runs would have been last years good runs Massive volatility which could result in a quick turnaround PV all over the show IT'S ONLY NOVEMBER 24TH FI on the the pub run is looking great!!!! Tomorrows runs maybe crap, but its only the weather. Watch the news for 10 minutes to get some perspective then come back onto Netweather and enjoy this rollercoaster ride.

I would say it is even earlier when you focus on the area of disagreement.

Stop spinning you should have been a politician! lol The UKMO is utter crxp, the GEM slightly less crxp, the GFS passable but still finds the shortwave from hell to spoil things. The only crumb of comfort is that NCEP aren't impressed with the outputs and theres a lot of uncertainty over in the USA. But we need the ECM to find a solution that at least has some positives, I don't care if it goes in a different direction as long as it has the prospect for something interesting!

almost trollesque.... "well dones" can be handed out after the event surely ? not based on one set of runs... this holds true whatever the outcome

It's a fence to protect neeps from being eaten by wild haggis.

Lets hope its not thick, in fact lets hope the thickness values are very low, between 500-1000mb!!! lets hope the 492 dam thickness puts in an appearance.

Today Very much a two way split between Scotland and the rest..The former will start with clear skies and quite a severe frost and the clarity will continue during the day with temps picking up but remaining on the cool side. Elsewhere the temps much higher, particularly in the south, but the price for this is remaining cloudy virtually everywhere. The significant factor here may well be the wind with a squeeze between the HP and LP. and the north easterlies will be quite strong down south and particularly in the channel. This morning's GFS Saturday sees energy tracking NE from the eastern seaboard and SE from N. Canada phasing to form a new low SE of the tip of Greenland that tracks NE pushing the HP east and forming a weak trough mid Atlantic. At 1200z Monday the high cell is over the UK Continued upstream forcing doesn't allow any meaningful development of the Atlantic trough but it does invigorate the energy running east from Greenland and another surge from the Azores HP which is quickly flattened by the former leading to a very tight thermal gradient and a strong jet running west to east over Scotland by 12z Wednesday. On the surface this translates to strong westerly winds, particularly over Scotland, which will also suffer some very wet weather From here the main trough to the NW drops SE and deconstructs leaving one arm running N/S to the west of the UK. An action that amplifies the Azores HP into Greenland with strong WAA between Greenland and Canada and CAA into the mid Atlantic. Best left here this is still wide open to various interpretations. So a quick summation of the weather in general. Remaining dry if rather cool until the beginning of next week when the situation becomes quickly unsettled with strong winds, very wet interludes and the UK and the eastern Atlantic under large, complex low pressure area. The temps during all of this very variable running from quite cool to just above average and then just below.

Hi, sorry to interrupt the thread but I’m not sure where to put this gift - Mods please move this post to a more appropriate place if you need to. I had saved many ensembles since Feb 2012 through to Jan 2016 plus a few others. There’s 32mb of info and just over a thousand images like this: If you want them please download them from my DropBox folder.. https://www.dropbox.com/sh/w8zj6ch1y96ytud/AAADvJcNQEkbLdKO3YX6Ife6a?dl=0 you'll have a week before I have to delete them. Hopefully some of you will find them interesting, maybe not? One week and they’ll be gone.. Pixel ps accept my apologies for mostly being interested (collecting data) in extreme weather - esp in the winter (-;