[Model Output Discussion 19th January 2014-18z onwards.]

   

didnt they have cold in december ? it may be that feb sees the trough back west again. that could tie in with a generally retrogressive hemispheric movement ...............

Danger of drifting off topic here, but yes ba they had a very different Dec to us, in fact Dec 13 was the coldest month of the year in Fairbanks.

 

Even towards months end it remains very mild, with the -5c line having extended NW into Siberia, but certainly some signs by then of a change in the overall hemispheric pattern upstream...what that will mean for our little island come early Feb though remains very much open to question tho imo.

 

[Model Output Discussion 19th January 2014-18z onwards.]

Meanwhile, purely out of interest at least we are not the only part of the N Hemisphere experiencing a mild Winter.  850 temp 12-14c in parts of W Canada, with not one part of Alaska north of -5c line and only 30% north of the 0c line...that must be a first for late Jan.

 

[Model Output Discussion 19th January 2014-18z onwards.]

Some pretty good agreement between the big two at T+240hrs, particularly in view of the range involved.  Bottom line is block gone, Atlantic in charge. Whether this actually transpires of course remains to be seen, but in the absence of anything else to suggest it won't I think we have to consider it to be more likely than not at this stage.

 

GFS

 

 

ECM

[Model Output Discussion 19th January 2014-18z onwards.]

Well he's been right so far unfortunately but I think there are changes afoot. I think the jet will be displaced further south as time goes on due to the intensifying cold block to the north east, it's only a matter of time now before wintry weather gains the upper hand for the first time since last april.

Probably true from Germany NE'wards Frosty, but still no concrete evidence that is going to happen for the UK as a whole imo, at least not across the remainder of Jan... Quite the opposite in fact IF the 06 is to be believed

[Model Output Discussion 19th January 2014-18z onwards.]

06 GFS fails to move the LP southeastwards quickly enough before the next system moves in off of the Atlantic so no NE'erly, then to compound the problem the block looks set to be in retreat, with heights falling from west to east across Scandi by this time mext week.

 

[Model Output Discussion 19th January 2014-18z onwards.]

Frosty I agree entirely , I think we're a lot closer now than the previous 6 wks , the models look full of interest , really puzzled by the downbeat nature this morning . Trough disruption with northern blocking on the 2 big 2 , yes the ECM is not too good but 2 out of 3 isn't bad. Snow for quite a few Sunday night and Monday , a taste of reall cold zonality for a change , followed by a very very cold block moving west. That to me screams potential , yes people get fed up of this word and it's understandable given the winter so far but things really are changing aloft and the vortex is prone to distortion and splits from now on given the change to the weakening westerly waves due to seasonal progression .But even if we don't see any snow this year which is highly unlikely it's not the end of the world and we all know how fast time goes by , another 9 months and it all starts again , but having past the solar maximum and in an -QBO faze next winter is already better than this one !!

Can I ask where are you seeing the 'very, very cold block moving west' after Monday SSIB?

[Model Output Discussion 19th January 2014-18z onwards.]

Perhaps the best thing to do is not to take the models at face value and not think to deeply about immediate snow and just wait and see what evolves  

Very clever aj...

 

Whilst those are wise words, the main problem is we've been doing precisely that since mid November. Unfortunately Winter does have a life span and as such the wait cannot go on indefinately.  Clearly with 6 weeks still to go we remain 'in with a chance', but it won't be too long before we reach a point of no return as far as proper winter cold is concerned.

 

Wouldn't mind a quid for every time the 'P' word has been used in here since November, but the fact remains absolutely none of it has yet been realised...note YET....

[Model Output Discussion 19th January 2014-18z onwards.]

Another set of overnight runs resembling a dogs breakfast, with more questions posed than answers provided.  UKMO on the face of it looks good, but we have seen plenty of other decent charts from it in the 120-144hr range that have failed to deliver, so probably wise not to assume it will be right this time.  Despite more variations on a theme, the overall problem of getting the LP's (hate the term energy!) southeast of us before the next ones develop and move into mid Atlantic to cut off the potentially cold NE flow still exists. 

 

As I said yesterday the cold air hoofing off of NE Canada again looks set to provide near perfect conditions for LP development, as it as done for much of extended Autumn, so regretably I'm still seeing nothing to suggest that the block will win out. I still looks to me as if the best we can hope for overall is enough westward correction to stall the fronts across us, but even that looks a bit of a stretch at the moment, with a continuation of a broadly similar pattern to now probably being fave to close out Jan imo.

[Model Output Discussion 19th January 2014-18z onwards.]

In general terms there has been very little change to the met office outlook apart from a weak signal for high pressure to eventually build across the south so where does that leave us with a pattern change? I think the models so far today are showing more wintry potential than yesterday, especially the 12z output last night which pushed the cold further east but once again there has hardly been any movement from the mo with the type of disturbed pattern we had through dec and early this month being the form horse, so i'm assuming that mogreps is not showing anything significant in terms of snow & ice for the next 2-4 weeks.

I thing it's very unlikely that the block will get completly blown away Frosty, so the chance of a return to Decembers set up whereby system after system blasted across us, N Europe and even deep into W Russia looks low. However, I don't currently believe the block will extend sufficiently westward to put us into the freezer either, so the best we can probably hope for is enough westward correction to make us rather than the North Sea the frontal graveyard, that way ensuring that some areas, particularly across the east see at least some snow at times.  Up until very recently I was fully expecting a very wintry Feb and to be fair those on a N Sea oil platform might still get one, but now I'm leaning ever more towards normal to rather cold in the east and normal to rather mild in the west. 

 

Edit-: Hadn't seen yer post gtltw, but hopefully the above fits the bill...

[Model Output Discussion 19th January 2014-18z onwards.]

I couldn't agree more! In 2012, late October of early November I think, a front moved across the South of England and with evaporative cooling and cold northerly surface flow caused very heavy snow over parts of Somerset and Dorset! If that can happen in Autumn, when conditions are not normally favourable for wintry weather, then the persistent tendency for the models to show cold north-westerlies appearing in the next week or so is even more promising! Sometimes the best winters are about the surprises!

Fair point Joe, anything is better than nothing, but after more than half of a so called Winter that's been mild and soggy I think most in here crave more than a very localised, transient wet snow event.

[Model Output Discussion 19th January 2014-18z onwards.]

That part of the winter was predicted as a write off very apparent reasons. A very powerful vortex building under a strongly ramping up polar westerly background pattern which relocated the vortex to Canada and Greenland after some temporary attempted amplification of the atlantic pattern (largely failing) while the vortex resided towards Siberia in late November and as a poleward -EPO ridge in evidence at the time broke down.

 

The situation now is in reverse with the dissembling of the vortex in sequence, plus all the other factors in play which I listed in my most recent post. On that basis, for the reasons I gave in that post, we need to be very careful how we interpret current ensemble means. These are, and will continue to prove, fickle and volatile.

 

The dominant signal apparent from those ensemble means, and including the 32 dayer, is very skewed atm by the large quantity of players in evidence, as mcweather appropriately describes them, and as I listed in my earlier post. The atlantic signal is very uncertain in terms of amplification in the days ahead, and in tandem with pressure rising over the pole and further attempted vortex attacks in the pipeline  - then taking ensemble means at face value is playing with fire even more than it usually is. Especially as these are swinging one way to the other, from one suite to the next suite.

 

Its a pattern knife edge and all bets are off at this time

Not suggesting it wasn't Tamara, some of us could see that quite clearly, but that didn't stop the constant howls of derision towards anyone who suggested as much at the time. As you, I and many others have said we are very much on a knife edge now, with precious little required to tip the balance significantly in a number of directions, but for now everything that I can see favours W'erly rather than E'erly domination...that of course can and may change very quickly however.

[Model Output Discussion 19th January 2014-18z onwards.]

Agree wholeheartedly with the above Tamara.

 

Those writing off the rest of winter simply by looking at the current modelling could well end up with egg on their faces come early to mid feb.

There seems to be a touching faith in the the ECM 32 dayer etc. The meto long term updates etc. Over the years I have found that if there is no overiding signal for cold ( ie late Nov Dec 2010) then both of these will trump for average winter conditions ie some kind of west based flow.

Models perform best when there are overriding signals, when there is great uncertainty like there is now with ( as you pointed out ) numerous players at the table. They are far less reliable at picking the eventual outcome. Hence the see sawing especially in our corner of the world. One only has to look at how the models uhmed and ahhed in advance of last Jans cold/snowy spell to see this in action

 

In our geographical position the test of any model is how accurate will it be when things aren't flying in off the Atlantic at high speed.

Then again they could be absolutely right, as were those who wrote off Dec in late Nov and those who wrote off the first half of Jan in mid Dec....not that anyone has seriously written off Winter at this stage of course. Completely concur with your final sentance though, that process has been arrested for now and already it's very clear the models are struggling post T+120hrs in particular - the question is will that continue or will the Atlantic start to smash though once again?  Answers not to far away now imho.

[Model Output Discussion 19th January 2014-18z onwards.]

As far as I'm aware there's no archive for the Ensemble means though, so I couldn't show that. It's more about the folly of calling anything 240-400 hours away "odds on", especially with the background signals showing in the Strat forecasts.

I think when considering this we have to look at the difference between a person calling this and the models calling it. 

 

Had someone come on here and declared 'I don't bother looking at the models, but a return to zonal is odds-on in 10 days time' I think your point would be far more valid. However all Draztik has done is posted an ECM 10-15 day chart that show a return to zonal and from that (along with other data sources) has declared it's return odd-on.  Also worth considering what odds-on means too. All it says is it's the most likely outcome, it does not preclude all or any other options, which as we know remain firmly on the table at this point in time.

 

If every odds-on shot won, I'd be a millionaire...

[Model Output Discussion 19th January 2014-18z onwards.]

Excellent posts above from Draztik (again) and also Bobby, perhaps rather to full of unpleasant truths for most of us, but that's just the way it is for now.

 

Up until T+144hrs things now look pretty much sorted in general (though of course the finer day to day detail will continue to change), but it's at this point that we have a shot at initialising a major change for us, IF we can force a much stronger, more robust ridge from the Azores to Greenland.

 

 

If that fails to materialise as the majority of the current modelling (and the MO outlook) suggests, we may then really be struggling to set up anything in the way of proper cold this side of mid Feb. So plenty on the line in the not to distant future now, perhaps not quite **** or bust yet, but heading inexorably towards it imo. 

[Model Output Discussion 19th January 2014-18z onwards.]

Incidentally, CFSv2 has been rather consistent with its advertising of colder solutions through mid-February and extending into March.  This pseudo trend isn't too dissimilar to how it equally advertised colder synoptics in February 2013, albeit a fair bit more moderate.  The broad synoptical picture is an omnipresent high pressure cell centred over Scandinavia; consistent in synoptical flavour with stratospheric downwelling propagating through to the troposphere.

 

Whilst GS5 isn't wholly reflective of that which CFSv2 proposes, that isn't to say that its broad synoptical proposal should be dismissed out-of-hand.  Variance is high and that isn't unexpected; at mid-range it's not so much about detail as such, but more broader patterning.  If consistency can be identified in that context, then confidence can be raised, and detail ascribed once within range of more conventional NWP modelling suites.

 

Boom Boom Boom, let me hear you say way-oh, way-ooh! 

 

It does appear that the MO are for now at least focussing on an unsettled theme, with the big Sunday/Monday LP already in their thoughts...and probably plans. No indication that any undercutting of the block is currently expected, but I suppose given the complexities of the pattern going forward a short term seachange of emphasis is not wholly out of the question.

 

UK Outlook for Sunday 26 Jan 2014 to Tuesday 4 Feb 2014:

Turning very wet and windy on Sunday, with the heaviest rain and gales, locally severe, in the northwest. Rain should clear to sunshine and squally showers on Monday, with the best of the brightness in southeastern Britain. Mild at first in the south but turning colder. Thereafter the unsettled theme is likely to continue, especially in the north and west of the UK. Bands of rain are likely, with hill snow at times, interspersed with clearer, colder, more showery conditions, and brisk winds.

[Model Output Discussion 19th January 2014-18z onwards.]

Whilst most eyes understandably remain focused on 'wintry potential' there's no escaping the fact GFS is wanting another significant storm later in the weekend. Showing up on the 06 as sub 945mb, which is probably a bit to low given the GFS's perpensity to over deepen things, but I suspect the MO's attention will be rather more drawn towards this over up coming runs rather than snow and ice.

 

[Model Output Discussion 19th January 2014-18z onwards.]

Just looking across the other side of the pond for a moment any pattern change looks very unlikely there right through until the end of the run.  Having already had several 3-4 day bitterly cold spells across the northeast they are now about to be plunged into a 7-10 day period of severe cold weather, which even at 240hrs looks absolutely locked in, with the next plunge already showing it's hand across NW Canada. Whilst I realise it's not impossible to get cold here when the Eastern US is in the freezer it does make things a lot more difficult, especially in light of the fact shedloads of cold fuel will continue to pour into the NE Atlantic, much as we have seen all extended Autumn so far.

 

[Model Output Discussion 19th January 2014-18z onwards.]

Just as it was unwise yesterday to scream Winters over on the back of one run, it's equally unwise this morning to assume Snowmamadden is imminent, both are off the mark. What we have witnessed across the last 24hrs is typical winter model variation in the T+120hr range and as the coming few days unfold I think we can expect a lot more of the same, but on balance it does look as though some sort of 'colder' spell is more likely than not by this time next week. Exactly how it manifests itself, how deep it is and what longevity it manages to achieve remains very much open to question however, but as ba said the overnight ECM profile is not good for sustained cold. 

[Model Output Discussion 19th January 2014-18z onwards.]

The latest GFS and UKMO T+144hr charts both have the Atlantic bowling on through with what appears to be little resistance by this time.... lets see what ECM goes for, but I think we are rapidly closing in on a point where it may become very difficult to salvage much from this hiterto dire extended Autumn.

 

GFS

 

 

UKMO

[Model Output Discussion 19th January 2014-18z onwards.]

Yes as i posted above they are a bit chocolate teapot ish.

 

Unlike this fax chart which has some 528 Dam in the mix

http://www.weathercharts.net/noaa_ukmo_prognosis/PPVL89.gif?31415

You really want to see sub 522 tho, that fax chart IF it were to verify would be unlikely to produce lowland snow in all but the heaviest bursts of ppt imo.

[Model Output Discussion 19th January 2014-18z onwards.]

I must take you up on your point.

I was showing what the suggested output was according to the 06z GFS not me, people on here can make there own mind up.

Equally one could say that your prediction above is misleading as the GFS output would bring snow to lower levels up here.As "Im Dreaming" responded,looking more favourable for the North/North East.

I was referring to this, not the charts you posted.

 

 

 

Also said the same in an earlier post.....

 

Shedhead

Indeed...the 06 ENS have the Op rather more in the middle of the solutions, rather than one of the coldest as it was on the 00. Still think we are a long way from seeing the post T+120hr evolution decided, but for now I think the milder Atlantic option is probably slight favourite to win out overall. However the farther northeast you are, the better your chances of seeing some of the white stuff, especially on high ground. 

[Model Output Discussion 19th January 2014-18z onwards.]

Hi

 

No probs.

 

The GEFS mean.

 

T180: gens-21-1-180 (2).png  T240: gens-21-1-240 (4).png T300: gens-21-1-300 (1).png

 

The way I read those mean charts are that they are showing a cool zonality. There is no mean Scandi high; an euro/Russian one maybe.

 

With regard to transient snow, the GFS charts suggest maybe 2-3 short spells of snow for certain areas; too early to be conclusive as small changes can make a big difference but I don't see large scale snow downfalls though where you are, up north with height you will be in the luckier category, but us southerners, not so.

Yes, the kind of charts posted to suggest widespread snow on Saturday can be notoriously inaccurate/misleading at T+48hrs, let alone T+132hrs. As you suggest transient, localised falls currently look about the best on offer based on those charts, with ground above about 200-300m standing the best chance of picking up a temporary covering.  Considering the complexities of the overall pattern however, I'd be extremely surprised to see what is being progged post T+72hrs getting delivered, plenty more chopping and changing to come even in the relatively short term imo. 

[Model Output Discussion 19th January 2014-18z onwards.]

Still very uncertain how things will develop from now onwards with no clear signal.

Seems to look coldish for a while then a  lot of scatter again in FI land

 

 

With no sign of any SSW soon it looks like average conditions with colder shots possible mostly for northern areas I guess.

Indeed...the 06 ENS have the Op rather more in the middle of the solutions, rather than one of the coldest as it was on the 00. Still think we are a long way from seeing the post T+120hr evolution decided, but for now I think the milder Atlantic option is probably slight favourite to win out overall. However the farther northeast you are, the better your chances of seeing some of the white stuff, especially on high ground. 

 

EDIT: Pretty much in line with the MO's latest thoughts according to Frostys latest post....

 

Frosty

Posted 21 minutes ago

Met office update indicates average weather unfortunately with a mix of mild and colder days, more gales and rain, snow on northern hills at times and frost / fog in the quieter interludes which is what we have now. Tonight looks very foggy in places so watch out for that..no pattern change on the way according to the experts but not constant mild mush either. There will be some wintry weather at times, just nothing sustained.

[Model Output Discussion 19th January 2014-18z onwards.]

 Not necessarily a mild Atlantic for long if the 06z were to come off post t+228.

I said 'milder' Nick not mild, which when compared with what could still potentially move in from the east was the correct word to use. Re post T+228hrs who knows? Ever T+120hrs is very much up in the air.

 

Looking at the 00z London ENS it was clear the Op was very much on the colder side post T+120hrs...all the 06 appears to have done is corrected somewhat closer to the mean, which is where i think it will sit when it's ENS become available.

 

[Model Output Discussion 19th January 2014-18z onwards.]

06 GFS fails to bring the Iceland/Faroes LP southeastward in the same way the 00 run did, meaning an end result closer to what ECM was going for at T+192hrs and

eventually leading to a return of the milder Atlantic.

 

Still plenty more chopping and changing of evolution expected post T+120hrs, but overall this remains very finely balanced indeed, with cold no more likely to win out than mild...and visa versa.

 

If ever there were a case of the all to frequently used term 'more runs needed' then then this is it....so, more runs needed.

 

06 GFS

 

 

 

 

00 ECM