Model Output Discussion; into 2015

[Great Plum]

A typical day 10 ECM tease in FI or the start of the model 'picking up the signal?'

Scandi high - http://www.wetterzentrale.de/pics/Recm2401.gif

[weather_it_will]

A typical day 10 ECM tease in FI or the start of the model 'picking up the signal?'

Scandi high - http://www.wetterzentrale.de/pics/Recm2401.gif

Not much use though, when we have deep lows over Greenland and the Atlantic feeding in zonal westerly based winds.

[mountain shadow]

A typical day 10 ECM tease in FI or the start of the model 'picking up the signal?'

Scandi high - http://www.wetterzentrale.de/pics/Recm2401.gif

Looks more of a Russian high to me and to far away to stop the zonal train.

As mentioned yesterday, GFS caves in with any potential HLB.

[Great Plum]

Looks more of a Russian high to me and to far away to stop the zonal train.

As mentioned yesterday, GFS caves in with any potential HLB.

Well, a sort of Finnish/Russian high - it's pretty different to what the ECM had been advertising anyway...

GFS carves out a mid Atlantic high for a time in FI - maybe not nirvana, but still a signal for high pressure...

http://www.wetterzentrale.de/pics/Rtavn2881.gif

A definite sign on the 0z GFS ensembles that there is a change after 15 Jan - the sinuosity of the ensembles stops and the mean drops...

http://www.wetterzentrale.de/pics/MT8_London_ens.png

Edited January 6, 2015 by Great Plum

[karlos1983]

Not much use though, when we have deep lows over Greenland and the Atlantic feeding in zonal westerly based winds.

Seen many Scandi Highs survive Atlantic onsaught. I'd rather see that Pop up on the ECM than GFS. It's not an impossible outcome, more feasible than Grenland High.

[IDO]

Looks more of a Russian high to me and to far away to stop the zonal train.

As mentioned yesterday, GFS caves in with any potential HLB.

 

I am not sure anyone expected any blocking to sustain. The best we were going to get was a slowly toppling Atlantic ridge with maybe some snow and then 2-3 colder days. This Winter has shown no inclination for cold to the UK, its again US biased. 

 

No real change this morning as we look at deep FI. Heights somewhere in our sector having developed from around D12:

 

 No real signal as yet so anything from a toppler to MLB to a SW HP based flow.

 

That is the nature of most winters, looking for these brief potential cold interludes. Without an SSW we are going to be doing this for the next two months IMO. The signal from the MJO is COD before it gets intereting:

 

  MJVentrice

@MattHugo81 looks like another loop through the inner circle and back across the West Pacific http://t.co/2iXJkL6RFi

05/01/2015 21:01

 

CFS weeks 3-4 suggest a weakening of zonality during week 3 and back to square 1 in week 4 with heights to the east and the PV to the NW with the UK inbetween:

 

 

So its a case of waiting for the SSW, be it sooner or later.

[Captain Shortwave]

Well, a sort of Finnish/Russian high - it's pretty different to what the ECM had been advertising anyway...

GFS carves out a mid Atlantic high for a time in FI - maybe not nirvana, but still a signal for high pressure...

http://www.wetterzentrale.de/pics/Rtavn2881.gif

A definite sign on the 0z GFS ensembles that there is a change after 15 Jan - the sinuosity of the ensembles stops and the mean drops...

http://www.wetterzentrale.de/pics/MT8_London_ens.png

It was only yesterday that the GFS ens were going to around an 850s figure of -5C, today we are struggling to get to -4C as a mean for Aberdeen. The GEM and ECM by day 10 are not interesting in weakening the Atlantic jetstream compared to the GFS around that time. The ECM high later seems to be an over-expressed positively tilted Azores ridge so in the end that doesn't exactly help us either. 

Add to that there is usually scatter after 6 or 7 days anyway. To me it seems the GFS is losing the trend it had carried over previous days, though it's over the top MJO prediction looks to be one of the main drivers for that.

Edited January 6, 2015 by Captain shortwave

[Weather-history]

Seen many Scandi Highs survive Atlantic onsaught. I'd rather see that Pop up on the ECM than GFS. It's not an impossible outcome, more feasible than Grenland High.

The trouble is they may survive but often they deliver nothing, the UK is caught in no man's land. They are cold sucker charts, IMO. , you see the high pressure there, the Atlantic influence is still there. You tell yourself, that all is needed is for the Atlantic to run out of steam and you watch each run go by and before you know it, a week of winter has go and no sign of change, just look at last January.

[IDO]

A look at the jet shows that things are going to change a bit after D10:

 

 

 

From classic zonality to a messed up jet. That is no promise of cold but it will be better than the next 10 days.

 

Some off the chart gusts for NW/N/NE Scotland on Friday according to the GFS:

 

 

 

Snow chances for the W/NW and usual favoured spots from this Saturday for 5-7 days but way too early for specifics as they will change daily.

 

[BlueHedgehog074]

Looks like this bad boy (storm) out West on the GFS's Paralell run in FI doesn't wanna play nice...

Nice to see, though, some models like the non-Paralell GFS still play about with amplification to our West in FI (although the Northerly it does develop in conjunction with an Atlantic ridge eventually topples towards the end of the run. But not much support from other models, which is making me feel doubtful about GFS's Northerly idea. The 00Z GFS operational model is also a cold outlier in terms of the 850 hPa temperatures in FI. London ensemble graph used as an example:

It would suggest that the GFS could be over-doing the cold signal in 10 or so days time. But perhaps, however, should the Vortex become less intense to our North-West, then it could allow heights to build to our West or North-West. Although considering the models have shown possibilities like this in the past in FI that then get taken away as a more reliable time-frame approaches, then it could be just as easy for the same thing to happen again.

In the closer time-frame, and it looks to be mostly Atlantic dominated with Lows to our North and High Pressure to our South. An assortment of rain, showers (wintry at times, especially over Northern high-ground, and brighter, drier interludes with alternating milder and cooler periods. Apart from the cold front clearing South-Eastern areas today, most areas should see a brighter, drier day, though some wintry showers are possible towards the North-West. Quite cool, too, in the chilly Westerly flow.

As for this weekend, it does certainly hold some interest for those after something wintry. As an example, the GFS shows quite a chilly Polar Maritime North-Westerly flow taking over the whole of the British Isles.

Wintry showers possible for the North-West, though some of these possibly spreading further inland, as some others said, in that strong flow. Some of these also streaming through the Midlands from that Cheshire Gap. As well as the -5*C, or slightly colder, 850 hPa temperatures being supportive for showers to fall as sleet or snow to some reasonably low levels, the Dew-points look to be on the cold and snow fans' side as well.

Southern and South-Eastern areas do retain much milder Dew Points at first, otherwise most areas see Dew-points around freezing point or lower. This of which should be supportive for low-level sleet and snow.

With this possibility being a few days away, then further changes are possible (hopefully one of those cases where a Polar Maritime flow does not get 'watered down'). Still a nice feature for those after something wintry to look forward to.

[mulzy]

 

 

@MattHugo81 looks like another loop through the inner circle and back across the West Pacific http://t.co/2iXJkL6RFi
05/01/2015 21:01

 

Can someone explain that graphic to me?  I know it's MJO related...

[winterof79]

I suppose each of us interpret things differently.The GEFS as i see them are ok in continuation of MLB by mid month

http://www.meteociel.fr/cartes_obs/gens_panel.php?modele=0&mode=1&ech=300

Peturbations  1,2,3,8,10,11,13,14,16,19 and 20 all have a cold look to them with quite a few with low heights to our east and heights to our west.I would be happy for someone to look at them and tell me differently.I KNOW its 300z but the trend has been there for a mid month change for quite a while and the signs are there at 240z if you look also.

[carinthian]

Sad charts this morning for us cold lovers. The NWP models continue to show the predominantly Tm air mass flow into much of Europe until the weekend. Amazing temperature profile for the mountains in the Alps on Saturday, here in our part of Austria, 17C forecast at base station at just a little over 1000m asl and 9 C at 2000m. Not the best of expectations for the new Saturday arrivals to the slopes, but should turn colder later on Sunday. Winter moves on at a pace, lets hope to see that rock solid warm high relocate  fairly soon.

 C

[winterof79]

A look at the jet shows that things are going to change a bit after D10:

 

Meteociel_-_Panel_GEFS 15.png  Meteociel_-_Panel_GEFS 14.png

 

From classic zonality to a messed up jet. That is no promise of cold but it will be better than the next 10 days.

 

Some off the chart gusts for NW/N/NE Scotland on Friday according to the GFS:

 

75-289PUK.gif 90-289PUK.gif

 

Snow chances for the W/NW and usual favoured spots from this Saturday for 5-7 days but way too early for specifics as they will change daily.

 I have to say,IDO,those wind speed charts are a tad worrying for us Southern Penniners northward.We had gusts to 70mph last week and that buffeted the house.  There is the potential for blizzard like conditions also.

http://www.meteociel.fr/ukmo/runs/2015010600/UW120-7.GIF?06-06

http://www.meteociel.fr/modeles/ecmwf/runs/2015010600/ECU1-120.GIF?06-12

[Gibby]

HERE IS MY LATEST ANALYSIS FROM THE OUTPUTS OF THE WEATHER COMPUTER PREDICTION MODELS FOR TWO WEEKS FROM 8AM TODAY TUESDAY JANUARY 6TH 2015.

NEXT UPDATE WEDNESDAY JANUARY 7TH 2015 08:00

THE CURRENT GENERAL SITUATION A cold front clearing East today will be followed by a ridge of High pressure tonight and a warm front and strong SW flow tomorrow.

MODELS-2 WEEK HEADLINE Rather changeable and often very windy and sometimes mild with rain at times. Some drier interludes likely too with slight frosts at night.

THE JET STREAM ENSEMBLE FORECAST The Jet Stream Forecast shows a very strong Jet Stream being maintained across the UK or just to the North in the short to mid term before it quickly weakens later as the result of a weakening vortex to the North of the UK.

GFS OPERATIONAL The GFS operational continues to look very zonal, sometimes mild and wet, sometimes cooler and more showery but never particularly cold but nearly always very windy from a Westerly point. Later in the run though pressure rises sharply to the West and NW slipping East bringing a change to colder and drier weather with some wintry showers in the usual places before the High pressure collapses SE later taking its colder and frosty conditions with it and returning milder SW winds slowly back down from the NW by he end of the run.

THE GFS PARALLEL RUN The Parallel run is as yesterday more reluctant to show any meaningful rise of pressure from the West late in the run and while the run weakens the zonal Westerly weather conditions late in the run changeable weather under westerly winds remain the favourite weather type likely two weeks from now though probably less windy.

THE GFS CONTROL The GFS control run shows a very zonal period between now and the end of the run between High pressure to the South and Low to the North. Spells of rain and high winds are a threat for all areas at times in sometimes mild and sometimes cooler conditions with wintry showers at times over Northern Hills. Pressure does rise somewhat close to the South and SW for a time in week 2 but insufficient to break the pattern down before rejuvenation.

THE GFS CLUSTERS The GFS Clusters continue to show Westerly winds the more likely option to continue to be felt by all by Day 15 although the weakening vortex to the North will dumb down the Jet flow which does show a few options where High pressure becomes High close to , over or just to the SE of the UK although these do not hint of anything meaningful in the way of cold other than frosts.

UKMO UKMO shows a strong Westerly flow across the UK over the next 5 days with gales and heavy rain at times mixed with shorter and more showery interludes. It continues to show High pressure never being very far away from the South or SW though through the period continuing to dilute the very worst of the stormy conditions towards more Northern areas of the UK rather than all areas though all areas will have a stiff breeze as well as some heavy rain at times too in never overly cold conditions.

THE FAX CHARTS The Fax Charts shows a very volatile and active Atlantic flow as deep depressions cross quickly East between Scotland and Iceland with all areas seeing broad mild sectors with rain at times heaviest on Northern and Western hills  mixed with colder polar maritime Westerly winds, equally strong with showers, wintry on hills across the North.

GEM GEM today follows the very worn road of late with typical zonal January weather type with Low after Low moving East to the North of the UK with embedded fronts and strong winds delivering rain for all heavy at times especially across the North and West. pressure rises somewhat just to the South of the UK later steering the worst of the wind and rain towards more northern areas and away from the South where it could become largely dry and very mild later.

NAVGEM NAVGEM also shows a Westerly flow dominant across the UK over the next week or so. Some rain at times is likely for all but with some dry and bright spells at times too, none of which look like lasting very long. temperatures are shown to be on the mild side of average under the rainier periods and slightly on the cold side of average in the more showery interludes between the rain bands.

ECM ECM this morning shows little or no change in the mobile Westerly pattern of weather with spells of rain on fast moving fronts crossing East over the UK regularly, always more active towards the North and West especially later when Southern and Eastern areas are more likely to stay drier for longer then as High pressure lies close to the South or SE next week.

ECM 10 DAY MEAN The ECM 10 Day Mean Chart shows absolutely no change in the pattern this chart has been showing now for nearly two weeks with Low pressure likely to be lying to the North of the UK and High to the South and SW with a broad zone of Westerly winds over the UK delivering a continuing mix og generally mild and changeable weather with rain at times and slightly colder weather in the brief showery interludes between the rainbands.

NOTABLE TREND CHANGES FROM PREVIOUS RUNS The trend this morning remains largely usettled and windy with spells of rain at times and short colder spells with showers. Yesterday's hints of more High pressure likely to be in the mix during Week 2 have been diluted in extent this morning..

MY THOUGHTS In a Winter that is becoming increasingly difficult to say anything that's different than what has already been said that very story continues again today. The models can no longer be said to be stuck in a rut as they are best desribed as stuck in a trench with little or no give in the current pattern whatsoever in the next few weeks at least. Some commentators suggest that this Winter is at least better than last Winter in regard to cold due to the fact that we have had some frost and a brief snowfall (for some only) well that to me doesn't constitute a Winter as it's something you will get in any Winter though I concede last Winter was an exception to that rule. Over and above that the synoptics have been nothing but dire for the UK in the likelihood of impending cold since way back in November with all the talk and excitement of SSW's changing the course of the weather in the UK proving a red herring to say the least with the models quite rightly not being drawn into the propagation of that down through the atmosphere in a way to affect this part of the hemisphere. In my opinion the models have generally read the script very well this year and the Met office's mild call is well accredited so far so all I can say is why has it been so benign and boring for cold lovers.  The two factors that 90% of the time affects the weather over the UK is the Jet stream and the position thereof and the Azores High. Forget Scandi High's and Greenland ones's  because if both of those two factors I mention are strong as they have been all Winter so far then they will always overpower the strength of anything else. If one of those powerhouses is weak then the door opens for something more akin to what folks want to see can emerge from a displaced jet or a removed azores High and to have both displaced or removed can lead to the holy grail for coldies but is as rare as hens teeth in Winter. So how does this fit in to the next two weeks output issued today. Well firstly the Azores high is going nowhere with it's positioning shuffling about and if anything favouring even milder and less wet weather at times to Southern Britain later in this morning's output. The unusually strong Jet flow at present remains that way for some time to come but does show signs of weakening later which could at least slow the pace of the changes in weather variability and does lead to options of stronger ridges to give longer drier interludes with some frosts returning by night but that is the best that can be offered in what I see in the models this morning. As I have said before those looking for cold want to look Southwest for cold and not just Northwest, North and East because as long as there is a large, strong  warm High pressure down there with an overriding Jet over the Atlantic any needed requirements elsewhere synoptically will have a mountain to climb as it's odds on that any cold will be muted, shortlived or non-existent and for these reasons this has been proven so far this Winter.

[knocker]

The extended ECM EPS mean anomaly at T336 is not dissimilar to the T360 from yesterday that can seen here. So no real indications still of any major pattern change.

History doesn't repeat but sometimes it rhymes...January evolution similar to December evolution? pic.twitter.com/JMO5GhNXNX

[mushymanrob]

not sure what there is to discuss this morning... just detail on the overall pattern which screams 'average'.

[JOPRO]

Could this be the classic situation where the GFS picks up the trend in FI drops it for a few runs only for it to return with a vengeance in later runs? I am sure I have seen this on numerous occations over the last 5 years of lurking/watching models on here. Wasn't that what happened with the famous Ian Brown WTF moment a couple of years back?

[knocker]

All the eggs in this basket? I wouldn't put money on it.

 

[Jason M]

not sure what there is to discuss this morning... just detail on the overall pattern which screams 'average'.

I'd agree with this. Maybe the one plus point being that entropy is trending higher after 10 days, so whereas last week it was safe to guess that there would be no notable cold spell within say 20 days, that maybe drops to 10 - 12 days now.

Picking up on the GEFS, there are still some decent runs in amongst them but the position of the PV looks to remain centred around Greenland and as such any attempt at HLB will just sink. Yesterday it looked like the PV might move away from its current locale. Will be interesting today to see whether the negative trend is a blip or whether it continues.

Based on the snippets from Fergie the METO are not seeing anything out of the ordinary at present either.

[mushymanrob]

Could this be the classic situation where the GFS picks up the trend in FI drops it for a few runs only for it to return with a vengeance in later runs? I am sure I have seen this on numerous occations over the last 5 years of lurking/watching models on here. Wasn't that what happened with the famous Ian Brown WTF moment a couple of years back?

 

good point sir! a valied one too.... however theres no real sign in the anomaly charts of major ridging being a player near the uk in the next 2 weeks. currently.

[IDO]

Another possible nasty storm D8:

 

 

Comes when the uppers are cold but at that depth would probably bring a warm sector. However again possible snow/blizzards on the back edge?

 

The GFS 06z P also similar and it drags in behind a cold upper flow with snow potential: 

 

One to watch...

[IDO]

The GFS op after D8 is relatively flat and it's not till D16 that it offers anything interesting:  

 

The heights now around D10 are still there but a short wave flattens the ridge on this installment: 

[MR EXTREMES]

A very good post by gibby and he's bang on with his strong uk direct jet and heights to our South that is and has been the curse of winter 14/15 so far.

Although in fi I still see the heights building ne of the states but this could retrograde towards Greenland all be it possibly to far west.

Also could be that the vortex moves more East of the Greenland area perhaps encouraging more in the way of nw flow polar air,

But only if the Azores or heights to our South decline even without the heights to our South things would be much better.

Be nice to just see this feature move away to allow the jet further south.

Some might disagree but this feature of Northern jet and Azores heights has been a totally thorn in our sides and I can't wait for another solar minimum when the jet seems to like holidays down into Africa but the next solar cycle is in 2020 so suspect that things will decline in the next few years thus the return of the eye candy of the great winters.

This said there are still some hints and background drivers to play for and all is not lost just yet.

This is looking likely to be the longest zonal pattern set this winter so far so if I were to be realistic then I don't see a change or a marked change with in the next fifteen days from zonal every model is certain of this but it's still early January so still time.

[Nick F]

Oh dear, 06z GFS operational continues to dash hopes, as 00/06z GFS P, for even a transient mid-lat high

 

Though wouldn't give up hope quite yet on the idea of a mid-latitude high or even a block after mid-month, but high latitude blocking is looking unlikely, perhaps for the rest of Jan given the persistence of the strong trop PV to the north .

 

Hints from GEFS and EPS of a pattern change upstream over N America from mid-month, as west coast ridge slides east to the east coast by Jan 19th (from -EPO to neutral/+ EPO). Not sure how this movement will affect downstream, as we are still stuck with a strongly +AO/NAO pattern with PV stuck to our north, it may entice a MLB, but perhaps not favourably for cold.

 

 

06z GFS op looks quite cold next week though, with the jet further south than 00z op, but that means any deep lows that develop over the Atlantic could cross over the UK rather than to the north, as the 06z alarmingly demonstrates.

Edited January 6, 2015 by Nick F