Model Output Discussion 1st January 2014-06z onwards.

[Downpour]

ECM delivers the goods at T190hrs. GFS starts the day with wrist-slitting fodder before backtracking then finishing up with a near hurricane that would plunge most of the UK into a Waterworld-style scenario with only Kevin Costner and a few oddly dressed extras for company.

I think it's fair to say the models are struggling.

[itsnowjoke]

Just heard on channel 4 weather its that cold In part of America if you spend more than five mins outside it will freeze ya eyeballs now thats what i call a Winter.

[nick sussex]

Indeed Nick, far too much variance at this moment in time so I'll keep my feet firmly planted on terra firma until the upstream pattern is resolved.

Yes I'm afraid I won't be rushing out to buy a sledge going on tonights ECM output, it looks great two possible snow events depending on trough disruption but the upstream differences from a very early stage leave me rather nervous in terms of accepting any of tonights outputs.

 

The ECM for me doesn't have enough sharpness to its troughing and the upstream pattern needs to be more amplified, its move from 168hrs to 192hrs also rings alarm bells.

 

Everyone knows I'm firmly in the coldie camp but the ECM simply does not fill me with confidence because its an accident waiting to happen, not saying its overall evolution won't verify but I need to see a lot more margin for error.

 

You'd need a lot more energy going se at T144hrs and then the phasing of upstream energy with the low to the west will pull low heights into the high to the ne at T168hrs this is another concern.

 

Its an interesting output and if people want to see some snow then this type of set up with trough disruption near the UK can provide that but its really how far east/west the pattern will be that's a big issue here.

 

I hope people don't think I've swallowed a misery pill or trying to put a downer on some excitement in here, I just have to be totally objective here, I certainly will ramp things up if I think it passes the muster in terms of a solid less stressful  evolution!

Edited January 6, 2014 by nick sussex

[weather eater]

We still can’t quite shake the theme can we, at least not yet, zonal, some sort of HLB/MLB and back to zonal, at least we can get past the GFS playing catch up to the ECM argument because the ECM has thrown a tangent, in reality it’s the usual story past 144hrs all the models are playing catch up.

 

What I would say is that tonight output has put some flesh on IFs post earlier.

 

 

“Any meaningful public communication of key expected weather type is almost currently impossible beyond mid-Jan and it's highly unlikely we will be any closer to the likely outcome anytime soon. â€œ

[Stuie]

Finally can yank out the BBQ again, shorts on, lotion...

 

Many mentioned including myself (for what it`s worth) a change around the 13th. Could it? At least there is something decent to look at.

[chris55]

Nowt going over the top on the ECM!! Very good run IMO. Low pressure into Europe is much more preferable than a toppler.

 

 

No fireworks on this run, but overall a nice trend from ECM.

[lassie23]

The Korean long range model which was showing an easterly freeze for February, could be right after all. The models are moving in the right direction, but it remains only a hint that winter proper will arrive soon.   Enjoy the weather whilst you can mildies.

[Jason M]

Yes I'm afraid I won't be rushing out to buy a sledge going on tonights ECM output, it looks great two possible snow events depending on trough disruption but the upstream differences from a very early stage leave me rather nervous in terms of accepting any of tonights outputs.

 

The ECM for me doesn't have enough sharpness to its troughing and the upstream pattern needs to be more amplified, its move from 168hrs to 192hrs also rings alarm bells.

 

Everyone knows I'm firmly in the coldie camp but the ECM simply does not fill me with confidence because its an accident waiting to happen, not saying its overall evolution won't verify but I need to see a lot more margin for error.

 

You'd need a lot more energy going se at T144hrs and then the phasing of upstream energy with the low to the west will pull low heights into the high to the ne at T168hrs this is another concern.

 

Its an interesting output and if people want to see some snow then this type of set up with trough disruption near the UK can provide that but its really how far east/west the pattern will be that's a big issue here.

 

I hope people don't think I've swallowed a misery pill or trying to put a downer on some excitement in here, I just have to be totally objective here, I certainly will ramp things up if I think it passes the muster in terms of a solid less stressful  evolution!

 

Completely agree with this. The evolution between 168 and 192 looks bizarre to me. Its almost as if the two charts are from different runs they are so different.

 

The 192 850 chart made me laugh. Seeing the -6 line sitting 10 miles of the east before it retreats eastwards would surely sum this winter up!

 

240 would be a nightmare as presumably that would be a game over chart. Of course its nonsense at that range and won't verify.

[legritter]

ECM delivers the goods at T190hrs. GFS starts the day with wrist-slitting fodder before backtracking then finishing up with a near hurricane that would plunge most of the UK into a Waterworld-style scenario with only Kevin Costner and a few oddly dressed extras for company.

I think it's fair to say the models are struggling.

Ithink if we look across all models plus the long range met office update the future is very interesting with possibly newsworthy weather to take us to the end of January .Colder air to our possibly east or n /east and an atlantic still breathing .but the end of this Month is 3 weeks away so no model as far as i know would have a clue , of  course met office are touting a possible cold spell at the end of this month probably going by their research involving upper atmosphere with new computer etc .So we need some good upgrades over coming days to go with tonights better charts .

[ANYWEATHER]

Tbh, my main concern from both models, is  that we see some sort of blocking to our East or NorthEast byT+192. The Ecm more so than the Gfs...Given this scenario it would seem likely that fronts would slow down considerably from the Atlantic and my thoughts are nothing to do with how cold it might get but some more flooding problems due to the fact we may get stalled fronts or even slow moving fronts over the nation.given loads of cold rain, and to add to that the over saturated ground..... difficult one to call but could well be an issue in the days ahead,,,,  

Edited January 6, 2014 by ANYWEATHER

[nick sussex]

Let me explain why I'm a  bit nervous of the ECM output, for those who like maths or into angles! we simply don't have enough angle between the low to the west of the UK and the next one over Newfoundland.

 

This is important because this is a factor in directing where the energy will go from the low to the west, the high to the ne is doing its best to force the low to disrupt some energy but needs a little more help.

 

The first is the angle on the ECM operational run at T144hrs:

 

 

Second the angle we'd like to see:

 

 

Third my higher margin for error set up:

 

 

You can see there we'd like more energy heading se towards Iberia.

 

Just roughly perhaps the troughing further west than I've shown there, now part of the reason for this starts off because of differences upstream regarding Pacific energy flowing into the nw USA, the models handle this differently, there is uncertainty over that region as to the amplitude of the flow, phasing issues aswell as timing are downstream causing these globally small but important issues re the building blocks towards a colder outcome and perhaps snowier one for the UK.

 

To be honest you could write a book on tonights outputs because there are so many smallish things that appear at one point or the other that impact things.

 

Overall the output is interesting but very fluid and so its hard to say exactly where this all ends up, much depends on whether we keep the positive anomaly to the ne, its complex and for that reason we're just going to have to see how things develop.

Edited January 6, 2014 by nick sussex

[R.P. McMurphy]

 

back to the models...

 

 

As above.. Some places might see some snow from this chart, but height will help greatly. It's a long way off, but most of the models appear to be latching onto something colder during the second half of January. The only problem is, it's not too long before the Atlantic starts to fire up again.

 

We really need the cold to dig in to our East and push, push, push, or I fear it's going to be over rather quickly.

 

Time will tell, but very interesting developments, and finally a good time to be looking at the models !

Edited January 6, 2014 by phil nw.
As requested by op

[SMU]

Surprised by some of the posts this morning. Still, we lack consistency across the models, with the GEM gravitating towards GFS in its evolution. The ECM still going with heights to our NE, but its 10-15 ensembles are starting to drift towards a more zonal outlook. With gefs by Jan 20th, keeping the mean trough to our NW.

Day 10-15 heights ecm, gefs 6z mean t336

 

 

Evening All

 

Sorry to be a pedant on your posts Draztik - your analysis of the 00z Ensemble mean - returning to zonal seems quite suspect as you *may* be interpreting the GPDM intervals as the prevailing wind direction, when actually there not.

The lines are showing you the depth of height anomaly -  whilst you could intimate that westerly conditions maybe pushing through, you could also say that the UK could be under a battle ground scenario with the polar front straddling the UK, or even that the high pressure in the atlantic was ridging NE to reinforce the cold anomaly over us & Europe- its not always right to put the first assumption in as your punt as to whats happening.

 

 

Onto tonights models-A few subtle changes from this mornings update-

http://forum.netweather.tv/topic/78936-model-output-discussion-1st-january-2014-06z-onwards/page-65 post #1285

 

So

ECMWF Confidence in Long wave pattern at day 6-8  Down from 60% from 65%

 

I think maybe tonight whilst the ECM looks different at 192/216/240 the core longwave pattern is quite the same just at slightly different locations - the key being the ridging at T144.

ECM has been uber consistent with this amplification.- suprisingly out further than we give it credit for:

 

4th 00z 192

http://www.meteociel.fr/modeles/ecmwf/archives/2014010400/ECH1-192.GIF?00  note the low is amplified but positively tilted

4th 12z 192

http://www.meteociel.fr/modeles/ecmwf/archives/2014010412/ECH1-192.GIF?12 amplified but still a bit flat

5th 00z 168

http://www.meteociel.fr/modeles/ecmwf/archives/2014010500/ECH1-168.GIF?00 more amplified ( note the more vertical component in the flow)

5th 12z 168

http://www.meteociel.fr/modeles/ecmwf/archives/2014010512/ECH1-168.GIF?12 more amplified carrying a wedge of heights towards Svalbard with undercutting

6th 00z 144

http://www.meteociel.fr/modeles/ecmwf/archives/2014010600/ECH1-144.GIF?00 same as yesterday- a wedge of heights towards Svalbard with undercutting again

6th 12z 144 & 168 current

http://www.meteociel.fr/modeles/ecmwf/archives/2014010612/ECH1-144.GIF?12

http://www.meteociel.fr/modeles/ecmwf/archives/2014010612/ECH1-168.GIF?12

 

 

With the ECM tonight I think we are doing the model some injustice where its been bang on the money @ 120 / 144 & very very good at 168 with pattern hints @ 192.

 

I would disagree with the assessment that the ECM has really changing a great deal from the 00z solution, it looks different but that's from the delicate balance between the energy flowing between a split flow, in terms the highlighted bit above the ECM over the last 3 runs has seen 'more' energy into the southern arm of the split jet as opposed the northern side, as a result undercutting is increased & the height at which the scandi high develops becomes increasingly higher- close to Svalbard.

When that low ridges North at 120/144 so it sends a wedge of high pressure North with it hence then the split flow-  it then gets sheared apart & get sucked into the new low forming off the states @ 192.

 

The 216 charts are excellent, however a 'smidge' to far east, but again at this timespan easy to rectify.  In terms of possibilities the 00z seems the lowest amount of undercutting & now the 12z has gone further still- I said the range was -2 to -9c this morning, maybe I should change the range to -1c ( due to UKMO) all the way up to -12c.

 

I have chipped the ECM 5% confidence tonight- this is due to the UKMO not yet being on board, if the GEM & JMA were close to the UKMO that would have been nearer 20%- but these 2 models underpin the ECM at the crucial timeframe- both also sending wedges of high pressure towards Svalbard with their respective 192 charts below

http://modeles.meteociel.fr/modeles/gem/runs/2014010612/gemnh-0-192.png?12 GEM

Discarded for now as the GEM develops another atlantic low that undercuts the high & heads towards the azores.

http://www.meteociel.fr/modeles/jma/runs/2014010612/JN192-21.GIF?06-12 JMA

A plausible outcome.

 

 

Onto the UKMO/ GFS which again is a blend of non amplified weather

 

UKMO 20% / GFS 20% confidence.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2014010612/gfsnh-0-144.png?12  GFS 144

http://www.meteociel.fr/ukmo/runs/2014010612/UN144-21.GIF?06-18 UKMO 144

 

 

The GFS appears to be on board now with ridging after days & days of never ending zonality, it is more amplified than the UKMO @ 144- & so goes on to develop the high pressure over Svalbard, however after this we encounter another GFS 'issues' which is its lack of ability to separate energy & generate undercutting- so any low pressures that do become attached & appear to want to undercut just go through the high-  hence its flattened.

We don't see what the UKMO 168 is like but the jury is out- possibly no link up.

 

The snippet of info from Ian F this morning was that the UKMO raw was heavily modified to the ECM's westerly solution.

 

 

Summary:

 

Despite the GFS fans I believe we are done & dusted with the wedge of heights & undercutting at around 156/162-  I think the UKMO & at some point the GFS will move back to the ECMs solution.

 

After that the undercutting can manifest in many different ways & theres where we should start to look at in terms of possible cold devlopments for the UK which includes the possibility of snow through a straddled front scenario.

 

Sorry if this offends the GFS fanboys, but the reality is that things have moved on since 2005 when GFS was thought to be king.... ECM rules the roost, the ONLY bias I can currently pin on it is the over estimation of blocking across Greenland- which I will build into future considerations when that type of pattern should occur again.....

 

CIAO

S

Edited January 6, 2014 by Steve Murr

[cooling climate]

How many times have we seen the ECM deliver the goods with a superb run and then to

back track on following runs although it did not quite make it on this run.

Taking into account the promising 12z GFS run you would be inclined to think the ECM

is on the money and by tomorrow it would be showing a full blown easterly but like a bad

toothache that won't go away you are reminded of the UKMO run.

[SMU]

http://www.emc.ncep.noaa.gov/gmb/STATS/html/new_acz6.html

 

Just to highlight the recent GFS performance - now in forth behind the GEM which is TOP!S 

[johnholmes]

http://www.emc.ncep.noaa.gov/gmb/STATS/html/new_acz6.html

 

Just to highlight the recent GFS performance - now in forth behind the GEM which is TOP!S 

 

UK M=top, not often that happens to ECMWF

[R.P. McMurphy]

http://www.emc.ncep.noaa.gov/gmb/STATS/html/new_acz6.html

 

Just to highlight the recent GFS performance - now in forth behind the GEM which is TOP!S 

 

No doubt about it Steve, coupled with your outrageously good post above, that chart speaks for itself, the GFS lately has fallen off the cliffe and cannot be trusted at all. Lets hope the revamp of it this year will also aid us in forecasting the future !

[Man With Beard]

Great post Steve, thanks! 

Since I remember last year that the ECM sometimes corrected east as T0 approached (and I think Steve picked up on this at the time), it will be interesting to see if there are corrections east in a few days - hopefully they will be the other way!!

For all the GFS criticism today, it should be given a little credit because (assuming it happens) it picked this pattern change out last Friday only to drop it within a few runs. Within T96-T192 I see GFS making mistakes quite often, but whenever a pattern change occurs it always seems to give us a preview somewhere in the T200s or T300s! So it has got its uses for me!!

[Zenarcher]

My view on the models this evening,

 

First the next 72 hours

 

24 hours Tuesday 7th

 

The deep low that brought wet and windy weather on Monday now moves North and it starts to rise in pressure.

 

 

It will be mainly a cloudy day with plenty of showers around and rain will move across the North. In the afternoon England and Wales look to be clear and sunny. Gale force winds will be from the South West for most of the UK. Max temp 12c and min temp 2c.

 

48 hours Wednesday 8th

 

Weak low pressure sits to the North of the UK but a small shallow low moves in over the South bringing some very wet weather.

 

 

The Northern half of the UK looks sunny, mostly dry and bright. For the Southern half it will be cloudy with rain moving in from the South West during the morning and afternoon. A strong breeze for most but gale force winds along Southern England during the evening. Max temp 12c and min temp 0c.

 

72 hours Thursday 9th

 

Weak low pressure to the North East of the UK but the pressure starts to rise slightly in the West.

 

 

Overall in general it's looking sunny for all of the UK I think many will be baffled by the rare bright and clear conditions. The wind will be breezy and max temp 11c and min temp 0c.

 

Now onto to comparing the GFS, ECM, UKMO, JMA, GEM and NAVGEM.

 

96 hours Friday 10th

 

The ECM along with the JMA, GEM and NAVGEM all develop a low in the Atlantic. The ECM and GEM look very similar but the rest it varies on the positioning and deepness.

 

 

The GFS and the UKMO don't show this although the GFS does go on to form a low much later on than the rest.

 

120 hours Saturday 11th

 

Two things to look at here first how much pressure from Europe builds up and reaches over the UK.

 

All of the models apart from GEM and the UKMO show pressure of 1015mb reach Southern Scotland.

 

 

Then there's GEM and the UKMO that have the pressure slightly below more South,

 

 

We want to get as much going North there like how the JMA shows for example it helps out later on.

 

Next the Atlantic low, every single model apart from the UKMO develops one in a very similar position. The only differences are how deep it is and how much high pressure is to the East. By comparing them side by side the JMA and GEM look the most similar.

 

 

144 hours Sunday 12th

 

The ECM, JMA, GEM and NAVGEM show a deep low to be situated near Iceland. Some of them have good heights building up to our North East as well. Some decent agreement here still very undecided at the moment though.

 

 

The GFS and UKMO once again are showing something different the GFS isn't too far off the rest though it does have a low around Iceland and heights over our North East but the UKMO looks like the odd one out here mainly flat weak pressure in the Atlantic and doesn't really show heights building up to the North East as much as the others.

 

 

Overall - Over the next few days the weather should slowly improve and temperatures overall are expected to drop slightly. Some sunny clear weather ahead as well. In the longer term for Friday into the weekend and next week is where it is uncertain. Most of the models this evening do show good runs for cold lovers out there after a horrible unsettled spell in December the charts this evening are some of the best of the winter. The GFS to me seems to be slowly getting similar to the ECM and some of the other models. The UKMO model this evening show's big disagreements amongst the rest of the charts. I personally do believe our chances of a colder spell of weather will increase as January progresses. I never got time to finish my winter forecast but I remember mid or late January was the time period for cold weather to arrive and remain into early February.

[Summer Sun]

ECM keeps high pressure to our east again this evening on its ensemble run

 

[Downpour]

The Korean long range model which was showing an easterly freeze for February, could be right after all. The models are moving in the right direction, but it remains only a hint that winter proper will arrive soon.   Enjoy the weather whilst you can mildies.

The Korean model?! Is it any good?

[Captain Shortwave]

The split jet is there to see on the ECM ens, as standard a mix of solutions depending on how much energy goes north east and south east, not surprising to see a rather smoothed over result for the bulk of Europe. 

All to play for. The UKMO currently looks an outlier solution. Had to be that model, it can be isolated at day 6 and trounce the other models, but can be wrong at even 2 days out from experience. Just something to shred peoples nerves

[Downpour]

Ithink if we look across all models plus the long range met office update the future is very interesting with possibly newsworthy weather to take us to the end of January .Colder air to our possibly east or n /east and an atlantic still breathing .but the end of this Month is 3 weeks away so no model as far as i know would have a clue , of  course met office are touting a possible cold spell at the end of this month probably going by their research involving upper atmosphere with new computer etc .So we need some good upgrades over coming days to go with tonights better charts .

Quite so Le Gritter. While I feel that the models have edged towards coldies' favour (the absence from Ian Brown from the forum also being telling) it's far from a confident move. That all said, what price a repeat of last winter - wet and wild until mid Jan then in the freezer until Easter? So long and cold was winter in London last year people seem to have forgotten that it was a real late developer.

[shaky]

Ecm mean looks very good!!once again just like this morning shows undercutting lows!!

[Gibby]

Good evening. Here is the report on the midday outputs from the NWP for today Monday January 6th 2014.

 

All models show a deep depression to the NW of the UK filling slowly over the next 48 hours as it moves slowly NE ending up to the North of Scotland by this time on Wednesday. In addition frontal rain will flirt with the South at times over the next 48 hours enhancing the flooding risk even further in the South. However, strong winds will become less of an issue with time with only moderate Westerly breezes by Thursday with some further rain running West to East across the UK. By the end of the week pressure will of risen strongly to the SE of the UK with drier and quieter weather likely for all for a time.

 

GFS through the weekend shows quiet and fine weather for many before the unsettled weather returns from the West early next week with rain bearing fronts crossing the UK from the West in what would be if verified another round of deep depressions, intensely so at the end of the run with strong to gale winds again and heavy rain and flooding issues likely again.

 

The GFS Ensembles look very unsettled and changeable again tonight with rain at times with strong winds too and little likelihood of much in the way of drier weather after the breather of later this week.

 

UKMO for next Sunday shows High pressure declining away SE early next week as troughs of Low pressure move in from the Atlantic with further unwanted rainfall following the drier interlude early in the weekend.

 

GEM shows an interesting period from next weekend as it's operational shows Low pressure moving in late next weekend with further rain before the whole system slides SE allowing pressure to rise strongly to the NW of Britain. This would enable winds to swing NE and Low pressure to reside near the Meditteranean with the cold wind giving rise to some wintry weather with snow in places in 10 days time.

 

NAVGEM declines High pressure away SE too after the weekend as Low pressure to the NW sends troughs back NE over the UK next week with renewed rain, this time probably heaviest towards more NW areas rather than places further South and east.

 

ECM tonight shows Saturday as the best day of this week when it should be dry and fine under a transient ridge of High pressure. It isn't long before Low pressure troughs swing back in from the West before sliding SE and giving rise to plenty of rain again in the process. then towards the end of the run a new Low over the Western Atlantic send another active trough slowly East across the UK hitting a High pressure block slowly declining across Europe.

 

The ECM 9 and 10 Day Mean Charts show strong signals for the majority of members of the ECM pack to favour a blocking High over Scandinavia at this time point with the UK lying in a SSE flow with Lower pressure troughs close to the West. If this majority verifies then we can look forward to some colder and drier weather but if the fronts to the West come in too close then we could all end up with a lot of cold rain and perhaps some snow.

 

http://www.wetterzentrale.de/pics/Reem2161.gif

http://www.wetterzentrale.de/pics/Reem2401.gif 

 

The GFS Jet Stream Forecast tonight shows the current flow imploding in a few days time before becoming diffuse and unclear with regard to favoured position before the pattern resets with an incredibly powerful surge of flow shown racing over the Atlantic towards the UK late in the run.

 

In Summary tonight the pattern is taking a backwards step towards maintaining rather unsettled weather moving into next week and beyond. The Atlantic is shown to weaken considerably later this week with at least a window of drier weather likely towards the weekend before it looks increasingly possible for wet and windy weather to return later though hopefully not to the extremes of recently. There is still a nugget of hope for cold lovers though as both GEM and ECM go for some trough disruption next week meaning an awful lot of cold rain for many as Low pressure slides SE and opens the door to something rather colder behind it ala GEM. However, despite the principal being the same from ECM the Atlantic proves too strong from this run to set up cold Easterlies as the next Low pushes troughs back in from the West on Day 10.