Model Output Discussion - 10th Jan Onwards

[draztik]

Like the op runs this morning, the ensembles seem to be dancing to the same tune. The ext ecm ens are noticeably poor today, with the 6-10 day heights showing troughing over the southern UK into western Europe, so it appears winds will alternate between a westerly and NW flow - which will keep temps below average.

6-10 day heights

Ita longer term outlook shifts the mean troughing to our shores & to our nw .. temps look like remaining below average, but nothing overly so. So ecm very keen on a more mobile, zonal flow.

Days 10,13,15 height anomalies ecm ext.

The Canadian ens at day 10 & 15,

Don't really need to say much, as the graphics do the talking...

And the Teleconnections, don't offer us much hope, with a pna forecast to turn sharply negative during last third of month, and an nao remaining positive throughout.

Even with the above, it would be foolish to completely write off January. Models have shown to be fickle, but the odds are stacked against anything cold or settled this morning.

[Blizzardof82]

I really hope this comes to fruition and with each run get's closer and stronger

 

The strat warming has been at 300 plus hours for the last fortnight.

[ukpaul]

The strat warming has been at 300 plus hours for the last fortnight.

There have been a number of warming events at t0 in the last fortnight, the pv being so strong means that it has, and will take, yet more before it affects the trop. It is notably weaker now (and, given the time of year will also weaken further).

[Nick F]

The pattern looks rather stuck in the medium to longer term unfortunately, which gets us no where nearer to cold and wintry prospects. You only have to look upstream on the models over N America, where the limpet lobe of the PV stuck over NE Canada means a deep long-wave trough will persist over the eastern 2/3 of the US, while the +ve PNA pattern continues the ridge over western US. With the low heights persisting close to the NW and blocking to the NE fairly weak, it appears inevitable that upper flow energy over the Atlantic will mean the flow will prove too progressive for any trough disruption now to bring an easterly. So probably best to put the final nails in the coffin for that idea.

 

Having a read through some of the upper atmosphere forecasts, there does seem to be a signal for an upward propagating Rossby Wave over the E Pacific to take a hit on the Polar Vortex, which may initiate stratospheric warming. The occurence of this is still some way off on the ECMWF and NAEFS output, and there's then the question of whether it'll work its way down into the Troposphere. If it does, then ultimately we are looking at a potential change to the Northern Hemisphere's weather and teleconnection patterns during February. No guarantees of course that our fortunes will change next month.

 

For now, with the PNA+, persitent PV over N Canada and the MJO weak and going nowhere, there seems little impetus to change the pattern upstream and thus our cold and snowy fortunes looking fairly poor for us, for now. The best we can hope for is some transitional snow events and frosts in the the northwesterly flow, once the block to the NE clears east. Snow chances best for northern Britain and mostly to higher ground. Unfortunately the progressive pattern means more rain, but with a flow W or NW rather than SW, perhaps less rainfall than December.

Edited January 15, 2014 by Nick F

[Purga]

Strong very cold & powerful PV in its favourite location with the azores HP displaced east and strong to the south of us continues on and on.

 

A wretched setup for cold as ever.

Edited January 15, 2014 by Purga

[nick sussex]

Thanks Draztik for putting up those charts, your first map clearly highlights the problem with continued lower heights attached to the troughing  near the UK.

 

We do however have to be a bit guarded in terms of looking weeks ahead because of some uncertainty in the USA, generally they are happy with their forecast with one proviso:

 

TELECONNECTIONS UPON THE MAJOR HEIGHT ANOMALY CENTERS (WEST COAST, EASTERN CONUS, NORTH ATLANTIC) SUGGEST THE FORECAST WAVE PATTERN MAY CONTAIN WAVELENGTHS THAT ARE TOO LARGE GIVEN THE POTENTIAL AMPLITUDE OF THE PATTERN. THIS INCREASES UNCERTAINTY, ESPECIALLY IN THE PRECIPITATION FORECAST, WHERE SHORTWAVE AMPLIFICATION SEEMS LIKELY DURING THE WEEK-2 PERIOD, THOUGH IT'S UNCERTAIN WHEN IT WILL OCCUR. CONFIDENCE IS FAIRLY HIGH THAT ANY AMPLIFICATION WOULD OCCUR IN THE EASTERN HALF OF THE CONUS; NEAR-MEDIAN PRECIPITATION IS FAVORED ALONG THE EAST COAST AS A RESULT. ABOVE-MEDIAN PRECIPITATION IS FAVORED FROM THE CLIMATOLOGICALLY-DRY NORTHERN PLAINS, WHERE MULTIPLE SHORTWAVES ENTERING THE MEAN TROUGH ARE LIKELY TO CAUSE SOME SNOWFALL, TO NEW ENGLAND, WHERE ANY STORM TRACKS ARE FAVORED TO CONVERGE.

 

At this stage we don't know exactly when that amplification will occur upstream and this does have an impact on the amount of energy spilling east, with blocking still evident to the ne we may well be seeing trough uncertainty part 2.

[Purga]

Thanks Draztik for putting up those charts, your first map clearly highlights the problem with continued lower heights attached to the troughing  near the UK.

 

We do however have to be a bit guarded in terms of looking weeks ahead because of some uncertainty in the USA, generally they are happy with their forecast with one proviso:

 

TELECONNECTIONS UPON THE MAJOR HEIGHT ANOMALY CENTERS (WEST COAST, EASTERN 

CONUS, NORTH ATLANTIC) SUGGEST THE FORECAST WAVE PATTERN MAY CONTAIN 

WAVELENGTHS THAT ARE TOO LARGE GIVEN THE POTENTIAL AMPLITUDE OF THE PATTERN. 

THIS INCREASES UNCERTAINTY, ESPECIALLY IN THE PRECIPITATION FORECAST, WHERE 

SHORTWAVE AMPLIFICATION SEEMS LIKELY DURING THE WEEK-2 PERIOD, THOUGH IT'S 

UNCERTAIN WHEN IT WILL OCCUR. CONFIDENCE IS FAIRLY HIGH THAT ANY AMPLIFICATION 

WOULD OCCUR IN THE EASTERN HALF OF THE CONUS; NEAR-MEDIAN PRECIPITATION IS 

FAVORED ALONG THE EAST COAST AS A RESULT. ABOVE-MEDIAN PRECIPITATION IS FAVORED 

FROM THE CLIMATOLOGICALLY-DRY NORTHERN PLAINS, WHERE MULTIPLE SHORTWAVES 

ENTERING THE MEAN TROUGH ARE LIKELY TO CAUSE SOME SNOWFALL, TO NEW ENGLAND, 

WHERE ANY STORM TRACKS ARE FAVORED TO CONVERGE.

 

At this stage we don't know exactly when that amplification will occur upstream and this does have an impact on the amount of energy spilling east, with blocking still evident to the ne we may well be seeing trough uncertainty part 2.

Thanks for that Nick - will your nerves be able to take another onslaught?

[johnholmes]

The pattern looks rather stuck in the medium to longer term unfortunately, which gets us no where nearer to cold and wintry prospects. You only have to look upstream on the models over N America, where the limpet lobe of the PV stuck over NE Canada means a deep long-wave trough will persist over the eastern 2/3 of the US, while the +ve PNA pattern continues the ridge over western US. With the low heights persisting close to the NW and blocking to the NE fairly weak, it appears inevitable that upper flow energy over the Atlantic will mean the flow will prove too progressive for any trough disruption now to bring an easterly. So probably best to put the final nails in the coffin for that idea.

 

Having a read through some of the upper atmosphere forecasts, there does seem to be a signal for an upward propagating Rossby Wave over the E Pacific to take a hit on the Polar Vortex, which may initiate stratospheric warming. The occurence of this is still some way off on the ECMWF and NAEFS output, and there's then the question of whether it'll work its way down into the Troposphere. If it does, then ultimately we are looking at a potential change to the Northern Hemisphere's weather and teleconnection patterns during February. No guarantees of course that our fortunes will change next month.

 

For now, with the PNA+, persitent PV over N Canada and the MJO weak and going nowhere, there seems little impetus to change the pattern upstream and thus our cold and snowy fortunes looking fairly poor for us, for now. The best we can hope for is some transitional snow events and frosts in the the northwesterly flow, once the block to the NE clears east. Snow chances best for northern Britain and mostly to higher ground. Unfortunately the progressive pattern means more rain, but with a flow W or NW rather than SW, perhaps less rainfall than December.

No apologies for repeating the whole of the post by Nick F

The most realistic post I have read this morning, short, medium and longer term, say out towards the end of January.

[Geordiesnow]

Apart from a brief flirtation, it ashame the blocking does not look like it will affect our weather but its only the weather so can't complain about it really. 

 

The outlook looks a bit bland in fairness, however winter is far from over and change could always occur any second, as Nick says, the likely source for cold air will be from the North West you would imagine. 

 

That said, we still got February and March as shown last year can be a wintry month also so still time to get our first widespread lying snow of the season! 

[mcweather]

No apologies for repeating the whole of the post by Nick F

The most realistic post I have read this morning, short, medium and longer term, say out towards the end of January. 

 

Good post John. We can all hope for what we might like to see but if its not being consistently shown in the models ( especially short to medium term) then it is unlikely to appear.  I would love the briefly shown easterly to come off but the vast majority of the modelling says no, so its unlikely.

 

However we still have February to to look forward to.

[Timmytour]

All these hints and flirtations that lead nowhere......sooner or later the Beast will realise that it needs more than these to get the UK Beauty to fall under its spell.  There's gonna have be chocolates and flowers soon followed by the promise of jewellery if it doesn't want the UK to knuckle down and spend her winter with the boring and dull but dependable Atlantic.


For me, the following chart shows the system that will bring most of us our first snow of the winter......only come 26th Jan it won't be positioned over the north east of scotland as currently projected to be and the cold air to the east will be a lot deeper and more extensive...

[492]

The broad scale features may well support progression in the longer term but we still have to negotiate the trough which is expected to disrupt in the short and medium term close to or over the UK. Pressure falls are expected over the western Med which would help to support the high which is currently taking shape over and to the NW Scandiavia. Following the disruption and looking at some of the recent output I would have thought that a period of quieter, colder weather perhaps with a gentle NE'y flow at least in the SE in still on the cards and which may just hang on a little longer than is currently expected.   

[North-Easterly Blast]

Strong very cold & powerful PV in its favourite location with the azores HP displaced east and strong to the south of us continues on and on.

 

A wretched setup for cold as ever.

If we have to have zonality, just why can't it be cold zonal:

 

http://176.31.229.228/modeles/reana/1984/archivesnh-1984-1-15-0-0.png

http://176.31.229.228/modeles/reana/1984/archivesnh-1984-1-16-0-0.png

 

Strong polar vortex to the north, HP way too far north to influence the UK with cold, but guess what, heavy snowfall in a zonal setup that lay on the ground for up to a week even at low levels, also a little snow further south too:

 

http://176.31.229.228/modeles/reana/1984/archivesnh-1984-1-23-0-0.png

http://176.31.229.228/modeles/reana/1984/archivesnh-1984-1-24-0-0.png

http://176.31.229.228/modeles/reana/1984/archivesnh-1984-1-26-0-0.png

 

 

I hate mild zonality in the UK, and to me is the worst weather in our climate that exists and ever occurs.  Why can it not give us a cold zonal setup, and be polar maritime zonal, and at least ber cold enough for snow over northern parts at least.  The above charts just shows what is possible in a favourably orientated zonal flow NW-SE, but why doesen't it happen and so rarely happen?  It seems to happen more for Scotland, but rarely so south of the Border, and in a zonal flow the UK seems to be around 1000 miles too far south to see cold zonality.  Areas between north Scotland and Iceland see it in most zonal setups, but why does it just not happen far south enough for the UK as the above charts show?

Edited January 15, 2014 by North-Easterly Blast

[shedhead]

Rather depressingly today is day one of the second half of official Winter and it finds most of us still awaiting the first snowflake and some of us even still awaiting the first air frost, so I guess the glass half full view must be that things can only get better...hopefully. 

 

As Nick F's excellent post said however prospects for the next week or so and perhaps even the remainder or Jan do not look encouraging as far a deep cold is concerned, with only enough minor changes in the overall pattern to slow and weaken the hiterto raging Atlantic train, rather than fully derail it.  GFS does again look rather to progressive with it's return to a flatter pattern next week, but using recent longer term charts as a guide ECM could again be introducing to much amplification to the pattern, with something of a half way house blend probably being how things will end up later next week.

 

Beyond that we are getting dangerously close to the start of Feb and the last third of official winter, so we really do need to see some tangible signs of a proper and sustainable pattern change across the next couple of weeks if winter 2013/2014 is not to be remembered for all the wrong reasons...well at least as far as this place is concerned!  

Edited January 15, 2014 by shedhead

[lassie23]

Rather depressingly today is day one of the second half of official Winter and it finds most of us still awaiting the first snowflake and some of us even still awaiting the first air frost, so I guess the glass half full view must be that things can only get better...hopefully. 

 

As Nick F's excellent post said however prospects for the next week or so and perhaps even the remainder or Jan do not look encouraging as far a deep cold is concerned, with only enough minor changes in the overall pattern to slow and weaken the hiterto raging Atlantic train, rather than fully derail it.  GFS does again look rather to progressive with it's return to a flatter pattern next week, but using recent longer term charts as a guide ECM could again be introducing to much amplification to the pattern, with something of a half way house blend probably being how things will end up later next week.

 

Beyond that we are getting dangerously close to the start of Feb and the last third of official winter, so we really do need to see some tangible signs of a proper and sustainable pattern change across the next couple of weeks if winter 2013/2014 is not to be remembered for all the wrong reasons...well at least as far as this place is concerned!  

Since I have been on this forum, which hasn't been long, people including myself, have been saying cold is on the way, it should be snowing by 16th January, the ECM looks amazing, even though it has always been wrong etc etc etc. The fact of the matter is that the GFS is calling the shots this winter and it does matter what is happening in the US this winter too. Until the GFS starts showing cold CONSISTENTLY and the vortex is weakened, halting all that cold air flowing into the north atlantic, we are stuck with mild atlantic driven boredom. 

[johnholmes]

Since I have been on this forum, which hasn't been long, people including myself, have been saying cold is on the way, it should be snowing by 16th January, the ECM looks amazing, even though it has always been wrong etc etc etc. The fact of the matter is that the GFS is calling the shots this winter and it does matter what is happening in the US this winter too. Until the GFS starts showing cold CONSISTENTLY and the vortex is weakened, halting all that cold air flowing into the north atlantic, we are stuck with mild atlantic driven boredom. 

 

I am not sure why you suggest that ECMWF is wrong as you quote

even though it has always been wrong etc etc etc. 

 

This is untrue at least at 500mb on the checks done daily by NOAA, see link below

http://www.emc.ncep.noaa.gov/gmb/STATS/html/new_acz6.html for the northern hemisphere at day 5 and day 6.

 

To me it seems unlikely that even in this tiny portion of the hemisphere that GFS is so much better than ECMWF. The statistics show it routinely behind both ECMWF and UK Met. Of course it got it wrong about the easterly but then GFS was not that brilliant in guidance at times.

 

To get a sense of what is the most likely outlook be it 24 hours or for much longer time scales then one has to look at all the output available, check for consistency and then make an assessment of what is the most likely to be nearest the actual weather.

Edited January 15, 2014 by johnholmes

[IDO]

Since I have been on this forum, which hasn't been long, people including myself, have been saying cold is on the way, it should be snowing by 16th January, the ECM looks amazing, even though it has always been wrong etc etc etc. The fact of the matter is that the GFS is calling the shots this winter and it does matter what is happening in the US this winter too. Until the GFS starts showing cold CONSISTENTLY and the vortex is weakened, halting all that cold air flowing into the north atlantic, we are stuck with mild atlantic driven boredom. 

 

 

Yes I agree some replies on here are that we can still get cold if it is cold in America; of course that is correct, but IMHO, when there is no blocking, as in this current Winter, then there is only so much cold to go around. If our friends in the USA are getting most of it along with Siberia, then the UK is just getting the odd lucky PM or AM flow.

 

And yes the ECM has been very disappointing with its promises of cold that are just a computer's imagination gone wild. I don't care that ECM nails the 500 upper flow better than GFS, who cares, it is when it matters, when cold may be on the horizon that we need it to verify, and it has sucked this Winter.

 

Not the only ones to think that:

 

  Hudsonweather

Little signal for winter in January. ECMWF has given unusually poor guidance. GFS surprisingly good, most consistent in not wanting cold.

15/01/2014 13:32

 

Looking like we are relying on a SSW to save the Winter; the warmings, the first which has now penetrated to the trop. appears to be rather tame: cooler, yes but nothing wintry. Other warmings to come, but again with a PV dominated winter they may simply not amount to much. Some pros wishy washy about an SSW:

 

  _chrisfawkes

.@MattHugo81 Sadly can't see any evidence of SSW. The PV looks quite happy to end of Jan in GFS & EC. Last attacks failed to break PV

15/01/2014 14:31

 

Yes still a month of Winter to come and March as well so chances of some cold, but a prolonged cold spell, optimism is very low...

 

...unless you live in the USA that is!

[Yarmy]

Here's a challenge: what's the most recent chart showing a 500hPa geopotential height of greater than or equal to 5440 metres anywhere over Greenland (i.e green on the meteociel scale)?

 

This is the best I could do:

 

 

Didn't last long either!

 

 

All eyes on the Strat.

Edited January 15, 2014 by Yarmy

[Kentspur]

Apart from a brief flirtation, it ashame the blocking does not look like it will affect our weather but its only the weather so can't complain about it really. The outlook looks a bit bland in fairness, however winter is far from over and change could always occur any second, as Nick says, the likely source for cold air will be from the North West you would imagine. That said, we still got February and March as shown last year can be a wintry month also so still time to get our first widespread lying snow of the season!

Let's not forget that March was the coldest month of 2013! Down here in the southeast apart from one notable snowfall which didn't occur until 21St January we had to wait until April to see another heavy prolonged snowfall- albeit wet slushy deposits in London. Experience tells me we're far from out of the cold/ snowy woods just yet if last year's anything to go byFingers crossed the next warming of the stratosphere blasts the p v to somewhere else Edited January 15, 2014 by Kentspur

[UV-RAY]

Yes I agree some replies on here are that we can still get cold if it is cold in America; of course that is correct, but IMHO, when there is no blocking, as in this current Winter, then there is only so much cold to go around. If our friends in the USA are getting most of it along with Siberia, then the UK is just getting the odd lucky PM or AM flow.

 

And yes the ECM has been very disappointing with its promises of cold that are just a computer's imagination gone wild. I don't care that ECM nails the 500 upper flow better than GFS, who cares, it is when it matters, when cold may be on the horizon that we need it to verify, and it has sucked this Winter.

 

Not the only ones to think that:

 

  Hudsonweather

Little signal for winter in January. ECMWF has given unusually poor guidance. GFS surprisingly good, most consistent in not wanting cold.

15/01/2014 13:32

 

Looking like we are relying on a SSW to save the Winter; the warmings, the first which has now penetrated to the trop. appears to be rather tame: cooler, yes but nothing wintry. Other warmings to come, but again with a PV dominated winter they may simply not amount to much. Some pros wishy washy about an SSW:

 

  _chrisfawkes

.@MattHugo81 Sadly can't see any evidence of SSW. The PV looks quite happy to end of Jan in GFS & EC. Last attacks failed to break PV

15/01/2014 14:31

 

Yes still a month of Winter to come and March as well so chances of some cold, but a prolonged cold spell, optimism is very low...

 

...unless you live in the USA that is!

Sadly I feel those confidence levels will bear true and the best we can hope for will be Northerly topplers and probably a MLB  towards the second half of next month. Nothing in any of the model output to be positive about if it's cold your looking for anytime soon in England and Wales. Some colder PM air for Scotland at times which will bring some wintry weather to lower elevations up  there, but the rest of us, well the same old tumbleweed blowing across the output.

[johnholmes]

 

 

I could be totally brutal and say perhaps some of you may now begin to see the folly of watching the synoptic models for the weather without checking on other outputs. Hurtful no doubt but true. I could show you every single output from Ec-gfs and noaa 500mb anomaly charts for the last 10 -15 days if you like to prove my point. On only ONE day, 5 January did ec suggest this along with noaa, but not gfs, that is  the 'possibility' of a Scandinavian block. Nothing before and nothing since. Why do you think Exeter never went for it, I have no idea if they use the anomaly charts but they must have seen how isolated the risk was from whatever their sources thus never went for it. Loud cries on here that they were wrong and they would change because of the synoptic outputs etc.

Like I say it is a harsh comment for you and others but it is true. No major upper air pattern except for that one day ever seriously suggested an easterly.

Yes I got sucked in to the extent I went from sitting on the fence with a prob of no more than 40% to on the one day being totally over ruled by my heart (I am a snow lover) and edging it above 50%, but then brain took over and I dropped the idea.

Edited January 15, 2014 by johnholmes

[phil nw.]

I think quite a number of us who have been model watching for a number of years had our interest raised on that modeled block to the ne, during the last week or so.

I guess that's what this thread is for to ponder the chances which were at one point finely balanced on whether the block would develop into something.

I was never convinced on the evolution to a full on easterly although i was looking at the chance of the block holding at least for a while giving perhaps frontal snow to the east of approaching systems as they disrupted against a colder se flow.

With little interest for the majority in here so far this Winter then it has at least given folks something a little different to talk about other than the relentless westerlies we have had so far this Winter.

Anyway all current outputs seem to push the overall pattern too far east  so it looks likely further lows from the Atlantic will be affecting us over the next week to 10 days.

Let's see what the 12z outputs show anyway.

[frosty ground]

 

that Low of north western Spain is a new feature..... 

[Staffordshire]

 

that Low of north western Spain is a new feature.....

encouraging sign as it may help to drag the lows to it's NW down towards it let's see how the other models show this.

[Cecil Hogmanay Melchett]

WOW-

Only 2 posts on the GFS12Z? That probably speaks volumes about the apathy we are all feeling now,and who can blame us?

 

FWIW the 12z going exactly the same way the previous 06z run went with zonal dross on the menu for the forseeable.

Im of the opinion any cold shot will come from the North west at some point,simply becasue the scandy high is going to end up somewhere in Western Russia by the time January closes!!