WInter Model Output Discussion 12z- 28/01/2013

[Jason M]

I'm not too fussed about the GFS opp run in FI. It actually runs at lower res than the ensembles after 192 hours so with a decent broadscale agreement out to days 6/7 the ensembles are of more interest. In isolation they are not bad, they are just less good IMO than the last few sets. Over the last 48 hours we have not seen the better set ups moving through the time periods. The best stuff remains out beyond 10 days.

Whatever happens this winter has been odd really. Other than the obvious horror winters such as 1988 the sheer persistence of low heights to our NW has been amazing really. Even now the PV looks like sticking near Greenland.

Don't get me wrong, we still have a shout but I just feel this morning that the odds have reduced.

Jason

[nick sussex]

We have to accept that the Azores high is determined to play a key role for the foreseeable future.

I don't see a clear signal to develop Greenland high pressure within the next ten days so its really the movement of the Azores high that will dictate the flow into the UK and western Europe.

If you can get this far enough west and north then any low pressure travelling around the peripheries can bring some wintry weather but you're always liable to have warmer sectors occasionally effecting some parts of the UK.

The general idea of low heights developing in central Europe looks solid so this precludes any milder spells but as for deep cold I don't really see this without a pressure rise to the ne or pressure rising over Greenland.

So I think its looking like a mixed bag of conditions with everything thrown in for the timebeing.

In the shorter term still uncertainty for the weekend with the ECM progging that deep low whereas both the GFS and UKMO don't, unusual to see the ECM doing this, you'd expect this more of the GFS.

The outlook could of course be worse at least there is some wintry potential in the outlook but at the moment not perhaps the deep cold and longer lasting snow that most people in here want to see.

Edited January 29, 2013 by nick sussex

[UV-RAY]

We have to accept that the Azores high is determined to play a key role for the foreseeable future.

I don't see a clear signal to develop Greenland high pressure within the next ten days so its really the movement of the Azores high that will dictate the flow into the UK and western Europe.

If you can get this far enough west and north then any low pressure travelling around the peripheries can bring some wintry weather but you're always liable to have warmer sectors occasionally effecting some parts of the UK.

The general idea of low heights developing in central Europe looks solid so this precludes any milder spells but as for deep cold I don't really see this without a pressure rise to the ne or pressure rising over Greenland.

So I think its looking like a mixed bag of conditions with everything thrown in for the timebeing.

In the shorter term still uncertainty for the weekend with the ECM progging that deep low whereas both the GFS and UKMO don't, unusual to see the ECM doing this, you'd expect this more of the GFS.

The outlook could of course be worse at least there is some wintry potential in the outlook but at the moment not perhaps the deep cold and longer lasting snow that most people in here want to see.

A well balanced post Nick and I think your suggestion of the Azores high being in a favourable position is the only straw we can clutch for the next 10-14 days, beyond that who knows, but the clock is ticking for anyone looking for deep cold.

[bluearmy]

Good ecm ens mean. Btw, ignore fi gfs - wrong

[Catacol]

Outlook for any cold still slow to develop on the models. In essence a north westerly air stream remains on the cards - no sign of anything biting from the east or north east yet. 2 charts as evidence. CPC 8 - 14 day first, now out as far as Feb 11:

Notice that the HP anomaly in the atlantic which has been signalled as developing for a few days now is not suggesting any great northward migration. Anomaly over Greenland is relatively slight - toppler territory this, or stationary mid atlantic high at best.

ECM mean still supporting this scenario too at 10 days:

A lot of energy still over Canada and azores pressure significant.

There are a lot of people convinced that something is going to pop up soon, but we are starting to get towards mid February in the outlook now, and cool but not cold is what the models are saying. Vortex energy over Canada still ruling the roost. Until it moves (some suggestion of that on ECM op at 240 this morning...) we are stuck for the most part.

[nick sussex]

A well balanced post Nick and I think your suggestion of the Azores high being in a favourable position is the only straw we can clutch for the next 10-14 days, beyond that who knows, but the clock is ticking for anyone looking for deep cold.

Thanks.

I agree it really has to come down to the Azores high and NOAA suggested some retrogression in the pattern which helps matters.

We do need to see more of a streamlined Azores high and not something which resembles my waistline!!! round and bloated!

Round and bloated the cold goes se, we need to see the cold going south through the UK. Overall todays output is neither great nor bad its sufficient to have a chance of some wintry weather and thats at least a positive.

We'll see in the coming days whether the models play with perhaps a high pressure wedge to the ne, I think theres more chance of that at the moment than a Greenland high.

[bradymk]

ECM means are impressive, deep trough in Europe with good support for an atlantic ridge moving northwards and westwards. It is a lot harder to get milder weather in the UK when you have this deep trough/low heights over the continent.

[Frosty.]

The cold snap on saturday looks to have upgraded with heavy wintry showers pushing south followed by a frost but during sunday the winds back westerly from the atlantic again and temps rise to around average by sunday pm but then it's all change again next week with a stronger polar maritime blast with gales and wintry showers once the band of rain has cleared through, then another brief less cold interval followed by another NWly blast, this time more potent than the previous two but just for now the gfs and ecm op runs are lacking the true arctic blast from yesterday but they could come back, the gfs 00z in FI almost brings the uk a link up with a scandi high but it fails this time, however, there is plenty of time for the outlook to change to something a lot more wintry.

[Cecil Hogmanay Melchett]

Really frustrating output for coldies with the godawful profile to the North west continuing unabaited,we have the low pressure over se europe and the azores high is showing the classic pre cold spells by moving west and north towards greenland BUT the jet just will not play ball for a true deep cold shot as heights continue to be low(grreny) and the conveyor of lows crashing off the eastern seaboard will prevent the link we need.

For scotland and parts of the north i would suggest wintry weather is posible over the next week or two,for those in the south id say its a poor outlook.

[bradymk]

Really frustrating output for coldies with the godawful profile to the North west continuing unabaited,we have the low pressure over se europe and the azores high is showing the classic pre cold spells by moving west and north towards greenland BUT the jet just will not play ball for a true deep cold shot as heights continue to be low(grreny) and the conveyor of lows crashing off the eastern seaboard will prevent the link we need.

For scotland and parts of the north i would suggest wintry weather is posible over the next week or two,for those in the south id say its a poor outlook.

you must of only looked at GFS 00z happy days, ECM, GEFS and ECM means all suggest a strong mid atlantic ridge retrogressing with a deep euro trough. Maybe not the "deep" cold pattern some would like to desire but a cold pattern which can certainly become much colder Edited January 29, 2013 by bradythemole

[Gibby]

Good morning folks. Here is this morning's look at the 00z Output from GFS, UKMO, GEM and ECM for today Tuesday January 29th 2013.

All models show a unsettled spell as we move through the rest of this week. The basic pattern of West or SW winds between various Low pressures crossing close to the North of the UK and High well to the South remains until Friday with rain at times in strong and relatively mild winds, especially today mixed with cooler and more showery interludes. On Friday an active Low develops and crosses more Southern Britain with some considerable rainfall and possibly some sleet and hill snow as it engages some colder air on its Northern flank as it moves away East by Saturday. Some wintry showers on a cold Northerly wind looks likely on Saturday especially in the East as pressure builds from the NW with a ridge toppling SE over Britain late in the day followed by a warm front moving slowly East over the UK and bringing a return to milder Atlantic Westerly winds and occasional rain to end the weekend..

GFS then shows a pattern of High pressure to the SW and Low pressure areas tracking SE to the NE of Britain. Successive cold fronts will introduce spells of rather cold and showery conditions to the North and East of the UK while the South and West of Britain see only limited coolness and mostly dry weather from these as High pressure remains closer to these parts. The North, Northwest and East would no doubt see wintry showers at times while the South and West stays mostly dry and rather cloudy with short milder incursions for all as warm fronts move gently East between the pushes of colder air. Late in the run pressure builds over the UK with frosty and rather cold conditions developing for all away from the far NW.

The GFS Ensembles show a huge spread between members generally from between +5C to -5C through the second half of its output this morning. The general shift to something slightly colder than currently remains but with no sign of any sustained and marked cold pattern. Rainfall becomes limited for most areas away from the North with European locations benefiting more from the cold pool associated with SE moving depressions rather than the UK.

The Jet Stream shows the flow ridging North over the weekend around a very dominant Azores Anticyclone and down across the UK early next week suppressing any Northward movement of the High and keeping the synoptics in a static pattern.

UKMO for midnight on Monday shows a broad WNW flow over the UK with a warm front having moved East over the UK with a cloudy and generally mild flow keeping Western hills and coasts rather misty and drizzly.

GEM is much more bullish about keeping SE moving Low pressures more influential to all of the UK with rather cold or cold NW winds bringing spells of wintry showers mixed with short milder interludes as warm fronts cross around the High out to the SW with rain and sleet on the boundary edge as they move East.

ECM finally shows a spell of NW winds with rather cold conditions in the North and Northeast with wintry showers with more Southern and Western areas more cloudy and less cold with just a little occasional rain. Late in its run cold Northerly winds plunge South through the UK as a deeper Low moves down into Europe though once more it looks unsustainable as warmer air waiting to the West looks likely to topple SE in the following days.

In Summary this morning some folks in the North and East of the UK may like this morning's output as here there will be quite a lot of rather cold and unstable air around giving lengthy spells of wintry showers and perhaps some boundary snowfall as warmer air migrates East at times. Further South and West will see rather less cold conditions with High pressure close to the SW keeping fronts weak and modified as they move across at intervals giving rather cloudy and benign conditions with just a little rain at times. There is little sign of anything substantially cold an a UK wide basis this morning with the Ensembles from GFS looking less exciting today.

[BLAST FROM THE PAST]

I think that we will see a return to very mild SW'lies to dominate February and that winter 2012/3 has been ok but is over now. I hope you enjoyed.

Might as well say it, that's all I'm reading at the moment.

BFTP

[ForeverPomeroysnow]

Hope u have your tin hat on BFTP

[Bristawl Si]

To my untrained eyes the weather outlook seems to be entering final phase of winter with a typically mixed bag of all weather types.

Possibly a gradual morph over the coming weeks from winter to spring.

[Severe Siberian icy blast]

A few things need to be said .

The Azores high is setting up shop to the west of uk, not northwest, and certainly NOT towards greenlands, the charts have northerly topplers written all over them.

The Canadian vortex is too much of a feature , even in deep fi and no heights will build toward Greenland with this the case.

We was told with a certainty the downwelling from the SSW would have its impact on or just after 28ths jan, this has not happened.

The SSW had an initial impact on us With a rapid response . If it wasn't for that we would all be going mad.

The topplers now coming into the forecasts have absolutely nothing to do with the SSW.

Either the models are about to a massive flip and recognise this downwelling and show signs of northerly blocking or . . .

Is not going to happen, and looking for cold for the 10th feb is nearly half way through the month and 13days late so can what happens then be down to the downwelling or just a typical February ?

Personly I think if we don't see a model flip in the next 4 days , and by a flip I mean obvious signs of a SSW affect , then certain ones including myself need to take a step back with the strat and recognise its a science in its VERY EARLY stages and accept its pattern of behaviour can be sporadic and unreliable .

I say this because GP has been so certain with his predictions but yet this year hasn't gone to plan as of yet. If it wasn't for the rapid response then this winter would have been one of the worst in living memory .

Not digging at anyone, just saying it as I see it.

Shaun.

[winterof79]

A well balanced post Nick and I think your suggestion of the Azores high being in a favourable position is the only straw we can clutch for the next 10-14 days, beyond that who knows, but the clock is ticking for anyone looking for deep cold.

Who is looking for a Greeny high all the time.Not me,we have just had a two week cold spell without one.

If ECM is to be believed there is plenty to please never mind your straw clutching and clock ticking stuff.. http://www.meteociel.fr/modeles/ecmwf/runs/2013012900/ECH1-96.GIF

http://www.meteociel.fr/modeles/ecmwf/runs/2013012900/ECH1-168.GIF?29-12 N/Westerly in yby http://www.meteociel.fr/modeles/ecmwf/runs/2013012900/ECH0-168.GIF?29-12 nice 850s

And this to finish BY day 10 http://www.meteociel.fr/modeles/ecmwf/runs/2013012900/ECH1-240.GIF?29-12

There is more to clutch at in ONE run than in many previos winters.

GFS ensembles look fine too and people would have gladly accepted these through the years http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

[Severe Siberian icy blast]

I think that we will see a return to very mild SW'lies to dominate February and that winter 2012/3 has been ok but is over now. I hope you enjoyed.

Might as well say it, that's all I'm reading at the moment.

BFTP

I am very happy with progress, and I am very happy to maintain Feb being the coldest month by a long shot...in this descending winter. Interesting to see ECM bring that nasty feature for Friday again. One to watch.

BFTP

BFTP as you can see you have just done the biggest contradiction in the universe can I ask why ?!!

Im disappointed this morning also , but 10 hours ago and all year in fact you have gone on about this feb been the month , and now you say this will be dominated by southwesterlies ?!

Is there reasons behind this or just feeling a bit emotional this morning like others ?!

Edited January 29, 2013 by Severe Siberian icy blast

[Jason M]

I think that we will see a return to very mild SW'lies to dominate February and that winter 2012/3 has been ok but is over now. I hope you enjoyed.

Might as well say it, that's all I'm reading at the moment.

BFTP

Then you might want to have another read through

From where we are this morning if someone was predicting the outrun from Feb, I'd say its looking like a below average month but not more in the rather cold than very cold category.

The trouble with a closed Azures high is that its essentially a modified zonal set up with the jet moving around the top of the high. The main difference being that were alternating rTM air with PM or modified arctic airmasses. It wont be warm (except in the numerous brief warm sectors).

Still interest in the ensembles and ECM isnt the worst tbh.

Jason

Jason

[full_frontal_occlusion]

A week ago during the major snow events, everyone was gnashing and wailing because all the models showed nothing but the Atlantic train-ride. SSW's were consigned to the scrap heap as being unpredictable on their affects for (cold-lovers) favourable positioning of the fragmented Polar Vortex. Predictions by some of the most respected members on NW.tv were trashed as being unreliable and new-fangled mathematical hocus-pocus with the rest of winter consigned to the bin.

The snow is gone and the Atlantic has indeed powered up, but the models for several runs now, have shown tentative signs of cold returning form the North.

Still in FI, but the trend is nonetheless there.

As always, the outcome will only start to become apparent when the steady-state features (blocking patterns, high pressure anchors etc.) enter into to higher resolution parts of the model run.

And as we all know (or should know by now) the very real stratospheric events take time to propagate and influence the troposphere. That latency coupled with the relatively poor vertical resolution capability of the current NWP models conspire to make 'surpise' output turnarounds likely in even the statistically reliable modeling timeframe.

In the meantime, look to the other indicators for guidance. Extended range ensemble means, frictional & mountain torques, ENSO, GWO phasing etc.

Patience young Padawan's. Winter will return.

ffO.

[Severe Siberian icy blast]

I have no idea what happened then , but as you can see my thoughts are there !

[UV-RAY]

Who is looking for a Greeny high all the time.Not me,we have just had a two week cold spell without one.

If ECM is to be believed there is plenty to please never mind your straw clutching and clock ticking stuff.. http://www.meteociel...900/ECH1-96.GIF

http://www.meteociel...1-168.GIF?29-12 N/Westerly in yby http://www.meteociel...0-168.GIF?29-12 nice 850s

And this to finish BY day 10 http://www.meteociel...1-240.GIF?29-12

There is more to clutch at in ONE run than in many previos winters.

GFS ensembles look fine too and people would have gladly accepted these through the years http://www.wetterzen...chester_ens.png

Yes a lot of areas did very well out of that cold spell, but what we are looking at now are brief flirtations with cold not the deep cold synoptics touted by some on here. We would have to see an amazing turnaround in the model output within the next week if it's sustained cold we want, that looks highly unlikely at this stage, so the best we can hope for is RPM between the warm sectors.

[chionomaniac]

A few things need to be said .

The Azores high is setting up shop to the west of uk, not northwest, and certainly NOT towards greenlands, the charts have northerly topplers written all over them.

The Canadian vortex is too much of a feature , even in deep fi and no heights will build toward Greenland with this the case.

We was told with a certainty the downwelling from the SSW would have its impact on or just after 28ths jan, this has not happened.

The SSW had an initial impact on us With a rapid response . If it wasn't for that we would all be going mad.

The topplers now coming into the forecasts have absolutely nothing to do with the SSW.

Either the models are about to a massive flip and recognise this downwelling and show signs of northerly blocking or . . .

Is not going to happen, and looking for cold for the 10th feb is nearly half way through the month and 13days late so can what happens then be down to the downwelling or just a typical February ?

Personly I think if we don't see a model flip in the next 4 days , and by a flip I mean obvious signs of a SSW affect , then certain ones including myself need to take a step back with the strat and recognise its a science in its VERY EARLY stages and accept its pattern of behaviour can be sporadic and unreliable .

I say this because GP has been so certain with his predictions but yet this year hasn't gone to plan as of yet. If it wasn't for the rapid response then this winter would have been one of the worst in living memory .

Not digging at anyone, just saying it as I see it.

Shaun.

Just a couple of points of order here Shaun.

Firstly for me, (with the knowledge that SSW's are hit and miss affairs) the SSW has more than delivered for me this winter - even if we don't get anything more from further downwelling. The whole tropospheric pattern is still being influenced to a more or less extent by the SSW (as well as other telecomnnections) - so to say that the topplers have nothing to do with the SSW is incorrect. it may be that some just don't like their influence on our shores.

You are correct in your assertion that we still have a lot to learn about stratospheric tropospheric interactions and feedback - but progress is being made. With the upper strat PV slowly reforming we will see some changes with, I suspect, the waning of the troublesome Canadian segment. There are still no signs that we will see anything other than topplers in the first week of Feb - but to me this pattern is still being dictated by events north of Greenland and towards the Pacific sector.

[AWD]

If the ECM verified then we would be looking at a wet winter storm on Friday. There is a hell of a lot of rain here;

As well as gale force winds;

And as the low digs S/SE it draws down colder 850hpa temperatures increasing the risk of back edge snowfall;

Be interesting to see how/if this develops further.

[Backtrack]

Something to note:

Yesterday I was watching BBC Points West with Ian F. He mentions that a low is likely to develop around the channel area, next week to bring an incursion of colder air.

Can't remember the exact details but this is what he said. He also said the charts did not reflect this right now.

[SMU]

I think that we will see a return to very mild SW'lies to dominate February and that winter 2012/3 has been ok but is over now. I hope you enjoyed.

Might as well say it, that's all I'm reading at the moment.

BFTP

LOLOL- & how many berated me for mentioning the fat lad warming up.

Its not over, however with a fear of repeating the same thing - a circular azores high just west of ireland is a woeful pattern to try & get cold into the UK, at best it elongates to the south of greenland & the 18z last night would be as good a pattern you can get- with heavy snow showers in the North & north west- However you are always watching the clock in that scenario waiting for the atlantic to flatten it all out...-

The models have eased away from that scenario this morning- which was painted by the ECM 12z & the 18z GFS, they have instead just tweaked the amplitude to a lower wave & moved the inflection point of the jet further east, so essentially 'most' not all of the cold is steered towards the continent.

The ECM ensembles for Debilt paint a perfect picture of peak cold day 11 with the lowest mean at that point, then recovering.

If you want cold that lasts then for anywhere other that Northern Scotland & extreme Northern hills its not good, at the height of cold for 1 day it will be good for the NW & places like the cheshire gap streamers-

Instead of cold we may want to concern ourselves with the 977 Low thats over Kent on Saturday.

http://www.meteociel.fr/modeles/ecmwf/runs/2013012900/ECF1-96.GIF?29-12

Storm force winds & flooding likely.

S