Model Output Discussion 4th Dec.2013-12z onwards.

[mountain shadow]

The GEM is a very poor performer in winter, I've said when it has been showing zonality against the others and I will say it again now that it is showing easterlies. We can discount it. Agreed IranThis Sceuro High will not do us any favours. At least a short return to zonality might allow the opportunity for some favourable amplication as the PV remains stretched.The GFS is very anti-cyclonic throughout but I feel it is wrong with the height extension Westward at around day 9 and the ECM is more likely with the gradual Atlantic incursion leading to more conventional zonality from around Dec 16.

[Gibby]

Hi everyone. Here is the report on the midnight outputs from GFS, UKMO, GEM, NAVGEM and ECM for today Thursday December 5th 2013.

 

All models show a deep depression running ESE across the Northern North Sea and down into Central Europe tonight and tomorrow. A spell of windy weather is shown for all with severe gale or even storm force gusts of wind in the North later today for a time. A cold front also moves South with a band of rain reaching Southern England this evening followed by clearer and cold conditions with snow showers across the North by tonight, transferring to NE Britain while most other areas see decreasing winds and clear skies along with a frost. High pressure then moves in close to the South tomorrow as a warm front moves around the top of the High across Britain late tomorrow and on Saturday returning the UK to milder and cloudy weather but dry conditions once early rain and sleet clears the NE. This then heralds a prolonged period of stagnant conditions across the UK.

 

GFS shows Westerly winds to start next week gradually backing Southerly with increasingly mild conditions expected especially over the North and West with a little rain and drizzle possible over hills and coasts at times. In the South and East though technically similar conditions overhead it may well be a little less mild here with less breeze and slightly drier air allowing the risk of some mist and frost patches if skies clear to any degree overnight. Through the remainder of the run High pressure continues to have complete control over our weather with dry and cloudy conditions likely to continue with temperatures close to average under an inversion most of the time.

 

UKMO closes it's run next Wednesday with High pressure stretching from Southern Britain to the Baltic Sea. Much of England and Wales would be largely calm and cloudy and possibly rather cold feeling. Should the general cloud cover break from the SE then frost and fog could develop making it very cold locally. Scotland and Northern Ireland would stay rather cloudy and certainly milder with a little hill fog and drizzle near Western coasts.

 

GEM today continues to show a very wintry situation developing as the latter part of next week develops. High pressure which stretches from the UK to the Baltic midweek intensifies North to Scandinavia as a surge of cold Russian air moves West on the Southern flank of the High at the same time as a deep Western Atlantic Low pumps troughs down towards Iberia and Biscay which intensifies a strong and bitter East flow with potential for snowfall across Southern Britain by the second weekend.

 

NAVGEM maintains High pressure on a more Southerly latitude continuing the static and rather cloudy Southerly drift over the UK later next week. It will feel a little colder in the SE with the flow from a Continental land source but chill rather than cold would be the feel while the NW stays quite mild.

 

ECM today too holds High pressure more towards the SE of the UK rather than East with the UK well and truly on the warm side of this feature with gentle SW winds and mostly cloudy skies the likely weather pattern. Some drier and colder air could skirt the far SE at times making it less mild here and later in the run Low pressure troughs would be closing in on NW Britain with increasing winds and a greater threat of rain likely here by next weekend.

 

The GFS Ensembles show a markedly dry period coming up for December with little if any noteworthy rain events shown by hardly any member through the period. In addition a sustained spell of mild uppers cover the UK in a Southerly drift from Southern Europe or the Southern part of the North Atlantic. There is a slow trend towards more average conditions late in the run but this looks due to natural variability in members's predictions at that range rather than a particular trend.

 

The Jet Stream shows the flow diving SE down the North Sea around the deep Atlantic storm to the NE today. Thereafter it surges NE back towards Iceland and Northern waters where it remain blowing strongly for almost the entire period from the SW.

 

In Summary there is still little excitement in the weather patterns over the UK for the next couple of weeks. With the Jet stream blowing very strongly East and NE well to the NW of the UK for the foreseeable there is little manouevreability for High pressure over Europe to edge North next week to Scandinavia to change the pattern to something more wintry. GEM manages to do it though for the second operational run in a row but looks very isolated among a pack of much milder benign options which all show a light Southerly flow with warm uppers wafting up across the UK. As it's winter inversions are likely to form over the UK with a lot of cloud trapping some colder air at times near the surface and this is likely to occur next week across the South and East at times while the North and NE have the chance to achieve some very mild value temperatures at times in the weak SW flow. It is currently hard to see where and when we will break out of this pattern with the clock ticking to what would be a very dry and benign December if the charts verify up to later December as is shown this morning but we must always remember a week or two is a long time in meteorological terms and things can change fairly quickly and probably will.

[winterof79]

Ah well, at least we have these charts, normally at T+240 hours range but not this time...

 

No doubt some will find a way to see no snow for the north from this

http://expert-images.weatheronline.co.uk/daten/proficharts/en/nae/2013/12/05/basis00/ukuk/prty/13120618_0500.gif

Edited December 5, 2013 by winterof79

[R.P. McMurphy]

GFS shows Westerly winds to start next week gradually backing Southerly with increasingly mild conditions expected especially over the North and West with a little rain and drizzle possible over hills and coasts at times. In the South and East though technically similar conditions overhead it may well be a little less mild here with less breeze and slightly drier air allowing the risk of some mist and frost patches if skies clear to any degree overnight. Through the remainder of the run High pressure continues to have complete control over our weather with dry and cloudy conditions likely to continue with temperatures close to average under an inversion most of the time.

 

The GFS Ensembles show a markedly dry period coming up for December with little if any noteworthy rain events shown by hardly any member through the period. In addition a sustained spell of mild uppers cover the UK in a Southerly drift from Southern Europe or the Southern part of the North Atlantic. There is a slow trend towards more average conditions late in the run but this looks due to natural variability in members's predictions at that range rather than a particular trend.

 

 

 

Hi Gibby,

 

It's looking a little dry for Southern Area's but not so much up North, especially the west.

 

[Weathizard]

Why are people saying the 'trend' to zonality? I don't see it? In fact just quickly scanning the models this morning I see nothing zonal or any more of a trend to zonal than HLB on any model?

The models this morning look extremely benign to me, with the ensembles for lots of the England(Not far north/Scotland) giving no rain, or very low rain amounts for all of the next 15 days. Mid-latitude blocking looks the ongoing theme, as it has been for the past 2 weeks, nothing much to get excited about currently.

Edited December 5, 2013 by Weathizard

[snowking]

The GEM is a very poor performer in winter, I've said when it has been showing zonality against the others and I will say it again now that it is showing easterlies. We can discount it.

 

The GFS is very anti-cyclonic throughout but I feel it is wrong with the height extension Westward at around day 9 and the ECM is more likely with the gradual Atlantic incursion leading to more conventional zonality from around Dec 16.

Not according to the stats at present Ian:

 

 

Level pegging with the UKMO at day 5, still comfortably ahead of the GFS at day 6:

 

That's its best verification statistics for some time and I believe we are now officially in winter. When you look at the 12z stats the beloved GFS sits even behind the JMA in 5th place.

 

In terms of the suggestion of 'conventional zonality', there is very little to suggest this from either the GEFS or the ECMWF EPS this morning.

 

GEFS even by the 18th:

 

 

Still with a very strong signal for MLB.

 

Awaiting the extended ECMWF ensembles but out to day 10:

 

 

Still a very strong signal for MLB.

 

So I am not entirely sure how any of your post is accurate? Perhaps in future it may help to provide a little evidence to back up your claims. This will also help any newer members who are trying to learn rather than misleading them.

 

Of course at 10 days away we cannot take anything for granted and indeed the final result may well be something closer to zonality, but off current face value evidence there is nothing to suggest such an outcome.

 

SK

Edited December 5, 2013 by snowking

[Weather Boy]

Not according to the stats at present Ian:

 

 

Level pegging with the UKMO at day 5, still comfortably ahead of the GFS at day 6:

 

That's its best verification statistics for some time and I believe we are now officially in winter. When you look at the 12z stats the beloved GFS sits even behind the JMA in 5th place.

 

 

SK - which is the GEM line on that graph?  I can see the 'big three' and then some acronyms that I am unfamilar with (CMC and FNO) but not GEM.

 

Not saying that Ian is right -and he has offered no evidence in support- but with official winter being less than 5 days old, it's not much evidence to form a judgment of models' performance "in winter" at this point in time, whether good or bad.

[draztik]

WB, the GEM model is operated by the Canadian Meteorological Centre (CMC) on the verification stats.

[shedhead]

The current outputs suggest the UK may become the new Atacama,  with the very dry looking outlook still being the main signal.  As Nick S alluded to the orientation of the high could make a big difference to temps across our relatively small island next week, but for now I see it as being on the mild side for most (and locally very mild), with areas SE of a line from Portland to the Humber being closer to average.

Edited December 5, 2013 by shedhead

[Gavin Hannah]

Might I offer this idea, if the GFS and ECM can not decide how they want to play over the next few weeks, might we champion the GEM and all it's wintry glory as the model leading the way..?

 

 

Just going to add that I'm surprised my internet is still up lol... it's pure blawin' a gale here!

Edited December 5, 2013 by IBTHToThoseShortwaves

[snowking]

SK - which is the GEM line on that graph?  I can see the 'big three' and then some acronyms that I am unfamilar with (CMC and FNO) but not GEM.

 

Not saying that Ian is right -and he has offered no evidence in support- but with official winter being less than 5 days old, it's not much evidence to form a judgment of models' performance "in winter" at this point in time, whether good or bad.

No I completely agree, I am being a little pedantic in all honesty but I am growing tired of seeing constant calls for 'a return to zonality' with no evidence to back things up. I am always open to any idea if somebody can provide a reasoned and evidence-based argument, but without it becomes nothing more than a Madden style guess-cast. It may well be that he has some evidence to back these ideas but the only evidence I have seen from Ian in the past is some vague references to the 'American guys'.

 

Anyway - the GEM is the light green line, the CMC.

 

The best way to calculate the performance from these is to use the figures at the bottom left - these provide averaged verification stats over a period of 30-31 days.

 

Kind Regards

SK

[Uncle_Barty]

To me, it seems the whole normal pattern has been shifted north. True, it's not raging zonality, but there is a fair element of zonality - but it is well north, leaving us in this largely benign pattern. (fine by me - lower heating bills, no travel and sporting disruption ! Hope this lasts till March...)

 

Perhaps this is a case where a disrupted vortex has not worked in "coldies' " favour, but has allowed the pattern to shift north. I don't think this is a "standard Bartlett" scenario as we don't have a strong-ish vortex allied to extensive lower-mid latitude blocking in a belt not far south of us. This isn't a 1988/89 yet.

 

As someone else said a few posts ago, this can change fairly quickly given a shift in the long-wave pattern, so all is not lost for winter-lovers.

[Gavin Hannah]

GEM t.240

 

 

http://meteocentre.com/models/explorateur.php?mod=gemglb&run=00&stn=TT850&hh=240&map=eur&stn2=TT850&run2=12&mod2=gemglb&hh2=240&comp=1&fixhh=1〈=en

 

 

GEM sticking to it's idea of HP to our north/north-east.  

 

Now in the 1000 club!!

Edited December 5, 2013 by IBTHToThoseShortwaves

[TSNWK]

Morning Folks, any views on this Mornings ECM ensembles please, basically are there GEM options for us....

[forecaster]

No I completely agree, I am being a little pedantic in all honesty but I am growing tired of seeing constant calls for 'a return to zonality' with no evidence to back things up.

 

Part of the problem is that there's no true definition for "zonality". It doesn't strictly mean anything, therefore can mean all things to all people, hence we end up in discussions where a member says "return to zonality" then the endless "I don't see anything like zonality, in fact just the opposite!" follow ups. The term "zonal" itself - with respect to wind direction - could mean winds with a predominant westerly or easterly component. But that's obviously not what's meant by "zonality" since no one calls an easterly flow "zonal" even though it really is. So does "zonality" mean frequent depressions tracking across the country from the Atlantic? In terms of the global circulation model, that's just called "westerlies". 

[Gavin Hannah]

I see the GFS 06 is rolling out. Will be interesting to see where this run goes. Will it stubbornly stick to whats been shown in the last few runs, or can it tred to GEM??

[R.P. McMurphy]

The current outputs suggest the UK may become the new Atacama,  with the very dry looking outlook still being the main signal.  As Nick S alluded to the orientation of the high could make a big difference to temps across our relatively small island next week, but for now I see it as being on the mild side for most (and locally very mild), with areas SE of a line from Portland to the Humber being closer to average.

 

This is misleading... The North of England isn't predicted to be bone dry. Just southern areas south of Birmingham with a few dry days.

 

I count 4 dry days for Southern Area's below :-)

 

Atacama it is not.

 

[UV-RAY]

This is misleading... The North of England isn't predicted to be bone dry. Just southern areas south of Birmingham with a few dry days.

 

I count 4 dry days for Southern Area's below :-)

 

Atacama it is not.

 

 

 

Back to the model output or shall I say lack of interesting things to talk about. I still can't see heights becoming established over Scandinavia within the next 10 days at least, the weather really does look very benign for the foreseeable but one thing it doesn't look is mild except perhaps NW Scotland and Ireland, average at best and below average for the SE.

Edited December 5, 2013 by phil nw.
Removed reported snipe.

[Frosty.]

wow this is amazing, might get a few flakes of snow after all

[karlos1983]

That's a pretty impressive cold pool heading into the Bay of Biscay at +240 by the GEM, lol, bet Nick S would be happy to BANK that!!

 

 

Looking cold in Blighty to, especially to the south!

[EML Network]

Well regradless of the zonal question, All I can see from start to end of the last few days runs is more of the same boring nothingness that we have experienced over the past week or so.

 

The UK either directly under High Pressure, or High Pressure sitting to our South or  South East , with everything either running over the top or stalling out to the west an interesting 48 hours coming up but there after it's anything but interesting.

 

Since mid June the weather in the UK really has been non descript and really boring in terms of anything extreme....global warming ??? more like global BORING.

[Frosty.]

Glenn you should know by now what effects  Southern England effects all of us.

 

Back to the model output or shall I say lack of interesting things to talk about. I still can't see heights becoming established over Scandinavia within the next 10 days at least, the weather really does look very benign for the foreseeable but one thing it doesn't look is mild except perhaps NW Scotland and Ireland, average at best and below average for the SE.

Exactly as the met office update yesterday. Take my hat off to those guys

Edited December 5, 2013 by Frosty.

[karlos1983]

Well regradless of the zonal question, All I can see from start to end of the last few days runs is more of the same boring nothingness that we have experienced over the past week or so.

 

The UK either directly under High Pressure, or High Pressure sitting to our South or  South East , with everything either running over the top or stalling out to the west an interesting 48 hours coming up but there after it's anything but interesting.

 

Since mid June the weather in the UK really has been non descript and really boring in terms of anything extreme....global warming ??? more like global BORING.

 

Probably disagree with that last sentence, October was pretty interesting I recall, especially in our part of the world. Also had some decent Electrical storms in the summer

[Gavin Hannah]

Anyone up for starting a GEM only thread for us coldies?? 

[TSNWK]

06:00 GFS not having the GEM option.