Model Output Discussion - 1st - 7th January

[SMU]

well no stella run but better-

The GFS is handling the system over the central states at 130 totally different to the ECM- the ECM holds it as one & moves it up to the canadian maritimes, where as the GFS splits it & ejects a shortwave east off the coast - ensuring that no ridging can get going North-

Pity because the AO index & 180 will be the lowest reading of the winter-

S

[Dave Kightley]

well no stella run but better-

The GFS is handling the system over the central states at 130 totally different to the ECM- the ECM holds it as one & moves it up to the canadian maritimes, where as the GFS splits it & ejects a shortwave east off the coast - ensuring that no ridging can get going North-

Pity because the AO index & 180 will be the lowest reading of the winter-

S

nice end to the run though steve. shame high pressure builds back in right at the end? Edited January 6, 2012 by Dave kightley

[SnowObsessor90]

End of FI=

[Brum Watcher]

another failed GFS run in fi, but sure changes are due somewhere down the line..time to sit out the yellows for now!!

[SMU]

well its all irrelevent to the Shortwave is resolved at 130>168 & its trajectory-

S

[nick sussex]

that trough has gone on the gfs 18z that nick was talking about earlier on. like on the ukmo... which has made the difference j.s

It's the shortwave that the ECM and GFS developed, its gone here but the GFS decides to just be a pain and not follow the script after that.

In the higher resolution output the GFS 18hrs is better than the earlier 12hrs but in the lower resolution goes back to the PV love in near Greenland. Watching this model output at the moment seems like one long trudge through a peat bog!

Painfully slow, we can see salvation ahead but it's just out of reach. The important synoptics are now coming into the 168hrs timeframe so it shouldn't be too much longer before we know what trend will be the accurate one.

Re Steves post he's talking about a different shortwave, why is nothing simple with getting colder weather into the UK!

Edited January 6, 2012 by nick sussex

[phil nw.]

well no stella run but better-

The GFS is handling the system over the central states at 130 totally different to the ECM- the ECM holds it as one & moves it up to the canadian maritimes, where as the GFS splits it & ejects a shortwave east off the coast - ensuring that no ridging can get going North-

Pity because the AO index & 180 will be the lowest reading of the winter-

S

Unfortuantely time after time all the vortex breaking is modelled the wrong side of the pole Steve.AO going neg.and us being ruled by Azores high pressure and a flat trans atlantic pattern missing out on the cold.

http://176.31.229.228/modeles/gfs/runs/gfsnh-2012010618-0-288.png?18

[lorenzo]

18z GFS wants to please its verification stats diluting the cut off...?? It fairly goes off on one at 240.

[phil nw.]

TBH even at T192 you could see this run was only going one way,

The evolution thereafter for the UK simply reflected the upstream flat vortex over Canada with the energy ejecting eastwards into the Atlantic.

Edited January 6, 2012 by phil n.warks.

[SP1986]

I would agree, the 18z FI period throws up a strange scenario, certainly not in the Meteorological textbook of common pattern outcomes. On that alone I'd be sceptical of such a run.. and whilst I know these comments won't be met with enthusiasm by the cold enthusiast, it's FI is admittedly somewhat different from those that go before it, and therefore even more unlikely anyhow.

Still there is some decent attempt to create a ridge-block over eastern Canada just after 130 hours, so the building blocks for a pattern change, if there is to be one are settling into the medium range now.

In the mean time, high pressure dominated up until then with relatively mild weather, perhaps mild air getting advected into the high pressure. However the latest model runs beginning to suggest a fairly calm and therefore frosty few days around Tuesday-Thursday, with a slack situation. Could be pretty foggy too looking at the synoptics, but no ice days.

[summer blizzard]

I retain my thoughts for the previous few days which is that with AO going negative and ensembles still indicating a change from the 15th, a pattern shift will occur although we may need the second blast to really put us in the freezer.

The day 9 ECWMF12z chart is without a doubt perfection in terms of the Greenland block which would form within a few days and the trough dropping into Europe.

[Dave Kightley]

putting this aside fl seems to be around 130z as steve said. alot of changes i gather until the models agree on the pattern ahead. it must be hard to deal with a whole NH pattern changing for the models

[MP-R]

Well not much change on the 18Z regarding the state of the PV but one thing that does appear on the GFS is a trough over Iberia towards the end of the run. Without that, the high to the south of us would just sink back into Europe but instead it's edged between that and low pressure to the north. If only it can keep it's strength then maybe a more favourable orientation of the high over us will give us at least something of a continental flow.

On the other hand, it could disappear on the next run. Other than that, a pretty mild run with only average at best. A rather uneventful, unseasonal week to come next week.

[SP1986]

I retain my thoughts for the previous few days which is that with AO going negative and ensembles still indicating a change from the 15th, a pattern shift will occur although we may need the second blast to really put us in the freezer.

The day 9 ECWMF12z chart is without a doubt perfection in terms of the Greenland block which would form within a few days and the trough dropping into Europe.

Looking at the ECM charts, and the situation over Greenland, there probably wouldn't be enough momentum on the warm air advection to create the differences in spatial atmospheric temperature to forge the high. It may, like you suggest primarily, need another go, based on those ECM charts tonight.

The Greenland high doesn't quite set up, as the vortex just about restricts it, and without that strong anchor over the heart of Greenland, it would probably topple, this time.

[snowlover2009]

GOOD GRIEF!!!!

http://176.31.229.228/modeles/gens/run/gens-16-1-264.png?18

[Brum Watcher]

GOOD GRIEF!!!!

http://176.31.229.228/modeles/gens/run/gens-16-1-264.png?18

well not many others supporting...

[snowlover2009]

well not many others supporting...

I'm just saying,

Got to say, as a storm lover and cold lover, there is plenty of options open on the models today. Just gone through all 20 gfs ensembles, you either get cold zonality and storm systems, lows digging south or some decent cold spells. No sign of anything mild from what I can see or mild weather pumping up from the south after 192, but FI is much closer to the timeframe. But a long way to go yet, but it looks good either way IMO.

Edited January 6, 2012 by snowlover2009

[SP1986]

GOOD GRIEF!!!!

http://176.31.229.22...16-1-264.png?18

Pretty impressive chart right there, the PV over the UK.. impressive.

I'd love to see a chart like that verify.. whilst it wouldn't necessarily bring wintry weather, it would bring with it major instability and some wild weather.

[snowlover2009]

Pretty impressive chart right there, the PV over the UK.. impressive.

I'd love to see a chart like that verify.. whilst it wouldn't necessarily bring wintry weather, it would bring with it major instability and some wild weather.

I would, but that would be an absolute insane winter storm. Don't think i have ever seen the PV so strong over the UK. Definite trend on the 18z to something much more interesting for the end of next week. The 18z ensembles remind me of early december, but much colder and have more potential.

http://www.wetterzentrale.de/pics/MT8_Aberdeen_ens.png

Definite cold trend! the start of the second half of the month could be interesting period.

I know I have already said it, but the trend is either cold stormy zonality or the potential for a proper cold snap/spell of winter, from what I can see next weekend onwards.

[Bobby]

I would, but that would be an absolute insane winter storm. Don't think i have ever seen the PV so strong over the UK. Definite trend on the 18z to something much more interesting for the end of next week. The 18z ensembles remind me of early december, but much colder and have more potential.

http://www.wetterzen...berdeen_ens.png

Definite cold trend! the start of the second half of the month could be interesting period.

Yes it looks like an interesting period coming up one way or the other. Some of the charts are looking pretty wild and some better hints at a cold spell too.

[SP1986]

The Aberdeen ensembles look more cold orientated than the Manchester and London ensembles, and there's a fair bit of ridging and troughing of the ensembles members, suggesting frequent toppler situations with frequent northerly incursions, there are however a small amounts members showing sustained cold as well - anybody's guess at the moment..

[snowlover2009]

Yes it looks like an interesting period coming up one way or the other. Some of the charts are looking pretty wild and some better hints at a cold spell too.

Yep, it looks like one or the other and if you prefer either, then its great. TBH I think, the models are slowly going to latch onto a sneaky cold spell very soon.

[La Bise]

That PV lobe chart over the UK is insane, 935mb core...!!!! Surely most of the country would be flattened if this happend?

[SP1986]

That PV lobe chart over the UK is insane, 935mb core...!!!! Surely most of the country would be flattened if this happend?

With something like that thundery showers, 'mini'- tornadoes, hailstorms looking at the potential temperature of the upper atmosphere. We can but dream, I suppose.

[feb1991blizzard]

That PV lobe chart over the UK is insane, 935mb core...!!!! Surely most of the country would be flattened if this happend?

Pity it will track a few hundred miles further North of where its progged rather than a few hundred miles further south with a massive ridge up its ass.