Model Discussion Thread - 15th Jan

[OldMetMan]

It looks to me that the 18Z GFS is even weirder than the 12Z ECM. Beyond about 144H it seems to lose the plot and looks to be sending yet another powerful US jet in our direction beyond that time - with its common theme of zonality returning. And what happened to the LPs heading SE from S Greenland in the medium term?

Need to see the rest of the run yet though to see how it resolves.

Hmm, as I thought, the GFS just doesn't know what to do.

Just a thought, one possible scenario beyond 120H or thereabouts is for the HP to build NE and for the long wave pattern to sharpen abruptly - upper trough building SE from Canada, upper ridge building N towards Iceland and the Norwegian Sea, upper trough extending S and SW from Europe. The net effect would clearly be some sort of easterly, which sort dependent on where the centre of HP centres itself.

See what the UKMet says later.

Edited January 15, 2012 by OldMetMan

[kold weather]

Wow what an awful GFS run, it was obvious it was going to be a bad run as soon as it sent pretty much nothing SE into Europe around 120hrs and the PV fragment shifted NE rather then SE.

Still thats a shocker even by this witners standards, one of the worst runs for a long time from any model.

I bet its an outlier, it really shoots the AO back very positive again, total outlier compared to recent runs and trends...

[TEITS]

Lets be honest here with the model output over the last few days you could say anything from a mild SW,ly, cold E,ly, cold N,ly, cool NW,lys are all options from +144 onwards. Whats ironic is you could use the models to back all these scenarios up. Just take a look at the 12Z ECM, 18Z GFS, 18Z NOGAPS as a clear illustration.

My point is these models don't have a clue what will happen after +144 and neither do I. This in my opinion is when posts from GP become especially helpful.

[nick sussex]

Oh dear!

I'm sure the GFS is doing this to just keep the drama going so there'll be a good turn out in the morning!

Not much to say really but can we just put this model out of its misery! Theres solid support for the Azores ridge displacing west, a bit like this example from the NOGAPS which used to be called the no clue model but which has now been promoted above the GFS as thats obviously even more clueless.

http://www.meteociel.fr/modeles/nogapse_cartes.php?&ech=144&mode=0&carte=1

On to tomorrow where the next installment of this long winded saga continues.

[mountain shadow]

Well, positives or not, today's models show a milder spell next week followed by a very brief cold snap followed by milder again. Their are hints of something colder however despite the PV vacating Greenland it does not do so to benefit the British Isles.

Unless we get proper ridging into Greenland, and I mean the oranges and yellows on the 500hpa then I feel the northern arm of the jet will continue to eject too much energy to allow any ridge to get far enough north before linking with the Russian high.

[Bristawl Si]

GFS continues it's love affair with he HP to the south of the UK.

But plenty of positives this evening if one is looking for cold..and maybe snow.

• IMO The tone of GP's earlier post had no hint of doubt in it - in fact it seemed to me as if it was saying "Happy with the way things are proceeding in line with the LRF" i.e. we're on track - (If i've incorrectly interpreted then apologies).
  
• ECM/NOGAPS/UKMO - all have shown a favourable scenario leading up to or from next weekend
  
• Twitter chat with the weather guys is still talking about the ECM solution
  
• GFS does seem to be out on its own at the mo
  

Weighing all this up IMO says we're in for a change from the weekend

[snowlover2009]

I'm really excited by the GFS, potential is huge.

I think those focusing on highs building over Greenland will be greatly disappointed as the PV is just too strong. Strat warming isn't displacing the PV, instead creating huge block over Russia.

Look at the cold air building over Norway with heights increasing

Look medium term, not long term. Yes the high isn't strong enough post T150 but the more it builds on each run the less likely it is to flatten.

That chart has so much potential and it will change. Look at the big scandi high that was being projected for the end of the week, last week. Ok so there is still heights there, but the high being projected last week, was a classic scandi and it kind of disappeared off the gfs, or collapsed. Nothing stopping the chart above, to move north and makes things interesting for us.

[PolarWarsaw]

Anyone staying the distance tonight for the 0z? Lets hope whatever it shows is something better than the 18z. Could see at t96 that things werent going to shape up like the 12z. Last one from me tonight. I was leaning towards cold and am still slightly in favour of a cold evolution however, the 18z stinks sadly.

[TEITS]

Well, positives or not, today's models show a milder spell next week followed by a very brief cold snap followed by milder again. T

Have to be honest im not sure thats a fair assesment of the models this evening. The 18Z GFS, JMA suggest turning milder but the NOGAPS, ECM, UKMO certainly don't. The ECM mean has dropped by a couple of C aswell.

No assumptions should be made at the moment because come tomorrow morning I have no idea if the ECM will be showing a cold E,ly or a mild W,ly and thats between +144 to +192 lol.

Funny only a few years ago I would be shouting for an E,ly. Funny how i've changed over the years!

Edited January 15, 2012 by THE EYE IN THE SKY

[snowblues]

What i dont under stand from a learner in model watching is that from frame 144 there is low pressure in the med and a great huge area of high pressure in russia , how does that atlantic high push its way through? it does not seem right !any takers?

[TEITS]

GEFS control is much better.

http://modeles.meteo...-0-1-114.png?12

Looks to me as though the 18Z GFS is wrong very early on.

NE,lys at +132.

Edited January 15, 2012 by THE EYE IN THE SKY

[john mac]

Anyone staying the distance tonight for the 0z? Lets hope whatever it shows is something better than the 18z. Could see at t96 that things werent going to shape up like the 12z. Last one from me tonight. I was leaning towards cold and am still slightly in favour of a cold evolution however, the 18z stinks sadly.

Noy going to bother after the 18z. lol. It will be interesting to see if the extra data they are collecting will give the the models a better handle on the situation in the morning. Any news on the fax charts?

[Jason M]

GEFS control is much better.

http://modeles.meteo...-0-1-114.png?12

Looks to me as though the 18Z GFS is wrong very early on.

NE,lys at +132.

http://modeles.meteo...-0-1-132.png?18

Ensembles on their way out but they look very good indeed to my eyes up to 144. The 132 control has a lot of support. The opp is the mother of all outliers!!!! and wrong IMO.

Edited January 15, 2012 by Jason M

[kold weather]

Control run looks much more like it. Nice cold flow coming down and a ENE/NE airflow by 144hrs, amazing contrast to the GFS operational run!

[lorenzo]

Well , another day and every solution you want on the table!

NOGAPS follows seemingly UKMO with NNE ridging and similar modelling of the lobe of cold over Scandi as it drops SE.

ECM not far behind at this stage.

GFS determined not to follow suit and instead compared to the other 3 at this time frame is busy with another mess of lows and super-charging the Russian High.

GFS 00z to play catch up in the morning? Ironic that it's playing catch up for in some areas it is being too fast..

[snowlover2009]

The ensembles are looking very good up to 144 hours, we are seeing heights pushing up to greenland, linking with heights over europe and troughs to the south east. This is very good. Just looked at the OP and nothing like any of the ensembles or the control.

[kold weather]

Ensembles really are light years better for cold, indeed there is some eye raising runs being produced, No.14 for example is very good!

I suspect the 18z is an outlier both in terms of temps and synoptic evolution, expect changes on the 00z run...

[TEITS]

Control run looks much more like it. Nice cold flow coming down and a ENE/NE airflow by 144hrs, amazing contrast to the GFS operational run!

Yep one for Steve M.

The mean is even more impressive considering it is the mean.

The 18Z GEFS ensembles have flipped towards what the ECM was showing a few days ago i.e NE,E,lys.

[Catacol]

Not much comment on GP's earlier thoughts? If he thinks the Azores High is going to be dragged westwards around day 10 - 15 that's good enough for me. Angular momentum low so overall tendency for the pattern to back west and the Russian High exert an ever greater influence. Could we have a mega block develop with the azores high sucked to Iceland by that growing Russian High? I think it's on...

I've seen enough in the models in the last week, plus that comment from Stewart, to go dust off my sled and find the gloves from last year. This is the week of transition with the vortex wobbling and breaking up. Next week blocking to the north and low pressure to the south. Looks about as nailed on as the northerly of Dec 2010 to me - just a bit less certain on timing.

Edited January 15, 2012 by Catacol_Highlander

[Zakos]

GFS somehow manages to embaress itself further on the 18Z.

It goes against almost full model consensus, being far to bullish with the Azores high

It has handled the mid jan pattern absolutely appallingly IMO. ECM did sway from the cold spell earlier for a couple runs, but it had picked up on it a long time ago and remained fairly consistent with it throughout.

As I write this, I see the GFS op has lost support even from its own ensembles. truly embarrassing. I used to rate the Gfs over all models, but it has been pathetic lately IMO.

[nick sussex]

Yep one for Steve M.

http://modeles.meteo...-0-1-156.png?18

The mean is even more impressive considering it is the mean.

http://modeles.meteo...21-1-144.png?18

The 18Z GEFS ensembles have flipped towards what the ECM was showing a few days ago i.e NE,E,lys.

It really is a mystery! Thats a big swing in the GEFS ensembles today, shame the GFS didn't pull one of those out to deliver this evening rather than that tosh we were all subjected to!

[J10]

FAX 120H is out

Not surprisingly it seems to have gone with the UKMO model, NW winds with sub 528dam most of the UK.

[Frosty.]

I'm actually not concerend about the rogue Gfs 18z run as it looks completely out of sync with the 12z output today. Reading GP's comments about the azores high likely to be pulled westwards is great news and all the other more knowledgeable posters who are taking lots of positives out of the output is reassuring. Only wednesday will be mild in the upcoming week but then trending colder from the northwest with increasing risk of wintry showers, i'm more optimistic about upgrades to colder weather in the medium/longer range than I was this morning.

[kold weather]

Indeed Eye, its quite surprising considering the GFS ensemble support for anything cold has been a little half-hearted. This is the first time its really gone and given nearly full support. Even some of the lesser runs are still better then the 18z op run.

some amazing solutions even by 120hrs, very big differences out there tonught again even at that short timeframe!

Honestly...best ensembles this winter...by some way!!

[Zakos]

well If the 18z ensembles are anything to go by, the op is going to be a huge outlier.

And today's 18z compared to tommorow 00z is likely to be the largest backtrack from the GFS I have ever seen at such a short time range!