Model output discussion - Post SSW - Will it turn cold?

[SLEETY]

3 minutes ago, Summer Sun said:

It is fair to say ECM looks a little bit isolated at t168 this morning

UKMO looks unsettled and not overly cold

Not really every ukmo charts never seems to verify at That range ,and the met are dismissing their own model so it’s in the bin really

 

[stotm]

3 minutes ago, SLEETY said:

Last two ecm runs going for cold last two meto runs going less cold,something’s got to give in next run surely

im not bothering with gfs its just junk how it just flips and flops every 6 hours

Very true it’s almost random, that’s why it has 4 goes a day ?

[Frosty.]

So...what we have is the Ecm 12z last night setting the stage for a mega cold shot from russia and excellent continuity with the 00z following through on that potential!..and the mean improving too..I'm happy!

[SLEETY]

Yes it’s happening frosty,the met office super computers have led the run up to this Mega cold Easterly starting towards the end of next week,they been rock solid for ages now 

wish we had access to them here (

[SMU]

so even though the evolutions end up very different the diversity is pretty simple & around T96

The mild solutions have the jet moving East through the scandi heights @96, where as ECM / Aperge has split energy going North & south @96 allowing blocking to build-

Middle ground = a UK high/ tame SE flow lets hope we dont go there!!!

[Catacol]

Ho hum - this thread the last couple of days has been a case study in reactivity. The variations in model output ought to make it clear anyway, but just in case it helps to state the obvious: the fluctuations in stratospheric data, and issues with speed of downwelling, means that the models are having a nightmare resolving next week. Add to this Pacific forcing that is losing the high lat signal as every day goes by (falling AAM at present) and the cocktail is complex. Just go and browse the Berlin site for the zonal wind and vortex profile -it is shifting all the time on ECM and as a result the trop pattern is uncertain.

It is still the case that the stratospheric profile indicates height rises to the north. This process has been pushed back a day or so from initial indications 10 days ago... but it is still in place. It is counter intuitive to see a substantial return of the Atlantic, especially given warming of the Canadian vortex shard, and even if falling AAM at the equator helps keep the block more mid than high lat in the short term, the direction of travel remains good. 

Take a deep breath. There are good reasons why the MetO is solid. The only negative for me is the fact that we are so close now to March... but beggars can’t be choosers and as I haven’t seen any snow for 5 years now I am very happy to be a beggar in this current scenario!!!!

Edited February 16, 2018 by Catacol

[Man With Beard]

33 minutes ago, Daniel Smith said:

"The ensembles are a good guidance"

This is probably the biggest flip so far in this entire saga. Unfortunately it's a flip in the wrong direction.

I'm always happy to admit when a theory goes wrong and yes, the GEFS, having been rock solid for 6 days, have ripped my theory to shreds!! Having produced a very good Scandi High anomaly run after run, it trashed it on the 12Z and has not gone back!!

The ECM ensembles, on the other hand, are still keeping to the script! They never went as extreme as the GEFS on the Scandi High, veered slightly run to run, but pretty much stayed bang on for the Scandi height rise after 22nd Feb. And, as one would expect in an anomolous situation, they are growing in strength as T0 approaches.

So I feel the "trust the ensembles" mantra is both holding true and not holding true ... depending on which outcome eventually verifies!

But when you have this short of difference on the MEAN charts at D4 ... you know you're in serious trouble. I mean just where is that Atlantic low on the GEFS?? :o

    

But Hey, it's SSW season!!

We've been here before. We know how it works. Have we ever had a major SSW without the models going loopy? They've all had to do the walk of shame during an SSW in the past.

GFS: 1st February 2009: T168 vs T144

  

ECM: 18th January 2013: T144 vs T96 (!)

  

Even the UKMO: 11th March 2013: T144 vs T120

  

And with that in mind, it's probably worth looking at the T144s this morning and taking a pinch of salt from the saltshaker - then come back tomorrow morning, compare with today, and chances are you'll have a giggle.

[Glacier Point]

EPS and GEFS T850s are like chalk and cheese. I can guess the sort of issues that will be having on trading floors right now ....

There is a continued shift towards a re-invigorated convective signal in the Indian Ocean. Phase 2 MJO.

During December and January, such a trend would be what we have seen overnight from the GEFS and other operationals. 

However, we are not in December or January and we are nearly at March. That poses all sorts of seasonal wavelength issues. GEFS mean days 11-15 remains relatively consistent with the EPS and its previous runs, its just the 850 values being elevated.

GWO phase 2 for March highlights the dichotomy in model interpretations right now..

Let's put that (tropical only) MJO composite against the GWO (tropics + extratropics) side by side for comparison.

Model fog continuing I think, but thoughts would still be for a more genuine -NAO (and associated temperature signal) and more particularly the closer we get to the end of the month.

Edited February 16, 2018 by Glacier Point

[frosty ground]

Icon @ day 4 

Atlantic makes more inroads further north, can the block fight back.

Noticed on the 00z run that the Atlantic does get over the top of the high later on, still leaves us in an easterly / south easterly flow

Edited February 16, 2018 by frosty ground

[Paul]

Hot off the press....

Nick's latest blog, on the model mayhem happening at the moment..

SSW Brings Weather Model Mayhem

[Ali1977]

Well here we go , will we see another wild swing back cold on the 06z. Strangely these changes are at about day four so we’ll know in about 30 mins!! 

[The Eagle]

6z ICON has moved toward the 00z GFS at 120 hrs.

 

[carinthian]

Wow , UK on a knife edge this morning. Cold feast not far away on the ECM run. Looking at the latest UKMO fax chart at 120h ,with a bit of tweaking is not to far off the ECM evolution at the same time. Think this one is still up in the air as so to speak. I think this latest fax is adjusted more to ECM thinking than their own model (UKMO) is showing at 144t. All adds to the uncertainty as to what happens just to the east of the British Isles over the weekend  regarding shortwave development and building of heights thereafter.  Great chart watching this. Must get out ! I have plenty of snow here but desperate you guys to share some soon.

C

 

Edited February 16, 2018 by carinthian

[Ali1977]

1 minute ago, The Eagle said:

6z ICON has moved toward the 00z GFS at 120 hrs.

 

Rubbish model, GFS will move towards ECM then ?

[kingdogleash]

The current SSW still looks on course to bringing just that, (cold and snow for uk) given favourable background state, though we may have to wait until the very last few days of February or early days of March to experience deep cold and snow.

 

 

Quoting Nick here! Great read!

Edited February 16, 2018 by kingdogleash
Accuaracy

[The Eagle]

GFS moving toward ECM at 48 hours.

Jeez, can't believe I just said that. 48 hours? lol

[Ali1977]

2 minutes ago, The Eagle said:

GFS moving toward ECM at 48 hours.

Jeez, can't believe I just said that. 48 hours? lol

At T54 the Atlantic profile is more vertical than the last run, Atlantic getting held back so hopefully ridge of HP has more chance of followings ECMs run

[steveinsussex]

People are going to trust the ecm after the apparent over night data issues?! 

[SMU]

at 60 the jet is more amplifed & atlantic weaker in eastward progression

[Paul]

1 minute ago, steveinsussex said:

People are going to trust the ecm after the apparent over night data issues?! 

They wouldn't have put it out if the data issues were still present, it was simply a delay.That said, I'd not put trust in any model beyond 72 hours right now. 

[Scandinavian High.]

ECM has nailed it gfs will move towards ecm ..

[weirpig]

Certainly better heights on the gfs at t72   (great this model watching)

[booferking]

UK High is the form horse in these situation thats were i think this will end up ECM correct itself slightly later on.

GFS has moved slightly to the ECM we will get the middle ground outcome.

Edited February 16, 2018 by booferking

[BLAST FROM THE PAST]

well it shouldn’t be long before we see where we are headed.....for next 10-15 days .  Looking at all the models and for the U.K. t96 is the crux point.  Block to E / NE with little trough nudging continental E flow into SE U.K.....  ECM goes full on and for me worst is UKMO and it seems to discount any continental flow.  Others delay but with door of opportunity remaining open for down the line.....I say beginning of March....as the wrestling match continues.   I want to be with the ECM....but my instinct is telling me yes to t96 set up, as per most models but after that middle ground as the wrestling match continues for a wee while yet.  

I hope the ECM has played a blinder.....but each model that proposed to play that blinder this winter the Synoptics have failed to execute fully....and middle ground comes to fruition.

 

BFTP

Edited February 16, 2018 by BLAST FROM THE PAST

[frosty ground]

Looks like a clean break with no energy leaking east