Model Output Discussion 18th Nov.2013-12z onwards.

[SMU]

Snowman-

 

A deeper low would move further North- so more than likely the 12z is to flat - the UKMO looking better with a smaller system that will slide SSE on a better trajectory for amplification.

 

S

[Cheshire Freeze]

GFS FI.....vortex moves from Siberian side to Canadian side then starts to wander back across to the Siberian side as the run comes to a conclusion....with a rinse and repeat pattern of increasing heights towards Canada on the last couple of frames. There's one thing about it, the vortex looks to be getting a tough time in settling.

[MR EXTREMES]

so that's two models that have changed ukmo and gfs like I said I don't buy into anything beyond t144 and as I said the ukmo is the best model by a country mile and that's already taken steps back and the gfs don't like good either into fi so everything held back once again.

[swfc]

-4 850S heading to the canaries via north africa while we bask in +8 in deep deep fi 

[SMU]

FWIW

 

I think this will be the landing strip at day 61/2

 

http://modeles.meteociel.fr/modeles/navgem/runs/2013112712/navgemnh-0-156.png?27-17

 

S

[nick sussex]

Then you do see it?

Yes if it tracks SE and if the timing is right it will help. Here it is with its fellow traveller at 144.

 

 

The problem is shortwaves just complicate the picture and give more chances for things to go wrong, if you can guarantee it will behave itself though then I'm in.

The UKMO also has a shortwave near Newfoundland so it does look like that will have to run east , the UKMO looks a bit more messy upstream than the GFS, for those wanting cold its going to have to be some shortwave drama. As long as you get that amplifying wave upstream this should be okay, did I really say that!!!

 

What we want is the GFS solution with a bit more amplification and it could get interesting.

[Cheshire Freeze]

I think the important thing to note here, especially going forward, is that as long as that Pacific ridging is maintained, the vortex will have a tough time residing towards the Canadian sector. In theory this could set up a rinse-repeat of N'ly patterns in the mid-long term. Obviously, as surface low heights are repeatedly attacked by WAA on the Pacific side (and at times in the N Atlantic sector), things could get very interesting as we head through December and towards January.

 

All conjecture for now though...

[Mucka]

The UKMO also has a shortwave near Newfoundland so it does look like that will have to run east , the UKMO looks a bit more messy upstream than the GFS, for those wanting cold its going to have to be some shortwave drama. As long as you get that amplifying wave upstream this should be okay, did I really say that!!!

 

What we want is the GFS solution with a bit more amplification and it could get interesting.

 

 

Agreed but no way to be sure on the timing, development and therefore behaviour of it so yeah maybe a little drama is inevitable but I'm not keen with the way GFS Op's have made more of it as the day has gone on. Maybe I'm just a coward because as Snowman mentioned it could help as well as hinder. It may even get ironed out again anyway in future output so I'll just cut back a little on my caffeine intake until then.

 

GEM

 

 

NAVGEM

 

Edited November 27, 2013 by Mucka

[Methuselah]

The ENSO's connected to the AO; the AO's connected to the NAO; the NAO's connected to the MJO...Hear the word of the Lord!

[Cloud 10]

A much more prominent pacific ridge from the UKMO at 144 hrs compared to GFS

 

ukmo..  gfs..

 

 

 

[picog]

FWIW I think this will be the landing strip at day 61/2 http://modeles.meteociel.fr/modeles/navgem/runs/2013112712/navgemnh-0-156.png?27-17 S

Would that give the UK an Easterly. An easterly laden with snow?

[Yarmy]

Agreed but no way to be sure on the timing, development and therefore behaviour of it so yeah maybe a little drama is inevitable but I'm not keen with the way GFS Op's have made more of it as the day has gone on. Maybe I'm just a coward because as Snowman mentioned it could help as well as hinder. It may even get ironed out again anyway in future output so I'll just cut back a little on my caffeine intake until then.

 

GEM

 

 

NAVGEM

 

 

Good agreement between the NAVGEM and NAVGEM there, Mucka. 

[Mucka]

Would that give the UK an Easterly. An easterly laden with snow?

 

 

Yes at day 10 and Santa would ride in on a snow drift bearing gifts for one and all. 

Good agreement between the NAVGEM and NAVGEM there, Mucka. 

 

Doh! 

Just seeing who was paying attention, honest.

[Captain Shortwave]

Yes at day 10 and Santa would ride in on a snow drift bearing gifts for one and all. 

Except those who have been bad and would only get cold rain 

[Tamara]

The ENSO's connected to the AO; the AO's connected to the NAO; the NAO's connected to the MJO...Hear the word of the Lord!

Perhaps we could hear what your opinion of the model output is and how the pattern might evolve?  I guess that applies to others who jest at the abbreviations but don't add any contribution of their own?

Edited November 27, 2013 by Tamara תָּמָר

[bluearmy]

GEM 12Z fails to retrogress the block due to the depressions in the w atlantic breaking through and deepening markedly. that leaves europe under high heights and the northerly becomes a wnw and fails to make it much further south than scotland with the cold uppers!

[Tom Jarvis]

GEM 12Z fails to retrogress the block due to the depressions in the w atlantic breaking through and deepening markedly. that leaves europe under high heights and the northerly becomes a wnw and fails to make it much further south than scotland with the cold uppers!

GEM isn't fully out yet

[Joe Levy]

GEM 12Z fails to retrogress the block due to the depressions in the w atlantic breaking through and deepening markedly. that leaves europe under high heights and the northerly becomes a wnw and fails to make it much further south than scotland with the cold uppers!

Correct me if I'm wrong, but the 12z GEM hasn't finished running yet. At least on meteociel it hasn't

[Mucka]

Absolutely nothing in GFS ensembles to suggest anything other than a cold snap, the Op was probably one of the better runs in fact.

That said it's only one run.

[Captain Shortwave]

Well here is the day 8 chart from the GEM, 

Nuff said really

[Joe Levy]

Well here is the day 8 chart from the GEM, 

Nuff said really

The contrast between the 12z and the 0z on the GEM is quite extreme at this point - that low pressure to the south-east of Greenland is massive... In any case this is one run and not a run that fits with other models, on this particular detail at least

[Gavin Hannah]

Make a note your diaries for the weekend of the 7th and 8th of December.

 

 

I'm banking this chart. 

 

ECM at 240

GFS at 240

Edited November 27, 2013 by IBringTheHammer

[Ian Brown]

Ian,

 

What is the proof of this? Not discrediting your above statement, but I have never seen the data to prove it.

 

The bottom line is, there is no mild weather shown on any of the charts for anytime soon, so it's confusing to other members to see this debate going on, all the way out to T384.

 

 

Glenn, you have been around a long enough to know how many let downs there have been over the years, we have even had the ECM at T96-120 showing bitter cold easterlies that have never materialised. If we are in a cold/average set-up and the models show mild at T120-T144 we know its virtually in the bag.

 

Of course recent years have seen some of theses cold synoptics verify, but we only have to look back at last December for one of the biggest failures of all, a double whammy of no easterly and then the Atlantic returning within a couple of days of when the easterly should have been happening. Even the northerly early last week totally changed from what the NWP was showing at T144-T168, so we can expect further changes. Of course prior to 2009, I could look at the models and think where can this go wrong ? Or look at a particular run and see the chink in the armour, and that is what would end up happening. 

Well here is the day 8 chart from the GEM, 

Nuff said really

 

Not sure why people place any faith in the GEM.

[EML Network]

It's a case of take your pick from the ensembles suite !!

 

Plenty of options from the 12z GFS showing a route to a decent cold spell with snow potential for many. 

 

I still think personally that the Low pressure system will drop well East of the UK, giving us just a brief flirtation with cold down the East of the UK. 

 

I think the control run is on the money..

 

The award for the most confused perturbation GFS run of 2013 goes to perturbation 12...it's  a bit like a question of Sport's ''What happened next'' ...

 

Lots of interesting charts on offer but cool | cold  zoneality from the NW is still clearly the form horse with High pressure thereafter exerting an influence from the SW, bringing an all too quick return to milder weather taking us into W|C 9th Dec ??

 

[Man With Beard]

Make a note your diaries for the weekend of the 7th and 8th of December.

 

 

I'm banking this chart. 

It's a cracker. The consistency of the GFS and ECM have been remarkable for something so far out. But still a long, long way away. An easterly push of the pattern of just a few hundred miles will leave us in the dry bit. Waiting until T120 really.