Model output discussion - 5th December 2016 - Into Winter we go

[stewfox]

7 minutes ago, Steve Murr said:

KABOOM

Perfect wedge splitting the jet - note the 2 lows - just like 2010- 1 low either side of the GH ( NW side & SW side )

Can you clarify what we are looking for , to happen ?

I have circled the two lows I assume you refer to.

Edited December 28, 2016 by stewfox

[Stuie]

Going back to T120, look at the heights W, NW and far West. Maybe this blocking scenario could come off!

[Purga]

Omega, Omega wherefore art thou Qmega?

Steve M - energy going under to create a cut off High?

 

[Weathizard]

Beautiful but once again, it's at day 10.... Once bitten, twice shy. You just know as it gets towards a reliable a laminate floor little shortwave will pop up and ruin it, there is a reason why cut off GH are so rare.

[mpkio2]

Wow, I go away for about a month or so, and so much has gone down!!

What with the models showing so much promise near beg Dec, only to be leading us all up the garden path (The story of Winter so far!!!)  and a much more benign pattern set-up instead (Not balmy mild though!), leaving us now in a very quiet anti-cyclonic set-up with the Euro-Slug that has pesisted throughtout most of the month still near by:

The most fascinating thing I find with this December is how blocked its been with wanning off any Atlantic onslaught ...

Of course, we have had some rain and wind due to the two storms over the Christmas period, but nothing on the scale of what you would exspect in an avarage December. And even under these circumstances, we have had some chilly temps. For example, this is where we currently stand with the NWP:

Yet, most of Central England will be near freezing temps tonight :

Might point is that we could have had it alot worse than what could have happenned, esepecially when looking at the strong positive AO and strong PV over the pole. Do I have to show you last Decemeber?

Yes, I do!!!

Anywho, on to what is currently being shown in the models for next Cold shot.

12z GFS t120:

12z GEM t120:

12z UKMO t120:

12z ECM t120:

As can be seen from above, there does seem to be some sort of agreement for some form of Mid Atlantic High (Better than nothing! ). How this high setups up, how strong it will be, its oreintation and how strong of a Notherly/North Westerly will affect us, is all still, literally, up in the air, with inter-model changing these details - for now the 4 main miodels have sided in twos - ECM/GFS vs UKMO/GEM! Game on! 

As some other more knowledgable posters have already mentioned ( @Glacier Point and @Tamara, ), there are some small signs of some more favourable background signals that might start to play their part and help our chances in amplifying the pattern (MJO moving to Phase 8/1/2, GWO orbit phase 2, etc,). But caution, as has been warned most assertively this Winter, is warranted here. These things all need to fall into place at the right time in order for us to take advantage of the evolving pattern.

The disconnect between both the GEFS and EPS and their Operational runs is also a big concern. Either one could be wrong to a certain degree, but, just as likely, they could also be, as others have mentioned, "firming up" on the evolving pattern and how it will play out, seeing to all the options on the table that could occur.

What do I think? I thinks its best to sit back and wait. I truly think that New Years Day (When the Mid Atlantic High forms to our west,) is the tipping point. So for me, anything after t120 (For now,) is FL. Until the models come to some sort of an agreement, everything is just for fun.

Let the rolloer-caoster continue on!!!!!

~mpkio2~

[Ali1977]

Shame we don't get GLOSEA info anymore - BBC long range would start picking this up soon though if correct

[snowwman]

2 minutes ago, Purga said:

Omega, Omega wherefore art thou Qmega?

Steve M - energy going under to create a cut off High?

 

For coldies, an excellent ECM run, and the GEFS output is decent, too, even to day 16.

[radiohead]

ECM ENS will be interesting....

[swfc]

Maybe its my age but that ecm run looks to smooth to me from start to finish.such a void within the other models id be very wary indeed .hope im wrong and just for once things fall for the uk

[Frosty.]

I would love to think that T+96 is just a dress rehearsal for T+240 on the Ecm 12z because day 10 is a peach for coldies and there would be snow around too.

[tight isobar]

Stunning ecm 12z..

Will new support though!!??

And yes if verify. .its a stern northeast/easterly soon to follow. .and mass opportunity for mass impactual convection. ..ie..snow showers..probably merging to spells of snow. ..However. .lets see support! !!

[SMU]

13 minutes ago, stewfox said:

Can you clarify what we are looking for , to happen ?

I have circled the two lows I assume you refer to.

Hi the bottom left one is correct the other one is left of greenland-

when you get high pressure forcing NW towards greenland for a proper greenland high you always get a seperation of energy ( like cutting a grapefruit in half ) the more amplified the split the further apart North/south the systems are- 2010 is still the BEST chart for 2D vertical advection-

but referring to my earlier post - the more high pressure we keep in situ @ 144 alongside the PNA ridge moving of the coast of the NE US we create a stable High south of Greenland 168-192.. which forces North - hence the split energy 192-216...

The wheels are in motion at 168 so its not total F1, November 2010 was the same - once that chart varified then 3 days later the cold 99.9 guarenteed....

S

[ArHu3]

1 minute ago, swfc said:

Maybe its my age but that ecm run looks to smooth to me from start to finish.such a void within the other models id be very wary indeed .hope im wrong and just for once things fall for the uk

I hate these perfect +192h charts, you know they will never verify. I'd rather have flawed because change which is certain to occur could improve but from perfection there is no upgrade only downgrade 

[Gibby]

Now even I'm getting more interested. This chart is much more what I've been looking for even better as it comes from my preferred model. Note the undercut out of the states can only go under the High because of its blocking attributes further North than recently. Further out charts would probably show a Southerly positioned Jet flow across the Atlantic towards Iberia which could feed a battleground scenario from the SW longer term. A long way out but this chart offers a real chance of a substantial cold outbreak from that setup. Let's hope the ensembles later show a shift towards a similar evolution and this better orientation and position of the High pressure is maintained over up and coming runs.

http://old.wetterzentrale.de/pics/Recm2401.gif

[blizzard81]

2 minutes ago, Gibby said:

Now even I'm getting more interested. This chart is much more what I've been looking for even better as it comes from my preferred model. Note the undercut out of the states can only go under the High because of its blocking attributes further North than recently. Further out charts would probably show a Southerly positioned Jet flow across the Atlantic towards Iberia which could feed a battleground scenario from the SW longer term. A long way out but this chart offers a real chance of a substantial cold outbreak from that setup. Let's hope the ensembles later show a shift towards a similar evolution and this better orientation and position of the High pressure is maintained over up and coming runs.

http://old.wetterzentrale.de/pics/Recm2401.gif

If the ecm ensembles fall through the floor tonight then it may just be game on.

[West is Best]

Well well well this is very interesting. Wow, this fills me with hope. The op is way to the milder side with some significantly cold perturbations:

 

[bluearmy]

would love to see some consistency from the ops late on in their runs but I guess that's why they are ops. If the eps revert to yesterday's 12z offering then we have bi polar eps aswell! At least the last two GEFS have churned out cold means post day 8 but they haven't been the same amplification so more inconsistency ! 

At least we can say is that we are getting fi ECM ops that are not out of sync with previous eps output. And we are still seeing op upgrades so we are still some time away from throwing in any towels. A less than exciting eps suite in an hour may well dumb down the atmosphere in here! 

[Snowmaggedon]

Blimey, you know it's time to sit up and take notice when even Gibby gets on board. This reminds me of the evening of THAT ECM!

[IM NOT REALLY HERE]

6 minutes ago, West is Best said:

Well well well this is very interesting. Wow, this fills me with hope. The op is way to the milder side with some significantly cold perturbations:

 

Even the mean stays below -5 for a good while. Things are looking up. 

[Mucka]

A lot will depend on the behaviour of the Azores low and how it interacts with the upsteam pattern. If it goes North and phases with the trough digging South it will be difficult to maintain decent amplification. If it stays trapped to the South and is forced West and merges with upsteam Atlantic trough later it would be better.

 

ECM is on a knife edge at 168 but manages to split the energy so that most goes West and just a little phases with the trough before the door is closed.

There are an infinite number of possibilities here, not to mention the complexity of the pattern before this, so I'm not expecting tow day 8 op charts to look the same at the moment let alone expecting anything later to verify.

It is edge of seat viewing for weather geeks, I just hope we end up with something like ECM, I feel we deserve some decent winter weather after the endless drudge we have had to endure over the last few Winters and so far this year.

Hoping ECM ensembles back the Op but one of the biggest surprises and oddities is the small amount of scatter from day 10 in GFS ensembles, especially when there is plenty from day 6 to 10!

Edited December 28, 2016 by Mucka

[mpkio2]

Wait, where have I seen that familiar 12z ECM t240 chart...?

Oh yeah! Here...

I'm sorry I had to!

All for fun peeps!

~mpkio2~

[feb1991blizzard]

6 minutes ago, bluearmy said:

would love to see some consistency from the ops late on in their runs but I guess that's why they are ops. If the eps revert to yesterday's 12z offering then we have bi polar eps aswell! At least the last two GEFS have churned out cold means post day 8 but they haven't been the same amplification so more inconsistency ! 

At least we can say is that we are getting fi ECM ops that are not out of sync with previous eps output. And we are still seeing op upgrades so we are still some time away from throwing in any towels. A less than exciting eps suite in an hour may well dumb down the atmosphere in here! 

I wouldn't worry about the ops in FI, unless early on in the run they are totally without support, I would happily take the GEFS or the EPS from the other day, like you say though, we need a bit more agreement between the suites as to the details of any blocked cold patterns, I'm not overly bothered if the ops are all outliers offering different solutions late on in the run as long as ens are rock solid.

[Frosty.]

Well I gotta say it's about time an Ecm day 10 chart comes true, so many false dawns leading coldies up and down the garden path..just verify already dammit!

[Man With Beard]

25 minutes ago, West is Best said:

Well well well this is very interesting. Wow, this fills me with hope. The op is way to the milder side with some significantly cold perturbations:

 

As BA mentions above, the ECM D10 has ensemble support of a kind, and has had more than a little ensemble support from the ECM D11-D15 ens in recent days (slightly less this morning). So it is a very viable option. 

But with GFS/UKMO ops not quite there, still a little way to go on this conundrum

[weatherguy]

Wonderful +216 and +240 ECM respectively.

Can't say I'm convinced just yet though, model watching recently has felt like reading tarot cards...Can only comment on what the charts show, mind, and this is a textbook 2 pronged attack on the Trop PV, wonderful if it comes off