Model output discussion - Winter approaches

[Zak M]

8 minutes ago, dragan said:

Timothy, this is nor the time or place, for this is model output discussion. Keep tuned for more pearls of wisdom however, you may learn a thing or two. 

I love how you just called him 'Timothy'

Are you his father?

Edited November 14, 2020 by Zak M

[Mark wheeler]

Watching quietly in the background at the moment , Great to see @nick sussexposting in this thread again . Plenty of promise for sure . 

[Zak M]

@Uncertainy Wow Josh! Very good and informative post, please keep it up!

I agree with you and Nick re. how uncertain next week will be. You will see all these winter nirvana charts popping up circa day 10, but it's highly likely that they will disappear the day after!

I'm waiting for the ECM clusters to come out. Interested to see how many members go for the colder solution over NW Europe at day 9 and 10, like the op did.

Edited November 14, 2020 by Zak M

[swfc]

Block collapsage and vortex depreciation I'm at a loss. Has the planet finally been invaded. Anyway guess the ec 12z euphoria has eased. Like nick said its verification stats do carry a health warning esp with easterlies. Good upgrade but see what tomorrow brings threw all output. I'm off to catch up on my klingon,

Edited November 14, 2020 by swfc

[Mike Poole]

40 minutes ago, Uncertainy said:

Evening all

I think we’ve got good agreement on the Synoptics up to around day 6 or 7. A node of  heights amplifying around Greenland and then tumbling down through the U.K. All models then have another low approaching and possibly disrupting against that little wedge, but the nature of this interaction and the subsequent amplification (or lack of) is presently unclear.

The GEM for example, does disrupt the low under the wedge to some extent but then it sort of hangs around near the UK and the next low follows quickly from the Eastern Seaboard with little amplification in between.

Agree with the comments above vis the ECM, nice evolution but it’s got serious history of day 9-10 garden path highs.
Still, it’s not completely unsupported by the 240 mean from earlier on and perhaps more so on the latest mean. The GFS at a similar time frame also toys with a Scandi high. As Nick rightfully points out, it’s a precarious evolution to get there and thus, unlikely to be there tomorrow morning.

I think the form horse this evening is a cooler, unsettled outlook with systems perhaps taking a more negative tilt. There is certainly scope for amplification after that, but it’s been so long since a chart like the day 10 ECM actually happened during late autumn / early winter that I struggle to put any faith into it!

The MJO’s expected evolution from phase 1 to 2 and then into the COD also supports these ideas to some extent. 

One thing does  seem clear though is a disconnect between the borderline rampant upper strat and the troposphere, as long as this continues, the game remains on.

This is why I think any cold chances are either early to mid December, before the strat and trop vortices couple, and much later into Feb, after an SSW.  Zonal winds in the strat are already high:

Disconnected with what we see down here, but it is only a matter of time before they connect, can we squeeze a cold spell before this happens?

Edited November 14, 2020 by Mike Poole

[Uncertainty]

The wait is over Zac!

 

2 outta 3 ain’t bad! 

@Mike Poole we really could do with verifying that Scandi / Urals high to perturb this burgeoning vortex. Otherwise as you say it’s only a matter of time until...

Just for once in our lives could we have that chart inverted!!!

[Nick F]

Not just a one off the idea of a Scandi/NW Russia high expanding westward, the models having been dropping hints in the medium range on and off and in various shapes and strengths for a few days now. And there's enough leeway in the ensemble guidance to support the idea too. Need the Atlantic trough to back off to the west - otherwise if it's too close we end up with mild southerlies or southeasterlies. Just hope the trop remains detached from the rapidly strengthening strat PV.

Edited November 14, 2020 by Nick F

[feb1991blizzard]

31 minutes ago, Mike Poole said:

This is why I think any cold chances are either early to mid December, before the strat and trop vortices couple, and much later into Feb, after an SSW.  Zonal winds in the strat are already high:

Disconnected with what we see down here, but it is only a matter of time before they connect, can we squeeze a cold spell before this happens?

Yes, my preliminary thoughts - cold early and late (although unlikely to be brutal cold early) - middle period nitto

[BlueHedgehog074]

19 minutes ago, Uncertainy said:

 

Just for once in our lives could we have that chart inverted!!!

Looks like your dream will come true...

[Uncertainty]

6 minutes ago, Nick F said:

Not just a one off the idea of a Scandi/NW Russia high expanding westward, the models having been dropping hints in the medium range on and off and in various shapes and strengths for a few days now. And there's enough leeway in the ensemble guidance to support the idea too. Need the Atlantic trough to back off to the west - otherwise if it's too close we end up with mild southerlies or southeasterlies. Just hope the trop remains detached from the rapidly strengthening strat PV.

Yes Nick, yesterday’s 12z GEFS were particularly keen. It’s just that there have been so many amplification busts in the 8+ day range in recent months that I’m highly sceptical until proven otherwise! (Unless the amplification is mid Atlantic based in summer then it’s a given, of course!)

 

[sheikhy]

Icon 18z not good again!!lets hope gfs cheers us up!!not holding my hopes up though!!

[Uncertainty]

1 minute ago, DiagonalRedLine said:

Looks like your dream will come true...

I think this forum would self destruct if that happened!

[Chesil View]

I know we often chase the 87 style long fetch easterly but for my money I,d always go for a greeny /Iceland/Svalbard high for longevity and a more widespread snowy outcome. 

Scandi highs if they don't sink nearly always retrogress to Greenland anyway in our great winters so why not cut out the middleman.

I would prefer to wait that bit longer for the GFS out come with the negatively tilted trough rather than the face to face high east low west combo.  The GFS outcome had genuinely cold uppers sliding round the back of the high  and support from lows heading east into Europe.

The ECM has none of this and to me looks as if the high would sink with slightest bit of eastward pressure from the Atlantic.

Just my take.......we shall see.

Edited November 14, 2020 by Broadmayne blizzard

[SMU]

Not even a glimpse of a cold spell on the 18z GFS.

Zonal all the way barring  a 12 hour Northerly flow in the week.

[northwestsnow]

Could come good later on Steve?

[feb1991blizzard]

3 minutes ago, Steve Murr said:

Not even a glimpse of a cold spell on the 18z GFS.

Zonal all the way barring  a 12 hour Northerly flow in the week.

Hang on a minute - there is a wedge about to ridge up towards Iceland, could be a stonking end to the GFS.

[Griff]

9 minutes ago, Steve Murr said:

Not even a glimpse of a cold spell on the 18z GFS.

Zonal all the way barring  a 12 hour Northerly flow in the week.

I'm watching it and it seems remarkably similar to the previous run, waiting to see if heights evolve similarly in FI...

 

Meaningless this far out but interesting in terms of consistency... 

Edited November 14, 2020 by Griff

[Anthony Burden]

What a big difference between models gfs low pressure all the way,ecm high pressure oriented.

We will get a better idea tomorrow,my feeling would be on ecm because of the met office thinking

regarding high pressure,not to say that ecm 240 hrs will turn out exactly as shown,but all the same 

I no what outcome I prefer.

[Griff]

More similarities than I would have predicted, obviously some differences at 240

[northwestsnow]

Vortex shattered everywhere...

[Allseasons-Si]

1 hour ago, DiagonalRedLine said:

Looks like your dream will come true...

That's a cool high

now come on,have you been in Knockers crayon draw

 

[damianslaw]

I said earlier today, fully expected at least one GFS run (in future runs this weekend) to go with a raging SW feed, and alas 18z has taken the bait, probability of 1 GFS run in 4 doing this, perhaps 99%... (its so predictable..)

[northwestsnow]

Are we going to see a classic Nina footprint on 18z?

Ie scandy trough ,Atlantic blocked?

[Cheshire Freeze]

3 minutes ago, northwestsnow said:

Are we going to see a classic Nina footprint on 18z?

Ie scandy trough ,Atlantic blocked?

Yep, about to see big N Atlantic heights post 270 hrs but it's all just for fun at that range!

Still only mid Nov, so plenty of time for the house to get in order in time for winter proper

Edited November 14, 2020 by CreweCold

[Allseasons-Si]

6 minutes ago, northwestsnow said:

Are we going to see a classic Nina footprint on 18z?

Ie scandy trough ,Atlantic blocked?

Watching those heights build off the NE'ern states off Newfoundland,this could be our next opportunity.

Edited November 14, 2020 by Allseasons-si