Model Output Discussions 12z 01/09/2016

[MR EXTREMES]

No solar activity,

weak vortex,

weak jet stream weak Atlantic warming strat perhaps a Canadian warming this winter.

I will not be suprised if we see much more northern blocking.

[johnholmes]

1 hour ago, MattHugo said:

Given general model guidance and the overal signals from the EPS then, for now at least, it is the milder more W or SW'ly type that is 'most likely'. Clearly in meteorology there is always scope for another option, so certainly a few more model runs required to determine whether the more anticyclonic, colder regime is indeed maintained across the UK throughout most of next week, or whether a milder flow arrives from the W or SW. The spread becomes evident from next Tue/Wed but note for Reading at least the 00Z EC HRES (Deterministic) whilst at the bottom end of the spread isn't, overall, an outlier in terms of 850mb temps, but certainly some difference between CTR and HRES.

Compared with the likes of the GEM and the GFS mind from 00Z then it certainly is an outlier...

http://meteocentre.com/models/compar_models.php?map=eur&lang=en&size=large&run=00&stn=PNM&&range=long&type=sidebyside&hh=240

My money is on the block being removed circa Tue/Wed of next week...as things stand!

Matt.

I have to say Matt I remain far from convinced that Exeter are going to go down the milder option. Obviously they (and you) have access to far more than I have. But looking at the outputs that are available to me then I would suggest that 'mild' or even 'rather mild' will not feature much if at all in any forecast from them out to Wednesday at least, probably not beyond that for next week either. On the balance of model output there 'may' be a temporary less cold outlook beyond next week and this is suggested in the latest 500mb anomaly charts available. How temporary or whether it is the start of a more mobile Atlantic is far from clear to me, as of now.

 

[SMU]

44 minutes ago, booferking said:

Any idea what the uppers would be incoming from this chart please?

london which is on the light blue line is

~ 542 along the 1015 line - so ~ -5c

Norfolk which is just touching colderair

~ 538 along the 1018 line - so ~ -7c

S

the dark blue blob over the near continent

532 / 1020 = -11c

Edited November 3, 2016 by Steve Murr

[feb1991blizzard]

2 minutes ago, Spah1 said:

Nope that's not it. 

That means it comes out on NW at 5pm, its fully out by 4.30 on meteociel every day and has been for donkeys years.

[Spah1]

Cheers

[booferking]

2 minutes ago, Steve Murr said:

london which is on the light blue line is

~ 542 along the 1015 line - so ~ -5c

Norfolk which is just touching colderair

~ 538 along the 1018 line - so ~ -7c

S

Thanks..

[feb1991blizzard]

1 minute ago, Steve Murr said:

london which is on the light blue line is

~ 542 along the 1015 line - so ~ -5c

Norfolk which is just touching colderair

~ 538 along the 1018 line - so ~ -7c

S

With colder to follow if it fully undercuts and draws the Easterly in.

[northwestsnow]

10 minutes ago, feb1991blizzard said:

With colder to follow if it fully undercuts and draws the Easterly in.

http://old.wetterzentrale.de/pics/Rukm1441.html

Finely poised, could go either way,if i were being picky i'd be suggesting the azores high MIGHT be the spoiler moving forward, maybe steve has his own thoughts, he has been pretty damn spot on so far..:D

Edited November 3, 2016 by northwestsnow

[BLAST FROM THE PAST]

Yep we are here at similar junctures as in past years.  Something to back down or halfway house.  I'm edging towards a halfway situation

 

BFTP 

[knocker]

I comment not on the GFS run merely to say a fine example of the interaction of the warm and cold air causing a strengthening of the thermal gradient resulting in a 150kt jet

 

Edited November 3, 2016 by knocker

[Singularity]

It is starting to appear that as Steve M said earlier, GFS' tendency to 'smear out' the potential vorticity may be its downfall with respect to how next week pans out.

Once you get a nice division between the Atlantic and Svalbard-region troughs, the door is wide open for the  N. Eurasian ridge, bolstered by snow/cold feedbacks, to really wedge itself in. Not only does this keep us dancing with the cold continental air, but it acts as a mighty 'brick in the washing machine' that the polar vortex really won't enjoy. Given how interesting the GFS strat. chats have been in lower-res lately even without that extra brick, I can imagine some seriously inspiring charts if and when the model switches to a long(er) lived N. Eurasian ridge.

I wish I didn't have to say if, but when it comes down to it weather prediction beyond 4-5 days is playing with dice that are loaded in often mysterious ways.

[knocker]

The latest from the woodshed this evening is that the GEFS anomaly tonight is showing an increasingly tight upper westerly flow that could well indicate a period of some stormy weather.

The pattern is fairly familiar but with some developments. The ever present Aleutian low with strong WAA into NW North America but now with a well developed Canadian/Greenland vortex with trough aligned to Iceland, which, with some help from the Azores HP. is tightening the thermal gradient.across the Atlantic, and not to forget the trough over the eastern seaboard which remains an important player in this scenario. To complete the picture we have the trough to the east and the Russian HP ridging into the Arctic.

Looking further afield, which frankly I think is pushing it at the moment, but the GEFS is indicating some retrogression which wasn't a million miles away from the EPS thinking this morning

Edited November 3, 2016 by knocker

[Met4Cast]

ECM thus far sticking with it's guns with heights building over Scandi - Can it split the energy Southwards under the high though

[tight isobar]

Jma/ecm..12z...

A pattern emerging? 

[Met4Cast]

Yes. Yes it can disrupt. 

[Ali1977]

What are you playing at ECM!!

[northwestsnow]

Gripping stuff!!

ECM refuses to back down!

http://old.wetterzentrale.de/pics/Recm961.html

http://old.wetterzentrale.de/pics/Recm1201.html

http://old.wetterzentrale.de/pics/Recm1441.html

But will the Atlantic finally break through next?

[fergieweather]

1 minute ago, Ali1977 said:

What are you playing at ECM!!

It'll be fascinating to see if this ultimately goes the recent GloSea route (slack low established across UK into mid-month)...

[karlos1983]

2 minutes ago, Ali1977 said:

What are you playing at ECM!!

Dog with a bone springs to mind! Let's hope we get to the marrow!! 

[snowgirl30]

When are we starting a new thread mods? Lots of pages in this one lol 

[Frosty.]

Wow this is impressive from the Ecm 12z...wot atlantic breakdown!.. look east Next week looks colddd

Edited November 3, 2016 by Frosty.

[Ali1977]

1 minute ago, fergieweather said:

It'll be fascinating to see if this ultimately goes the recent GloSea route (slack low established across UK into mid-month)...

What would that mean for the U.K. If it were to end up like that - dull and chilly? 

[feb1991blizzard]

4 minutes ago, fergieweather said:

It'll be fascinating to see if this ultimately goes the recent GloSea route (slack low established across UK into mid-month)...

If it does then the next question on everybody lips will be could evaporative cooling come into play?

[karlos1983]

Mouth watering eye candy ECM. Very naughty

T'would be chilly too 

Edited November 3, 2016 by karlos1983

[northwestsnow]

1 minute ago, feb1991blizzard said:

If it does then the next question on everybody lips will be could evaporative cooling come into play?

Old skool November on the cards, and i love it !! (Doesn't mean snow, but it means cold foggy and frosty )..

PS If ecm has the right handle, and i'm not sure we will know until maybe the 00z runs tomorrow