Model Output Discussions 06z 04/11/16

[swfc]

id agree with ba that post 150 hrs things are indeed a bit of a dogs dinner.also tho the nhp is in a good place for november and a big plus is theres nothing in the outlook that shows anything regarding the atlantic moving in as such.not a bad place to be imo.all to play for tom

Edited November 15, 2016 by swfc

[Banbury]

12 minutes ago, swfc said:

id agree with ba that post 150 hrs things are indeed a bit of a dogs dinner.also tho the nhp is in a good place for november and a big plus is theres nothing in the outlook that shows anything regarding the atlantic moving in as such.not a bad place to be imo.all to play for tom

Totally agree and that is a damn good starting place for the start of December

[Snowman.]

Clear shift in the GEFS in support of the OP, now we have this new trend tomorrow will be where it can get us. 

Speaking in terms, I actually wouldn't mind a delay if that would mean a colder source of air to tap into instead of having A+ synoptic in -4 to -6 850s. 

[Banbury]

Control very close to something very good

[feb1991blizzard]

10 minutes ago, SN0WM4N said:

Clear shift in the GEFS in support of the OP, now we have this new trend tomorrow will be where it can get us. 

Speaking in terms, I actually wouldn't mind a delay if that would mean a colder source of air to tap into instead of having A+ synoptic in -4 to -6 850s. 

GEFS going to end up with some stonkers though.

 

2 minutes ago, Banbury said:

Control very close to something very good

A few are close to something very good.

[Frosty.]

The GEFS 18z mean looks wintry towards the end of November with a scandi trough, height rises to the NW and the Atlantic looks blocked. The uk would be in a cold airmass with Nly / NEly winds..this looks very good again for coldies!

Edited November 15, 2016 by Frosty.

[fergieweather]

44 minutes ago, feb1991blizzard said:

The thing is though, the PV just isn't ramping up, blocking keeps prevailing or looking like prevailing, strat vortex destroyed, if this keeps happening we will hit the jackpot at some point, think about this as well, if we keep delaying it but keeping it on the cards, there will be better uppers to tap into, the further into winter, the more of a stonker it will be.

....unless, of course, the stratospheric PV suddenly goes on steroids later Dec/&/or on into Jan and we see a marked switch from an exceptionally weakened state into early winter, to a stronger than average one thereafter. Caution needed re extrapolating current PV status as definitely characterising how it will behave all of this winter...

[Cheshire Freeze]

Just now, fergieweather said:

....unless, of course, the stratospheric PV suddenly goes on steroids later Dec/&/or on into Jan and we see a marked switch from an exceptionally weakened state into early winter, to a stronger than average one thereafter. Caution needed re extrapolating current PV status as definitely characterising how it will behave all of this winter...

That is my main fear Ian..and the reason I want to exploit this weak PV as soon as we possibly can. It's all good and well saying patience required...but it doesn't always work that way...

[feb1991blizzard]

5 minutes ago, fergieweather said:

....unless, of course, the stratospheric PV suddenly goes on steroids later Dec/&/or on into Jan and we see a marked switch from an exceptionally weakened state into early winter, to a stronger than average one thereafter. Caution needed re extrapolating current PV status as definitely characterising how it will behave all of this winter...

Yes, I do think though looking at the current output that it wont be at least until second half of Dec, i confess though, listening to other more knowledgeable people and with a bit of gut feel it must strengthen at some point and it will probably mean a zonal second half of winter.

EDIT : Control the only genuine flatliner - unfortunately an outlier.

Edited November 15, 2016 by feb1991blizzard

[karyo]

1 minute ago, CreweCold said:

That is my main fear Ian..and the reason I want to exploit this weak PV as soon as we possibly can. It's all good and well saying patience required...but it doesn't always work that way...

Agreed! When you live in a place exposed to Atlantic weather, the more a cold spell is delayed the less likely it is to happen.

Hopefully we will see a cold pattern emerge soon and a wintry December will materialise.

[fergieweather]

7 minutes ago, CreweCold said:

That is my main fear Ian..and the reason I want to exploit this weak PV as soon as we possibly can. It's all good and well saying patience required...but it doesn't always work that way...

Correct, and (as witnessed last year, in Jan if I recall), due suspicion - but not outright discounting - should also focus on GEFS leanings to showing marked zonal reversals/SSW's into extended range unless and until firm, decisive support exists in certain other key stratospheric modelling. 

Edited November 15, 2016 by fergieweather

[feb1991blizzard]

ECM ensembles pretty decent, a good cold clustering with 1 'proper' cold frigid, hazard a guess that its a powerhouse Easterly.

[Cheshire Freeze]

4 minutes ago, fergieweather said:

Correct, and (as witnessed last year, in Jan if I recall), due suspicion - but not discounting - should also focus on GEFS leanings to showing marked zonal reversals/SSW's into extended range unless and until firm, decisive support exists in certain other key stratospheric modelling. 

Aye...

On a slightly related note..I feel you've given us all enough hints as to where you feel we may be headed post this potential disturbed PV spell and I'm guessing that none of the modelling at UKMO towers is hinting at such a reversal (SSW)??

Edited November 15, 2016 by CreweCold

[Hocus Pocus]

9 minutes ago, CreweCold said:

That is my main fear Ian..and the reason I want to exploit this weak PV as soon as we possibly can. It's all good and well saying patience required...but it doesn't always work that way...

Indeed, the law of averages at least dictates that. In the meantime what we don't want to see is some of these promising charts always being stuck at day 10 and never making it into the t-144 range. One thing which does worry me is having the block in the wrong place and we end up with west based NAO. 

I think I need to up my dosage of happy pills 

[fergieweather]

7 minutes ago, CreweCold said:

Aye...

On a slightly related note..I feel you've given us all enough hints as to where you feel we may be headed post this potential disturbed PV spell and I'm guessing that none of the modelling at UKMO towers is hinting at such a reversal (SSW)??

The period by late Nov / early Dec is certainly not without interest, but whether we see technical SSW is another matter. In a way it's by-the-by, because the underpinning signal is conclusively for an exceptionally weakened/disturbed PV into that period and hemispherically, the 300hPa GPH fields really couldn't paint a picture more foretelling of the enhanced blocking potential. 

[marksiwnc]

3 minutes ago, fergieweather said:

The period by late Nov / early Dec is certainly not without interest, but whether we see technical SSW is another matter. In a way it's by-the-by, because the underpinning signal is conclusively for an exceptionally weakened/disturbed PV into that period and hemispherically, the 300hPa GPH fields really couldn't paint a picture more foretelling of the enhanced blocking potential. 

I have a sneaky feeling that Ian has more info that he can't confirm at present but the chances of quite a substantial cold spell happening from 29/30  onwards is quite big. I've said this since end of October..  I think December will get colder through the month but not masses of snow only glancing blows from the Atlantic for south Western areas and Ireland.  anyway let's hope

[fergieweather]

7 minutes ago, marksiwnc said:

I have a sneaky feeling that Ian has more info that he can't confirm at present but the chances of quite a substantial cold spell happening from 29/30  onwards is quite big. I've said this since end of October..  I think December will get colder through the month but not masses of snow only glancing blows from the Atlantic for south Western areas and Ireland.  anyway let's hope

I assure you I'm hiding nothing... no magic bullet is hiding in eg GloSea5. The dice remain quite evidently loaded towards a higher risk of colder weather into December, BUT we're no clearer on the scope of how this may unfold and nothing in the Tues 12z ENS up to 30 Nov necessarily offers the clearest route by then, nor for that matter any guarantee that it will even be particularly cold at that stage. Plenty of days to get through this month and see the route of travel ahead...! :-)

[Mucka]

2 hours ago, CreweCold said:

This is the UK, barring exceptions we are always unlucky 

Also, we have to take one of those bites of the cherry...otherwise we end up with a nearly winter (like we've seen before) and before you know it we're crying into our cornflakes in March! I'm not saying we won't grasp a better opportunity as we move into winter proper...I'm just reminding folk how quick the winter season flies by and completely agree with Nick S where he says if it can go wrong it will as far as UK weather is concerned.

 

 

A bird in the hand is worth two in the bush, gotcha. 

And yeah if it can go wrong it will go wrong etc.

Just saying we will get more bites at the cherry than usual and even the UK gets lucky sometimes. 

[jules216]

Finally got home from my troublesome snowy trip in Tatra Mountains and hereby presenting you a link to an Italian site that describes the Ecmwf interpretation of December,that is some cold! http://www.freddofili.it/14887-dicembre-ultime-proiezioni-ecmwfens-freddissime-gelo-dalla-russia/

[Mucka]

So no morning dramas from the main models so far at 144 UKMO and GFS showing good Atlantic ridges.

But GEM sticking with the much flatter upstream pattern

 

GFS stays quite cold for the North and central parts of UK right out to 23rd/24th when ironically it finally warms up in strong Easterly flow. (at least briefly)

It's pretty close to the 18z except with high further North and better oriented. The lack of cold uppers would be a crying shame really.

After day 10 it produces the usual shortwave spoiler around Southern Greenland which is pretty random at that range and best ignored for now, most importantly it wants keep the Atlantic blocked.

Edited November 16, 2016 by Mucka

[northwestsnow]

Agreed Mucka

Happy to see both GFS/UKMO on a similar page and certainly not the same page as last nights ECM.

I'm not too fussed about FI on Gfs, its all about trends for now, hoping to see some FOG before months end...:D

Edited November 16, 2016 by northwestsnow

[Mucka]

18 minutes ago, northwestsnow said:

Agreed Mucka

Happy to see both GFS/UKMO on a similar page and certainly not the same page as last nights ECM.

I'm not too fussed about FI on Gfs, its all about trends for now, hoping to see some FOG before months end...:D

One thing that is strange though is that GFS seems desperate to find a way to push energy over the block and prevent heights pushing into Greenland, probably why we aren't seeing a true cold signal develop in the ensembles.

After a quick run through 00z set I couldn't find a single true Greenland high throughout the entire run in a single member which is strange given conditions look ripe for one to develop.

Perhaps someone else can elaborate on what that teleconnection/background signal might be.

[The PIT]

Nice too see Saturdays low pressure still there in the GFS. More of a swing in deep FI towards yesterdays ECM solution.

[Mucka]

GFS 00z ensembles, still no real cold signal as yet.

 

[Mucka]

16 minutes ago, The PIT said:

Nice too see Saturdays low pressure still there in the GFS. More of a swing in deep FI towards yesterdays ECM solution.

Sorry but that seems a little misleading. Here are today's GFS and yesterdays ECM comparison.

GFS on left