The hunt for cold - Model discussion (late November)

[northwestsnow]

GFS wanting to build a strong PV on the 00z run..

No thanks GFS.

Hints of a warming in the strat at the same time though

Edited November 23, 2018 by northwestsnow

[Rocheydub]

ECM 00z run also has us under SW’lys from the 27th of this month until the end of the run, with a strong portion of PV settling in over Greenland. 

 

Straw clutching time, although it’s looking like it will get pushed away, there are still heights hanging around (albeit eastern) Scandinavia. Strong Siberian ++ heights too. 

 

Not looking great at all in the medium term from a coldie perspective!

[mb018538]

Not looking particularly good this morning as others have said - looks like an actual zonal period may set in with the attendant wind rain and mildness.

Met update is still very bullish about blocked conditions returning as we head through Decemeber. You don't get that feeling this morning, but they must know something we don't!

[Duane S.]

Medium term now strong odds on for a milder very unsettled spell. Very difficult to envisage this now not occuring. East coast US gain, our pain...

Yesterday I pointed out the only realistic conceivable way I could see of avoiding this - getting enough vertical WAA though the UK / just east of the Meridian at around D5. This could allow the block, just, to prevail over the Atlantic trough. Even then there would still have to be a short spell of SWerlies (that is nailed on) but only a few days as opposed to what could be 7 - 10 days+

It was only member 4 on the 12z and it is only really member 7 on the 00z. So less than 5%.

Leads to...

Leads to...

 

[carinthian]

UKMO pick of the models out to 144t for prolonging the colder wind flow for a while longer. The latest run not as progressive as the last one.Hint of a slower transfer for veer towards a milder wind flow to take place around mid -week. Until then will start to feel cold especially as the wind picks early next week ( Chart below 850mb temps Wed morning ). Longer term, I still have doubts as to the movement and speed of progression of the low coming the way of the British Isles. Will get an update with thoughts from over here later this morning.

C

Edited November 23, 2018 by carinthian

[northwestsnow]

Well for sure we are indeed looking at an unsettled phase, i might be clutching at the old straws a little but i feel day by day 10 on the EC the jet is about to start digging into Europe and allowing for a more WNW direction of attack.

[Tim Bland]

I’ll leave this here as an antidote for coldies who have just seen the models ...

 

[Met4Cast]

ECM looking pretty damn zonal too

[SLEETY]

has the cfs ever been correct at that time scale.Please just this once.

Meto still insisting cold blocked weather will return IF the Atlantic breaks out.

Maybe the models are STILL too progressive ,it’s still not in the reliable time frame this low pressure system.

[northwestsnow]

EC mean suggests to me quite a few members are showing some height rises in the scandy locale and a slight shift south of the jet -

Thats my take on it anyway..

[northwestsnow]

9 minutes ago, Daniel Smith said:

ECM looking pretty damn zonal too

It is, but i have a feeling this unsettled blip will be just that, a blip.

I suspect as i have just posted, a number of EC ens will be showing height rises over scandy (not a block ), but enough to see some energy digging into Europe.

Then again iv'e just finished a 60 hour week on night shift  so could be going delirious!! Perhaps Blue will be on later to offer some thoughts if this is feasible ..

 

Edited November 23, 2018 by northwestsnow

[Seasonality]

Interesting thoughts from some very knowledgable posters regarding the fact that even at short range the interaction of the low and the jet stream may not be correctly modelled. I wouldn't be surprised if the currently predicted progression of the low has been overdone. Will be interesting to see how the next few days pan out.

[Seasonality]

2 minutes ago, northwestsnow said:

It is, but i have a feeling this unsettled blip will be just that, a blip.

I suspect as i have just posted, a number of EC ens will be showing height rises over scandy (not a block ), but enough to see some energy digging into Europe.

 

Agreed, as per my post above I think that there'll be some interesting twists and turns in the next few days!

[Decemberof2010]

Well I’m still on the hunt for cold and in the GEFS this morning I’ve found some nice looking charts. And the best thing is they’re only at 384hrs out!!!!!!

 

And this is only at 348hrs!!!!

What could possibly go wrong?

 

Edited November 23, 2018 by Decemberof2010

[LightningLover]

 

24 minutes ago, Tim Bland said:

I’ll leave this here as an antidote for coldies who have just seen the models ...

 

Silly question, but how do you access those time frames on Meteociel? Cheers

[JeffC]

20 minutes ago, SLEETY said:

has the cfs ever been correct at that time scale.Please just this once.

Meto still insisting cold blocked weather will return IF the Atlantic breaks out.

Maybe the models are STILL too progressive ,it’s still not in the reliable time frame this low pressure system.

I refer back to my comment of yesterday morning. It wouldn't be too much of a stretch to get a situation like 2009, with severe flooding switching to cold with frost and snow within a couple of weeks. 

So long as there's no repeat of the flooding experienced by Cumbria then that would be fine by me. 

[snowangel32]

Even my optimism has been dented this morning as once again we fall on the wrong side of things. South westerlies for a time is bad enough. But the real kicker is seeing the PV oranised and strong again and returning to Greenland and setting up shop. Be intresting to see what the MET have that gives them high confidence of blocking in December. Because at present thanks to our Snow charmed American friends the atlantic is fired up and looking stormy. Maybe a SSW can be the hero. Hard not to feel negative on current output

[Tim Bland]

19 minutes ago, LightningLover said:

 

Silly question, but how do you access those time frames on Meteociel? Cheers

Select ‘CFS Daily’ from the list of models on the left http://www.meteociel.fr/modeles/cfse_cartes.php?ech=894&mode=0&carte=0&run=10

[mulzy]

32 minutes ago, snowangel32 said:

Even my optimism has been dented this morning as once again we fall on the wrong side of things. South westerlies for a time is bad enough. But the real kicker is seeing the PV oranised and strong again and returning to Greenland and setting up shop. Be intresting to see what the MET have that gives them high confidence of blocking in December. Because at present thanks to our Snow charmed American friends the atlantic is fired up and looking stormy. Maybe a SSW can be the hero. Hard not to feel negative on current output

Medium-term charts like this morning's Canadian ensembles gives hope I feel...

[bluearmy]

Assuming now that the solution will play out as agreed across the models whereby the Atlantic piles through .....ukmo at day 5 prompted a second glance but the next feature rushing ne in the base of the trough invigorated the system and any idea of a late dive of disruption fails .......

how mobile and for how long ??.

what has caught my eye over the past few runs (ignoring the building gefs mean theme of mid Atlantic ridge late week 2 - note lots of spread but clear predisposition to amplification) is the polar field evolution. The trop vortex is split ..... the rebuild of the Canadian vortex probably a big factor re the renewed Atlantic mobility as some v low heights are transferred back from Asia across to nw Canada. Week 2 sees the Canadian vortex establishing nnw of Hudson’s around Ellesmere Island and the Asian sector transfer east to  ne  Siberia - this leaves a big space for heights to build around Svalbard and north of scandi in general ...... I would expect the retrogressive theme to become more obvious in the modelling as week two progresses. Atlantic retaining a fair amount of mobility at the same time, does that mean the southern arm hits a developing block and rebuilds a scandi ridge or does it run through in our vicinity keeping us unsettled  ..maybe a slow sinking. I suspect the behaviour of the Azores ridge will dictate what transpires for our part of nw Europe. 

[Summer Sun]

UKMO + extended is very different to ECM in the way they handle the low next week

Edited November 23, 2018 by Summer Sun

[Stu_London]

Although most of the models have some sort of tropical maritime solution in the medium term, looking at the overall Northern Hemisphere profile we are nowhere near so many November's I have observed with a pattern established that can often ruin the first half of winter for cold prospects.

It would be no surprise to me if another potential cold spell comes into view as early as the end of next week.

 

[booferking]

A few days ago we were wondering if the block would hold today we are wondering if we will get hit with hurricane force winds

Edited November 23, 2018 by booferking

[Newberryone]

7 minutes ago, booferking said:

A few days ago we we are wondering if the block would hold today we are wondering if we will get hit with hurricane force winds

Perhaps short term pain for long term gain, who knows, but what does look a dead cert now and which is often the case in these type of weather setups is that Ireland looks like bearing the brunt of  this upcoming turbulent Atlantic spell with the potential for large volumes of rain driven on by a moisture laden south westerly airflow. Met office here this morning flagging a wet and windy spell from Tuesday onwards...

[stodge]

Morning all

Without wanting to sugar coat it too much we are looking at 7-10 days of Atlantic-dominated weather from the middle of next week. We shouldn't be surprised or assume it's the end of winter or anything like that, We often get a milder spell at the beginning of December so this is just normal pattern shifting and changing.

As to what happens before, we'll start seeing some tantalising offerings in the very far reaches of GFS FI before long - my money (and very nice money it is too) is on a pressure rise from the south and mid latitude blocking in the vicinity of the British Isles so not brilliant for fans of snow but fans of cold and especially frost and fog might get a decent spell under a classic winter inversion.

The PV profile is very different to some more recent winters and that has to be of interest though my concern as always with those who want everything to happen in Greenland is the risk of the west based negative NAO which killed the 2010-11 winter at New Year.

For now, the Atlantic will do its thing until it stops doing it and then we can see if we can get anything out of the next amplification.