Model Output Discussions 12z 01/09/2016

[Matthew.]

The ECM firming up on the HP for Thurs-saturday next week. Saturday a scuttle change begins taking place and cold upper air encroaches the north of Scotland:

[Ali1977]

Great day 10 onecm, plenty of potential for quite a sustained period of blocking.

[Frosty.]

Well the charts get better for coldies on the Ecm 12z with an increasingly cold spell as arctic air surges south across the uk with 528 dam thicknesses and set up for reloads beyond T+240. Hopefully a taste of things to come during the winter.. there would be snow for some and frosts for all.

Edited October 22, 2016 by Frosty.

[Matthew.]

6 minutes ago, Ali1977 said:

Great day 10 onecm, plenty of potential for quite a sustained period of blocking.

Yes!:

[knocker]

An interesting ecm run. The HP duly ridges NE at the beginning of the week and by Wednesday is centred to the south of the UK.  But it has little development north as there are couple of upper lows, one N Canada and the other Iceland, forming a general area of low pressure to the NW and north compressing the high pressure with a subsequent very strong westerly airflow. From here the trough to the north tracks east then SE whilst the HP ridges to the NW to combine with pressure rising around Greenland  Thus we have a classic Omega block mid Atlantic with the upper trough running SE over the UK dragging down some cold air.

Edited October 22, 2016 by knocker

[cheshire snow]

Some great potential for our first cold snap/spell at the beginning of November.I will be a lot happier when these charts get into the reliable

Time frame.

Let the chase begin

C.S

[knocker]

12 minutes ago, cheshire snow said:

Some great potential for our first cold snap/spell at the beginning of November.I will be a lot happier when these charts get into the reliable

Time frame.

Let the chase begin

C.S

It doesn't in fact need that much tweaking to get a different outcome. If the amplification is less intense then maybe the ridging to the NW is as well leaving higher pressure in situ over the UK. This in turn would have the affect pushing the track of the upper trough slightly more to the SE and thus cutting off the cold plunge and leaving the UK in a cool NW airstream. Just saying.

[legritter]

Great forum ,very interesting charts tonight ,current fax charts would cause a stir if later into the winter . 

We are looking at nothing disturbed over the coming week going by current data ,then we have the big carrot in the further outlook charts ,if it comes off  and we can tap into some low temp ,and IF synoptics allow ,and it would need a block in place for a while But it's happened before so let's see what the charts look like in a weeks time ,interesting times ahead ,but watch out gang the charts aren't set in stone , cheers .

[Cheshire Freeze]

4 minutes ago, knocker said:

It doesn't in fact need that much tweaking to get a different outcome. If the amplification is less intense then maybe the ridging to the NW is as well leaving higher pressure in situ over the UK. This in turn would have the affect pushing the track of the upper trough slightly more to the SE and thus cutting off the cold plunge and leaving the UK in a cool NW airstream. Just saying.

You could say that about just about any synoptic situation shown in the NWP. A 'tweak' could change a SWly into a Wly, a SE'y into an Ely and so forth. 

[knocker]

15 minutes ago, CreweCold said:

You could say that about just about any synoptic situation shown in the NWP. A 'tweak' could change a SWly into a Wly, a SE'y into an Ely and so forth. 

Maybe you could but I was trying to add a constructive comment that would suggest a possible different track for the upper trough and one that would follow previous anomaly suggestions. I'm sorry you thought it rather frivolous and nonsensical. 

Edited October 22, 2016 by ajpoolshark
removed provocative comment

[cheshire snow]

15 minutes ago, knocker said:

It doesn't in fact need that much tweaking to get a different outcome. If the amplification is less intense then maybe the ridging to the NW is as well leaving higher pressure in situ over the UK. This in turn would have the affect pushing the track of the upper trough slightly more to the SE and thus cutting off the cold plunge and leaving the UK in a cool NW airstream. Just saying.

 Hi Knocker

 I quite agree with you hense my main words in my post were POTENTIAL and RELIABLE

 Cheers

 C.S

 

[A.J]

12 minutes ago, CreweCold said:

You could say that about just about any synoptic situation shown in the NWP. A 'tweak' could change a SWly into a Wly, a SE'y into an Ely and so forth. 

Knocker is merely musing on one possible outcome based on current model data, therefore I feel your post is unnecessary and it is not really relevant to this thread (i.e current model output and possible outcomes)

and having read the past couple pages, I'm to not keen on the underlaying current seemingly prevailing between a few members....Let's keep this discussion friendly please, and strictly on topic.....cheers

Edited October 22, 2016 by ajpoolshark

[SMU]

2 hours ago, bryan629 said:

Hi Steve 

Heres todays updated AO index... absolutely better clustering .. just a question of how low will it go !! 

Yes

a steady overall drop around 1 point...

[SLEETY]

So still no sign of the Atlantic train yet ,as we head towards nov ,its really quite fascinating as Winter approaches how long this can continue..The models agree that a cold plunge from the North could be the form horse after a week or so and the glosea5 and ec,46 ,seem confident in that scenario too,what happens after that is the interesting thing,can this carry on into winter ,or will the Atlantic finally wake up,?

[Frosty.]

This looks really good for coldies, I've been following the mean charts closely and tonight's Ecm 12z ens mean is a significant upgrade on the 00z in terms of a potential arctic shot beyond the anticyclonic spell.

[Thundery wintry showers]

There is fairly strong support for cold northerlies into early November, though Knocker is right about the caveats, especially at this time range.  Those expecting widespread snow from the northerly, though it is not unheard of at this time of year, are likely to be disappointed, because the Arctic will be anomalously warm for early November, partly as a consequence of the very amplified weather pattern, and unlike on 26/27 October 2012 (when, remarkably, many north-eastern districts saw snow in October despite the abnormal warmth around the Barents Sea that year), we are unlikely to tap into a localised cold pool to the east of Greenland.

NOAA's 8-14 day outlook strongly highlights the impending north-western blocking:

http://www.cpc.ncep.noaa.gov/products/predictions/814day/500mb.php

With the MJO likely to hang around phase 7-8, a transition to less settled and rather cool weather is likely into early November with frequent north-westerly and northerly winds, perhaps cold enough for some wintry precipitation in the north if the pattern keeps up for long enough into the first half of November, but a less cold west to north-westerly type could also develop.  However, at present things do look remarkably different to how they did this time last year.

Edited October 22, 2016 by Thundery wintry showers

[bluearmy]

Extended eps consistent in developing sceuro low anomaly in conjunction with the high anomaly to our wnw through week 2 =  cold for nw Europe 

Apparently glosea picked out this early November HLB so encouraging to see it coming into view

 

 

[knocker]

The ecm 6-10 and day 10 indicates the strengthening of the Greenland HP and portending the continual veering of the wind to the NW quadrant and temps cooling below average.

Edited October 22, 2016 by knocker

[Mucka]

48 minutes ago, bluearmy said:

Extended eps consistent in developing sceuro low anomaly in conjunction with the high anomaly to our wnw through week 2 =  cold for nw Europe 

Apparently glosea picked out this early November HLB so encouraging to see it coming into view

 

 

As have GEFS and EC32 to be fair. I think it was nearly a week ago when I first commented on it within GFS ensemble FI so all models have done pretty well so far.

 

Edited October 22, 2016 by Mucka

[fergieweather]

46 minutes ago, bluearmy said:

Extended eps consistent in developing sceuro low anomaly in conjunction with the high anomaly to our wnw through week 2 =  cold for nw Europe 

Apparently glosea picked out this early November HLB so encouraging to see it coming into view

 

 

Yes, GloSea5 performance has been good thus far (including stratospheric modelling for this period from runs even output back in mid-Sept), but ECMWF Monthly model was equally very keen on picking-out the potential (as now reflected by operational models, albeit devil will be in detail) for +ve MSLP building to NW and resultant cooler/colder flow into early Nov (refer to my earlier posts re this expectation).

How much this emergent pattern will then sustain through November is quite another matter, but for now at least, there remains scant sign of 'mild 'n wild' Atlantic-borne weather within the latest (12z) ECMWF ensembles across the 15d period. With the GloSea prognosis equally considered, such a pattern still remains less likely than average during the early to 1st half of next month. 

[Mucka]

Going down run by run? (Northern England)

Edited October 22, 2016 by Mucka

[knocker]

Today

Eastern Scotland still under the influence of the North Sea low and the NE wind so cool with showers whilst the west of Scotland and N. Ireland should be dry and sunny. England and Wales also dry, perhaps less sunny, but rain spreading to the south west this evening moving ENE and petering out as it goes.

On to the GFS.

As the low to the south west drifts south it is quickly replaced by ridging from the Azores HP connecting to the HP to the NE. This leads to a high cell to the south of the country by Thursday 12z with a quite intense trough to the NW in the vicinity of Iceland. Ergo quite a tight gradient with a 130kt jet running just north of Scotland and and any systems running ENE confined to affecting the Latter

As the week progresses the trough tracks east, pressure rises over Greenland and the European  high pressure retrogresses NW to connect with the latter leaving this situation by 0600z Sunday.

The pattern then amplifies with pressure building to the west and the trough slipping south east to be east of the Baltic by Tuesday. All of this has the potential to drag some quite cold air down from the north at the beginning of next week with snow a distinct possibility on high ground. Of course how the detail of this pans out will be resolved in the next few days.

Just a quick glimpse on how the GFS proceeds. It actually rotates the upper pattern clockwise which results in the trough moving SW

Edited October 23, 2016 by knocker

[Polar Maritime]

The GFS this morning shows a long drawn Northerly by next Thursday, With -5/-6/-7 850's covering a large swathe of the UK giving the potential for the 1st snowfalls for some..

 

Edited October 23, 2016 by Polar Maritime

[knocker]

And from the GEFS mean anomaly with everything just a tad further east

[northwestsnow]

Another essentially very dry GFS 0z this morning, certainly the signal remains for a pretty strong Greenland High as we move into November.

Perhaps a WQBO doesn't preclude strong heights at Higher latitudes afterall