Model output discussion - heading into 2018

[blizzard81]

Look at that blasted pv fight back though. Totally relentless. 

[Daniel*]

Interesting just like the ECM the GFS 18z sends a low diving se into mainland Europe. May be a bit of a trigger! 

[Allseasons-Si]

18z gfs at day ten and ecm,gfs i like you

Edited December 27, 2017 by Allseasons-si

[nick sussex]

1 minute ago, blizzard81 said:

Look at that blasted pv fight back though. Totally relentless. 

Yes but that’s the lower resolution part of the output and models struggle with energy distribution this far out.

The GFS will always try and take too much energy east or ne.

Overall not a bad trend this evening.

[Man With Beard]

An interesting extended ens tonight with signs of something more blocked to the NE, particularly with the control run which looks ripe for slider lows into a wind source east of south. However, the ECM ensembles have been wondering around over the past two days, from Canadian heights yesterday to Euro heights this morning and now Scandi heights tonight. Still finding it's way after T216 I feel. If I was placing bets I'd say more of what we've been getting this week - westerlies with occasional northerly influence. Like Steve Murr put beautifully earlier on - getting the most winter out of a situation without HLB. (Unless tonight's ECM control is the trend setter :). )

Edited December 27, 2017 by Man With Beard

[bluearmy]

this wedge of heights up to Svalbard, becoming cut off , during week 2 is not surprisingly, also a fairly well supported eps cluster 

[nick sussex]

Time to recharge your batteries coldies looks like we might be on another chasing east/ne saga ! 

 

[Allseasons-Si]

3 minutes ago, bluearmy said:

this wedge of heights up to Svalbard, becoming cut off , during week 2 is not surprisingly, also a fairly well supported eps cluster 

This then helps force the troughs further SE and cold air backing west out of Scandi,not a bad run.

[Allseasons-Si]

2 minutes ago, nick sussex said:

Time to recharge your batteries coldies looks like we might be on another chasing east/ne saga ! 

 

Only another 300+ hours to go then

[doghouse]

Regarding the Infantile Polar Vortex Schtick. Imagine yer football club were in the Chamions league ( appreciate that’s difficult for most of ye ) and facing Messi home and away........”see that Messi he always scores really important goals”.........utterly predictable and idioticly futile complaining about it.

[Nick F]

Despite the Polar Vortex strengthening to almost record levels looking at GEFS 10 hPa U-wind charts, the GFS op on 18z run continues to suggest some amplification still possible over the N Atlantic enough to split the trop PV into lobes over Canada/Greenland and NE Europe, before the Euro trough fills and sinks to allow height rise to the NE. The amplification likely a result of the return of the  poleward -EPO ridge amplifying the flow downstream.

Alternating cold and mild zonality seems certain and also worth noting the strong undulating zonal jet will bring a conveyor of lows and plenty of rain and occasional snow which could start to pose flooding issues over the next week or so, given a lot of rain has fallen since the weekend.

The potential for height rises to the NE still needs plenty more runs to indicate whether this is viable though, so sitting on the fence on this idea, despite the eye candy popping up. Nice to see the GFS show something else other than endless zonality though.

Edited December 27, 2017 by Nick F

[bluearmy]

The only concern on the cold snap end next week being that the op was the warmest run at day 10. Want to see that change on the 00z run.

Edited December 27, 2017 by bluearmy

[feb1991blizzard]

2 minutes ago, bluearmy said:

The only concern on the cold snap end next week being that the op was the warmest run at day 10. Want to see that change on the 00z run.

Agreed but I would have thought you would be the last person to flag this up until at the very very least 12z tomorrow if it was still showing.  I know your views on FI op runs!!

[Allseasons-Si]

I am liking the trend to colder temps on the ens from the 6th though BA

de-built temps,dewpoints and wind direction,wind direction from the 6th showing more members going for an easterly there if i am reading that right.

London in house 850's and av temps not to be sniffed at either

Edited December 27, 2017 by Allseasons-si

[Allseasons-Si]

We can only dream

p16

there is a few that show height rises to the NE.

[Bruegelian]

Isn't it the case though, that we have had some very potent cold spells when the polar vortex was strong/fairly strong, e.g. Jan 87 and Feb 91? Apologies if this is incorrect.

Edit: Chart for 1 Feb 1991:

I know that generally a strong polar vortex is not good for cold here, but I think there are few cast-iron rules with the weather. 

 

Edited December 28, 2017 by Bruegelian
adding chart

[JBMWeatherForever]

This colder trend now being shown from the 6 Jan, in line with SM's zonal wind dip, seems quite promising for some longer lasting cold from the NE or E. We also seem to be doing quite well out of the current set up with another promising fall of snow now likely for another part of the country on Friday, namely northern England and southern Scotland. I'm watching this very closely, any slight changes to the fax charts could make all the difference between a major snow event or just a very temporary slush fest. Lots of interest in both the short term and longer term now!

Edited December 28, 2017 by JBMWeatherForever

[Allseasons-Si]

Looking to see if there will be height rises to our NE i have picked out the 18z ens from Oslo,Scandinavia and there is a def trend there

[geordiekev]

1 hour ago, Allseasons-si said:

Looking to see if there will be height rises to our NE i have picked out the 18z ens from Oslo,Scandinavia and there is a def trend there

My worry is, even though I've only been following the forum and charts for only 10 years is that greeny/Atlantic highs more often have run to 0z than Scandis. The only 2 Scandis that occurred, if I recall correctly, didn't deliver as were slack,dry and cold and the after effects of warming the Arctic unfortunately didn't promote snow to the UK and the rest of the winter was a write off due to the warming above Scandinavia, although the spring and following summer (till mid July 2016 in the NE) remained in a cold easterly.

Much prefer a Northerly as any diversions from North will still deliver to many as opposed to the rarity of a Scandi.

Edited December 28, 2017 by geordiekev

[knocker]

An icy start with quite a severe frost in many places this morning with a touch of fog added. It will then be bright, but cold, more or less everywhere albeit with some wintry showers in Scotland and perhaps the west coast. Later in the day cloud and rain will encroach over Cornwall.

Apart from Cornwall tonight will be clear with once again a severe frost in many places but by now there is heavier rain in the south west which will move northeast during the day but will fall as snow along the northern edge in Wales, the Midlands and the north and southern Scotland as it hits the cold air. Mainly on the high ground bur certainly at low levels as well.

The weekend continues with the unsettled theme as more frontal; systems traverse the country bringing patchy rain but probably snow in Scotland accompanied by some strong winds in the north. So by 12 Sunday we have the main deep depression south of Iceland with the subsidiary 972mb in the north North Sea and the UK in a brisk westerly. But by 1800 on Monday the main low has slipped across Scotland and a wave has formed west of Ireland and has tracked quickly across southern England bringing rain to Wales and the south. Equally quickly it carries on tracking east into Denmark briefly initiating a light northerly over the UK by 1200 Tuesday as  the Azores high pressure attempts to ridge north east.

In fact it does succeed briefly and a fairly quiet 24 hours ensues but by Wednesday 1800 we arrive at an analysis that epitomizes the current set up. A major upper trough to the north west and the colder Pm airmass with the warmer air to the south west with a strong thermal gradient marking the boundary between the two. On the surface this translates to a deep depression 961mb north west of Ireland (explosive cyclogenesis) with the associated warm front and rain across western parts of the UK whilst the cold front trails from Ireland away to the south west.

The warm front duly crosses the UK with perhaps more snow in Scotland and briefly introduces much warmer air but by 1800 on Thursday the cold front is through and a much colder Pm airmass is over the UK with quite possibly gales in the north and  wintry showers in Scotland, N. Ireland and the west coast.

Over the next 24 hours the main low drifts south east adjacent to Scotland which would if it verified, which of course it will not be. would bring blizzards and severe gales to Scotland. All the same it does illustrate that in this sort of set up some severe weather can quite easily occur and it pays to be vigilant.

The GEFS mean anomalies this morning still maintaining the unsettled theme bur also the ridging from eastern Europe into the eastern Arctic and thus perhaps a split flow in the eastern Atlantic.

Edited December 28, 2017 by knocker

[West is Best]

Oh ECM oh ECM, you darling beauty of a model you. Were I able, I would pad across the room and, with your permission, place a demur kiss on your cheek, then take you by the hand and dance together. How you will lift the mood of those naysayers who have assured the entire universe that the Atlantic treadmill will forever run until springtime washes away the last hopes of cold lovers.

It may never happen but this is ... this is ... this is ... to die for:

T192:

T216:

T240 Chart of the Winter:

Edited December 28, 2017 by West is Best

[Ali1977]

2 minutes ago, West is Best said:

Oh ECM oh ECM, you darling beauty of a model you. Were I able, I would pad across the room and, with your permission, place a demur kiss on your cheek, then take you by the hand and dance together. How you will lift the mood of those naysayers who have assured the entire universe that the Atlantic treadmill will forever run until springtime washes away the last hopes of cold lovers.

It may never happen but this is ... this is ... this is ... to die for:

T192:

T216:

T240 Chart of the Winter:

That's a very weak Scandy high, I may be wrong but that looks like it's just get bowled over by a strong Atlantic - it's a better chart than of late though, and could always improve from this run

[West is Best]

10 minutes ago, Ali1977 said:

I may be wrong but that looks like it's just get bowled over by a strong Atlantic

That's Alistair Cook yesterday at the start of his innings

Okay, I got a little excited but it's the evolution I love. We have had tantalising glimpses over the past week, but this is the first time one of the major models has lifted up its skirt to reveal the full thigh.

 

Edited December 28, 2017 by West is Best

[knocker]

Without analyzing in detail the ecm (I may have the correct run this morning) also going for some very unsettled weather next week with periods of rain, perhaps snow in the north and Scotland, with very strong winds, perhaps severe gales at times. Just some spot charts

[tight isobar]

43 minutes ago, West is Best said:

Oh ECM oh ECM, you darling beauty of a model you. Were I able, I would pad across the room and, with your permission, place a demur kiss on your cheek, then take you by the hand and dance together. How you will lift the mood of those naysayers who have assured the entire universe that the Atlantic treadmill will forever run until springtime washes away the last hopes of cold lovers.

It may never happen but this is ... this is ... this is ... to die for:

T192:

T216:

T240 Chart of the Winter:

A very elaborate 'heart felt post'..?

Yes' certainly some very decent op-runs coming in now.

Trawling through gfs ens are also offering up some promise into the new year...with northerly incursions again flagging-in part with some quite potent pm flows.

Snapshoting' the 240-ec00z op, its feasible the mlb-AT blocking (could) be evoling to some linking' with scandiavian height rises...certainly somthing to be eyeing in coming days.

But-even within/before that parameter...there remains potential for some active/notable wintry snaps/with snowfall, on a; nowcasting situ as 24/48 hrs northerly-or pm air gets in to the uk...

Certainly an, evolving sit up and look basis now.

Edit;..it would also be naive not to mention some potentialy" very stormy active weather in between also...

Certainly benign, does'nt come to mind going forwards...lots of interesting weather in the mix!

 

 

Edited December 28, 2017 by tight isobar