Winter Model Discussion 18Z 13/1/13 onwards.

[SLEETY]

Why because its not showing what u want?

no because it doesnt look right and its at odds with the rock solld ukmo,actually!

[swfc]

Very odd looking chart between 96- 120hrs on ecm???

Edited January 14, 2013 by swfc

[Harsh Climate]

The way I see things shaping up, is the atlantic will break through sometime this weekend. We have seen run after run of this happening on the GFS and ECM models and now the UKMO hints at this (albeit very snowy breackdown on the UKMO.) I just can't see the block withstanding this upcoming onslaught especially as we look like having a fully reinvigorated jet exiting the eastern sea board into the north atlantic, as well as that we have a huge slab of the polar vortex looking like crossing the atlantic, about to have a serious go at our block . Just think there's too much pressure against our block to have any chance of winning the battle.

.

However the angle of attack from this upcoming atlantic onslaught will be crucial to what sort of breakdown we shall recieve! The UKMO gives us snowmaggedon with widespread falls of over 6 inches from southern england ~ northern england. With the area just to the north of this frontal snowfall getting battered with heavy convective snow showers been blown in from the north sea. If the jet can attack from a more northerly quarter like NNW or NW as opposed to straight west, that should allow the advancing fronts/shortwaves to be squeezed under our block and keep us in this cold continental airmass as we maintain an easterly feed.

Looking at future precipitation charts regarding this, one thing to look out for when the precipitation finally makes it through our block, is we want the precipitation to reach the southwest and southern england first and spread northwards to other areas, this would be the perfect angle of attack!

Got to say though the the UKMO 144h is very similar to Feb1991

UKMO

1991

So all in all I think there is a real chance we could be looking at a major snowfall this weekend with the south west of england taking the brunt (about time too) and even if it does get milder after next weekend, I think it will be short lived as early indications suggest this may just be the start of our winter ; )

Edited January 14, 2013 by Harsh Climate

[BLAST FROM THE PAST]

I would hardly call this "progressive":

Agreed, it'll actually be a tad less progressive with heights more broad to our NE

BFTP

[Continental Climate]

NICE!!!! http://www.meteociel.fr/modeles/ecmwf/runs/2013011412/ECH1-120.GIF?14-0!!! The atlantic basically told to bugger off

[karlos1983]

Very odd looking chart at 120hrs on ecm???

Very odd from 72 - 96 I can just get my head around, but 96 -120? someone please help?

+96

+120

[ChartViewer]

Meanwhile at a very different pace...snail like...the Big gun trundles out

CMA 24

[nick sussex]

The ECM keeps the main PV further west than the GFS with a big snow event from 96hrs to 120hrs, it broadly backs the UKMO with the position of the positive anomalies to the north.

Some differences with detail regarding the UKMO but compare where the GFS has the PV at 120hrs and where it is on the ECM.

[Continental Climate]

Meanwhile at a very different pace...snail like...the Big gun trundles out

CMA 24

Your devotion to the cma is admirable although it usually produces decent eye candy

[Weathizard]

Looking at the models at T96-120, there is a general agreement of some sort of heights to our north but a complete lack of agreement with regards to the Atlantic and how much/if any energy gets sent underneath the block. If you look at T96 its almost a complete split really with regards to how the 3 big models handle the Atlantic push.

[bluearmy]

looking at ecm, there should be some eye candy on the FAXES later. the ecm looks slack but check the cartes france view to see the isobars and where the circulation is

[Jason H]

That block is immense. It just stops the Atlantic in its tracks at T120

[Harsh Climate]

So that means it's going to happen then? - don't forget it was just yesterday that Exeter 'watered' down their FAX charts in correlation to some of the other models.

Since when did I say it's going to happen, did your crystal ball tell you that??

[Weathizard]

Atlantic breaks through at 144

The evolution off this pattern is still up in the air however I think with GFS and ECM both going for the breakdown at day 6 its starting to become clearer there could be a brief period of zonality, its not nailed yet but its been a consistent feature of both GFS and ECM runs in recent days. Could be frontal snowfall before then though as we are attacked by the Atlantic.

Edited January 14, 2013 by Weathizard

[nick sussex]

More snow at 144hrs on the ECM, surface flow would be se ahead of the precip.

Much better shape to the troughing than the GFS.

[Mucka]

It is easy to get lost in the detail of each run but when there is no consensus run to run or across models it is probably better to take a step back and look at the big picture and see if there is a general trend. I would suggest there is and if you check each model against its own output over the last couple of days you will seee the trens has been for high pressure to move NW rather collapse SE.

If this ECM run is not on the mild side on the London 2m ensembles from 144 I will be surprised and a little more concerned about the amount of undercut we can expect.

[Continental Climate]

Atlantic breaks through at 144

It does but i personally think the low will be a lot further south than is being shown, all it needs is our high to the north to be a little more robust and everything gets forced south, im quite happy with todays runs actually

[Cloud 10]

Big changes on tonight's ECM chart for Saturday compared with yesterday's run,quite laughable

really,and much more in line with the UKMO.

yesterday.. today..

[bluearmy]

More snow at 144hrs on the ECM, surface flow would be se ahead of the precip.

Much better shape to the troughing than the GFS.

the occlusion at day 6 is in the same place as at day 4. at day 6, however, there is a chunk of discarded vortex behind the trough which should send it further north. but what about the shortwave running off the jet to the west - could extend the trough se into france??

[cooling climate]

GFS still playing catch up I see although it took the ECM operational long

enough. Can not see an end to this cold spell myself not until after the

weekend at least.

Still waiting for the SSW to really show its hand (tanking AO) but nothing

as of yet.

ECM t144 better heights to the n/ne and energy further s/sw than the 0z at

same time frame. Improving all the time.

[BLAST FROM THE PAST]

What we are seeing on ECM is a block forming to our north with the Atlantic getting through and underneath but basically through the UK and not south enough ...yet. However, it is gradually coming thorugh ever so further south and getting ever so slightly delayed by the ECM. Another small footstep towards the UKMO

BFTP

Edited January 14, 2013 by BLAST FROM THE PAST

[Harsh Climate]

Ecm does offer us some snow 96-120h though

Most likely wales/south west england and parts of the west.

[pages]

Very odd from 72 - 96 I can just get my head around, but 96 -120? someone please help?

+96

+120

A couple of the gfs ensembles did this and they stayed cold the whole run, ended with Greenland high and the vortex coming at us from the north east

[R.P. McMurphy]

Quality ECM and GFS tonight. Atlantic not even getting a sniff at heading back to the UK. Sustained cold and from what I can see a hefty snow fest for NW, Wales, West Country and the SW come this Friday into the weekend. Couldn't ask for more to be honest. Absolute no mild weather in sight.

[Methuselah]

What we are seeing is a block forming to our north with the Atlantic getting through and underneath but basically through the UK. However, it is gradually coming thorugh ever so further south and getting ever so slightly delayed by the ECM. Another small footstep towards the UKMO

BFTP

I just hope that the UKMO are on-the-money, Fred...But I'm not going to be making any prognostications, as I simply do not know!