Model output discussion 8th Feb - Cold for now, but then what?

[Singularity]

Classic model-troubling setup mid-next week with a wedge of higher heights trying to establish near N. UK and a negatively tilted trough in the mid-Atlantic. That trough should disrupt and feed a low across to the Scandi trough - but currently we have ECM going crazy with extra disturbances and GFS really powering up a low as it moves through the Azores - both ways to trash what would otherwise be a setup of some interest for those up north in terms of snow potential. 

Typical stance in these situations is to expect the progress of Atlantic troughs to be well overdone at this range - but to also acknowledge that a change in the background forcing could remove the wedge of higher heights and render this expectation invalid anyway! Such is the nature of trying to get a handle on the chaotic system that is the Earth's atmosphere.

[Frosty.]

I'm jealous! 30cm of lovely snow on hills of central and southern Scotland!!

Edited February 23, 2017 by Frosty.

[cheshire snow]

GFS06z showing wintry PPN in many areas on Monday.

C.S. 

[Ali1977]

1 minute ago, cheshire snow said:

GFS06z showing wintry PPN in many areas on Monday.

C.S. 

Yes next week is actually starting to look pretty wintry, it has potential to be one of the best week of the winter for snow showers , but not that cold so not much lying snow away from high ground I doubt.

[Summer Sun]

30 minutes ago, Ali1977 said:

Yes next week is actually starting to look pretty wintry, it has potential to be one of the best week of the winter for snow showers , but not that cold so not much lying snow away from high ground I doubt.

 

 

Aye

Today's snow will likely melt fairly quickly once the rain and double-figure temps arrives this weekend

Edited February 23, 2017 by Summer Sun

[Frosty.]

1 minute ago, Summer Sun said:

Aye

Today's snow will likely melt fairly quickly once the rain and double-figure temps arrives this weekend

And then it turns colder next week..Nice :- )

[Singularity]

  

It's really saying something when you have a cut-off upper high over Greenland and GFS still manages to move most of the UK back onto the milder side of the polar front.

Need to keep an eye on Greenland in case the surface pressure response trends stronger. At the moment it's only enough to shift the jet south to run across the UK rather than down into Europe. In this way it turns from friend to foe; were it not cut-off, it would likely drift into Scandinavia and support a blocking high there which could at least have fended off the Atlantic wind and rain.

As it is, GFS fancies a go at Doris II: Storming the South, or what the Met Office would less entertainingly name 'Ewan'.

One of these days a storm like this will actually take such a path. I've seen quite a few red herrings of this nature from GFS over the past few years.

Edited February 23, 2017 by Singularity

[Summer Sun]

1 minute ago, Frosty. said:

And then it turns colder next week..Nice :- )

Yep especially so for Scotland but even large parts of England and Wales struggle to make it into double figures

[mb018538]

Well to me wintry showers over higher ground isn't anything to really get excited about! It's high ground. It snows there every winter!

Temps just look chilly up north, and close to average in the south. Bah humbug!  

As for the 6z GFS, less said the better. Unsettled throughout.

[Chris.]

Glencoe did alright from Doris at resort level (600m)  - around 20cm estimated.

 

]   Thanks to them for the picture.

[SMU]

Afternoon All

Ukmo says no to the toppler !

[Paul White.]

10 minutes ago, Steve Murr said:

Afternoon All

Ukmo says no to the toppler !

Hi steve. 

Does that mean that the ukmo is saying yes to to a shallow Greenland/iceland high and a north easterly setting in over the uk bringing colder temperatures ?

 

Cheers 

 

Paul

Edited February 23, 2017 by Paul White.

[Eugene]

10 minutes ago, Steve Murr said:

Afternoon All

Ukmo says no to the toppler !

 

Could you please expand on what you mean by that Steve?

[karyo]

13 minutes ago, Steve Murr said:

Afternoon All

Ukmo says no to the toppler !

It looks better/colder than the GFS for sure.

[SMU]

Most of the models have been pushing the atlantic through that shallow high- UKMO 12z now seeing more undercutting - probably the coldest scenario although not 'very' cold-

however could still develop colder...

[Snowyowl9]

7 hours ago, Frosty. said:

I'm jealous! 30cm of lovely snow on hills of central and southern Scotland!!

 

 

 

 

Reality check it turned out to be a damp squib,I know somebody who lives there.

[Daniel*]

UKMO does look pretty cold. Return of widespread frosts chance of wintry PPN (snow) falling overnight in the south not cold enough during daytime I suspect, what develops thereafter could be more interesting. It would have generated much more discussion, if it was not this time of year oh well less casualties.  

[Eugene]

GEM 12Z builds high pressure over scandinavia.   

[Norrance]

1 hour ago, Snowyowl9 said:

Reality check it turned out to be a damp squib,I know somebody who lives there.

Damp squib in the Borders but not  on the the North side of the Central Belt.

[Frosty.]

I would take the ukmo / Gem 12z at T+144 as they are the best looking in terms of a colder start to march.

[Ali1977]

ECM and GFS are pretty similar at 144 and don't follow the UKMO which is a shame 

[knocker]

Perhaps, hopefully, a continued little improvement of this in the ext. period later with a little upward trend with the temps.

Edited February 23, 2017 by knocker

[Summer Sun]

Not much agreement at D7 from the main 3 over the UK

 

[knocker]

There is little change upstream with tonight's 6-10 anomalies

The vortex is consolidated over N. canada with associated trough over N. America and a strong Aleutian ridge. Downstream some amplification in the Atlantic has created a cut off high cell in the Iceland area leaving the perennial trough orientated SE into a very much negatively anomalous Atlantic and a strong westerly upper flow which effects most of the UK. The is some dispute as to whether the pressure rise to the NW will in fact just influence Northern Britain.so this not done and dusted by any means but the general percentage play is unsettled with strong jet running east from the southern States pushing systems through. Temps variable but around average

In the 10-15 period there is a suggestion of the Vortex weakening a tad and slipping a little NW with the trough over Alaska. But still the negatively titled trough into the Atlantic  With positive anomalies and ridging over Iceland the question is, as the westerly upper flow weakens, how much ridging north over the UK towards the Iceland HP will take place. The EPS is not keen at all with the flow WSW and temps a little above average.. But at the moment in the pending file.

Edited February 23, 2017 by knocker

[Ruzzi]

7 hours ago, Snowyowl9 said:

Reality check it turned out to be a damp squib,I know somebody who lives there.

I don't know where your friend stays but I'm sure they don't stay in the whole of central and southern Scotland, also I know that English and Welsh news most likely wouldn't have went into any detail as to the snow etc up here but it was carnage for parts of Scotland including where I stay. It was different from what was forecast but certainly not a damp squib, 2 major motorways completely closed for a few hours, countless accidents and gridlock through-out parts of the country, schools closed, power outages, public transport cancelled, and some places cut off with inches of snow - no damp squib! 

The models had pinned down the borders and central belt area to be worst affected but the front travelled further north than forecast meaning that the worst affected was northern parts of the central belt up into central Scotland, Perthshire, fife, Stirlingshire and Aberdeenshire. The borders escaped the worst but models did not suggest a damp squib before hand it certainly was no damp squib for large parts of Scotland.