Model Output Discussion 17th Dec.2013-12z onwards.

[Gaz1985]

I think floods will be in the headlines again over the next 2 weeks. Looking very wet at times.

 

 

 

 

[UV-RAY]

I think the two main points for a route to cold are the jet digging South on the NE/SE trajectory  and the lowering of heights over Europe, these for me are crucial regardless of whether we have HLB at this moment in time. The trend is for colder than average temps from around the 10th onwards and with plenty of toughing in favourable positions then it's only a matter of time before somewhere from the North Midlands Northwards sees low level snowfall, and then who knows maybe a push from the East.

[MR EXTREMES]

Hi EML-

 

Its the 3 ridges- Scandi / Atlantic & Kumchatka.... A tripod of ridges if you like-

Seen here

http://modeles.meteociel.fr/modeles/gens/run/gensnh-0-1-288.png?6

 

Eventually the cold sinks south-

S

 

SOME of the 06z ensembles are pretty good!

indeed steve a lot of really cold set ups come from this type of multi ridging as chino say mid moth will be when we see the real action take effect and the models clearly are toying with the ideas,

 

a few days ago there was cross model agreement but they all have there own ideas atm!

soits a case of keep watching in the areas steve and chino are talking about.

Edited December 28, 2013 by emotional rollercoaster

[nick sussex]

Ironic that just as the Euros downgrade the Scandi Ridge that the GFS 06hrs run increases it from its earlier outputs, there are even a few ensembles that develop some trough disruption near the UK at 168hrs.

 

There still looks to be some uncertainty as to how much of the Canadian PV drains east and this probably is the cause of the mix of options shown on the GEFS at that timeframe.

 

Overall it looks like unless theres some last minute backtrack that this energy from the PV will flatten the pattern out initially pushing the ridge to the ne further east and its only after this that the pattern could develop more favourably for cold.

[UV-RAY]

Looks as if the MetO are now slowly climbing on board the cold express with the prospects of significantly colder weather possible towards the latter end of January. 

[lassie23]

The cold keeps getting pushed further and further into January. It was looking as though snow would be falling on the 10th of January, now not looking so likely.

[Frosty.]

The Gfs 06z op run remains very unsettled throughout, no sign whatsoever of the weather settling down and in addition to it continuing unsettled, it also shows an increasing frequency of cold incursions from the west / north west as time goes on, even through next week there are a few incursions of 528 dam thicknesses and if anything, further on there are even colder incursions at times with the jet generally further south than normal, there is also a chance as lows sweep in off the atlantic, the in-situ rather colder pool of air over the uk could bring a higher risk of sleet and wet snow on the leading edge of frontal systems and more generally the further north you are. The risk of sleet and snow (especially across hills) becomes significant with a cold westerly air stream of arctic origins for much of the time and mild weather is really at a premium, very short lived milder interludes which barely register on the mild blipometer, temps occasionally reach average levels but are regularly just below average or rather cold with an increasing risk of wintry ppn, frost and ice, and occasional stormy, slightly milder days with yet more flooding on the way.

Edited December 28, 2013 by Frosty.

[NO LONGER POSTING]

interesting chart...

 

High pressure building into the Atlantic...

 

Bearing in mind this is +384 hours right at the end of the GFS run... But boy what a storm..

 

[winterof79]

The cold keeps getting pushed further and further into January. It was looking as though snow would be falling on the 10th of January, now not looking so likely.

I have not seen any charts showing widespread snowfall as yet for the date you mentioned.Although i stand to be corrected.Edit.Maybe FI output Edited December 28, 2013 by winterof79

[Purga]

Well just read the tail end of the METO 30 dayer and had to do a double take!

 

"Some signs are also emerging suggesting temperatures being less mild in general terms than the last couple of weeks, and perhaps even significantly colder late in the month."

 

Apologies I guess this is the wrong thread but does anyone have an idea (Ian F?) what they have spotted in the models to suggest this?

 

Edit: Ahh.. sorry Sceptical Inquirer you beat me to it!

Edited December 28, 2013 by Purga

[tinybill]

looking at  the models  there  looking like some  they stormy weather to hit  the  uk from 31  DEC  -Jan 4 at the  moment

http://www.meteociel.fr/modeles/gefs_cartes.php?code=16&ech=6&carte=&mode=0

[bluearmy]

Well just read the tail end of the METO 30 dayer and had to do a double take! "Some signs are also emerging suggesting temperatures being less mild in general terms than the last couple of weeks, and perhaps even significantly colder late in the month." Apologies I guess this is the wrong thread but does anyone have an idea (Ian F?) what they have spotted in the models to suggest this?

It can only be their strat model. The same thing occured in previous winters but we were well preppd by stewart to expct a warming so it tied in. This would seem to be a bit earlier than ed was thinking though not by too far.

[Mucka]

Ironic that just as the Euros downgrade the Scandi Ridge that the GFS 06hrs run increases it from its earlier outputs, there are even a few ensembles that develop some trough disruption near the UK at 168hrs.

 

There still looks to be some uncertainty as to how much of the Canadian PV drains east and this probably is the cause of the mix of options shown on the GEFS at that timeframe.

 

Overall it looks like unless theres some last minute backtrack that this energy from the PV will flatten the pattern out initially pushing the ridge to the ne further east and its only after this that the pattern could develop more favourably for cold.

 

Having just read the last couple of pages of analysis I was going to post that a lot of assumptions are being made that the 5-7 day output has been nailed but for me there is no evidence of this so your post was a welcome reminder of that.

 

There is still no run to run consistency or cross model consensus on how strong the ridge will be and how much trough disruption we will get behind, how the jet will align itself and consequently how much energy we can force SE into Europe. The chunk of PV that has had things all its own way over Canada is being shredded, with the main chunk on the move East around day 5, but there is no real way to know the consequences of this until we have it modelled with some consistency in the output.

This is why there is such divergence of solutions by day 8.

 

There is no quick route to deep cold, never has been, but the building blocks have been delivered and unloaded, now the construction begins.

I still fancy we will see more cold incursions to the North than currently expected by some and snow will fall to low levels before we reach mid Jan as expect the flow to be further South with more disruption at the end of the first week and through the second week of Jan than is generally being modelled.

There will be a lot of wind and rain around at first but I think we have seen the back of the very severe storms we have seen in December and this weakening of the strength of Atlantic systems will be more noticeable in the second week.

 

Currently ECM has that main chunk of residual PV energy (trough) sat over the North of the UK by day 8 with a very slight NW/SE tilt.

 

 

I wouldn't be at all surprised if that is further SW with a greater NW/SE tilt come the time with the prospect of weak blocking to the North and a more amplified pattern setting up behind. That would set up a colder flow through the second week and open up the possibility of some decent snowfall (again transient) even to low levels in the North of England with the potential for blocking to take hold in the second half of January with the chance of ridging in the Atlantic once it has been tamed.

 

Nobody loves a good FI more than me but keep a close eye on developments from around day 5 because there is still a good chance of some fairly significant changes in the output through to day 8 even if conditions for us here on the ground look to be more of the same for the time being.

Edited December 28, 2013 by Mucka

[Ali1977]

Although a once in a lifetime event( they say) The 1947 winter didn't really start till mid to late Jan, and look what happened there. Although extremely unlikely, the coldest ever winter is still a possibility...

Just saying!!!!

[Paul]

Just a reminder, this is a model discussion thread so if your post isn't related to the model output please post it into another more relevant thread

[weather eater]

I rather suspect myself that any colder incursions will be few and far between in the next 10 days, (I hope I’m wrong) yes the pattern is not nailed, but then it rarely is and there will be corrections, however that usually means corrections further north in my experience of the models. I think what counts is getting the building blocks for something better down the line, and not worrying about what happens locally in the next few days, besides transient snow on the hills may be all well and good for some but living in high peak I’ve already seen a couple in the last week and they don’t really do it for me, cold and snow is great but a dribble, a smattering on the ground and a bit of sleet why bother.

[Cecil Hogmanay Melchett]

The meto update is a big ray of hope for all us coldies.

The models although not screaming coldfest are at last beginning to show signs of promise with the emergence of blocking cells north of scandy.

While that might not be a fast track to cold for the UK it will certainly help in the process of 'slowing down' the Atlantic and hopefully with time push the PFJ further south.

[SMU]

Well finally after 3 days the GFS has finally caught up with the Euros

 

http://modeles.meteociel.fr/modeles/gfs/runs/2013122812/gfsnh-0-150.png?12

 

note the strong Scandi ridge.

 

Lets hope that can come into play at day 8-10

 

S

[cooling climate]

The Euro models were on the ball with the hights in the north feeding into northern

Scandinavia and nw Russia. The GFS is now doing the same and what this shows is

the Siberian high is expanding west. Another Asian mountain torque which should

occur within the next 10 days or so should help to expand it even further west imo and

by then the longer range outputs from the GFS should start to look a lot more exciting

and consistent for winter weather lovers as for the last fornight of Jan and then into

February.

[SMU]

http://modeles.meteociel.fr/modeles/gfs/runs/2013122812/gfs-2-162.png?12

 

Quite a snowy run for the west & Wales....

 

S

[shaky]

http://modeles.meteociel.fr/modeles/gfs/runs/2013122812/gfs-2-162.png?12 Quite a snowy run for the west & Wales.... S

thats a surprise!!its come out the blue!!there was no snow at all showing in the previous runs!!lets see what the ukmo ukmo makes of it!!

[Polar Maritime]

Something BFTP mentioned this morning.

[East_England_Stormchaser91]

Still think that mid to late jan is when we may see some proper cold, and more so into February. The change will happen, patience is just required!

[IDO]

The less said about the GFS 12z op the better. It takes 16 days to get here: 

 

With little interest in between (barring transient snow as above). However it looks a little bit of an outlier based on recent runs. By T168 it sends the Arctic High towards West Canada:

 

 

By T216 this HP cell eases the Canadian vortex east and tramples over the GH. We lose all our heights in our NH sector:

 

 

Back to square one from there.

[swfc]

nothing in the 12z of much interest imo,pretty breezy wet spell with the odd ridge ete but nothing out of the normal