General Model Output Discussion Tuesday December 22Nd:

[Shunter]

very little difference netween the 06z & 12z op runs on GFS at T+168

[Eugene]

LOL.... it really has come to something when people on TWO are moaning about temps like these, 4C in the midlands hardly constitutes a mild spell, really a very disappointing run for mild weather fans they may scrape the odd average day in the midlands and thats all for them, looking very promising still for cold weather fans, excellent trends in only december, cant really ask for more really

http://www.wetterzentrale.de/pics/Rtavn15017.png

http://www.wetterzentrale.de/pics/Rtavn1741.png

[Barb]

I expect the GFS is overdeepening the low on 29th as usual. Met Office have it as 985 or so while GFS has it at 965.

[swfc]

Amazing run and not much to say really.if it comes of hold on tight.

[Barb]

Looking brilliant in FI.

What a chart.

[The Weather Dragon]

Stunning 12z Run - quite a plausible evolution - falling into line with ECM

[tinybill]

Looking brilliant in FI.

What a chart.

all say is if the uk dont get snowed in or get a good dumping i give up !!

[cooling climate]

The 12z run is different to the 06z in the fact that the block over the Arctic pushes across the pole towards

Greenland rather than letting the vortex over Scandinavia traverse across to Canada with the high coming

around the eastern flank of the vortex.

The evolution is still a very cold one for Europe and the UK and could in fact be even colder than the 06z

run as part of the vortex is made to drop down into Scandinavia.

Another excellent run for winter weather lovers.

[West is Best]

Amongst the most sensational 12z GFS runs you're ever likely to see. However ...

I want to see greater ensemble support for this evolution than was apparent with the 6z. We also need to remember that the real meat n' 2 veg of this is still out at T144+.

On the plus side though, this prognosis has the absolutely hallmark of plausibility to me: it's almost the likely outcome of the high pressure build over Greenland, the southerly Polar Front Jet and the buckled jet.

This winter is already reminding me so much of 1978/9.

[Barb]

Comments on the UKMO 12z anyone?

[Methuselah]

Well, if that pans out, I'd welcome a mild spell!!!

[Geordiesnow]

I expect the GFS is overdeepening the low on 29th as usual. Met Office have it as 985 or so while GFS has it at 965.

Which probably won't be a bad thing in all honesty because mild air will struggle even more to get into the uk and therefore, it could mean colder uppers in the South.

On a IMBY POV, i would like the low a little bit further South so my area have got much chance of getting convective showers however details will change and nothing is set in stone by a long shot.

[bluearmy]

excetional run to run continuity from GFS with the D11 charts showing identical patterns with the newer run having the grrenland block a few hudred miles west of the 06z but splendid potential for the new year. the UKMO looks to be headed the same way in a weeks time.

[Barb]

Which probably won't be a bad thing in all honesty because mild air will struggle even more to get into the uk and therefore, it could mean colder uppers in the South.

Yes I agree it would generally be better for the south. Major snow event for Central/South Britain still seems to be on.

[Frosty.]

Another wonder run from the GFS 12z with an arctic blast, it takes a while to get going but when it does get going it's a really severe outbreak of polar air. The southward ridging from Greenland is very impressive, similar to the early stages of the current cold spell. In the meantime though, central and southern britain will become less cold with temps between 5-8c but as high as 10-11c on the southern coastal strip and the cold air over the northern half of scotland will never be displaced before the next blast of arctic air begins to push south. A real wintry feast in FI with heavy, frequent snow showers and N'ly gales with sharp frosts, eventually the greenie ridge is blasted away by a deep atlantic low but the alignment of the scandi trough and high pressure to the north west is just about perfection on this run, the scandi trough just expands westwards...AMAZING

[Snowmad79]

Stunning 12z Run - quite a plausible evolution - falling into line with ECM

I could be mistaken but im pretty sure its vice versa and that the Euro/s are or were falling inline with what the GFS was showing yesterday morning on the 00z.

Either way a another decent run from the GFS .. it really is shaping up to be a spectacular winter !.

[Neilsouth]

Either way a another decent run from the GFS .. it really is shaping up to be a spectacular winter !.

Depends on where you live , it's been very poor here while fantastic further west.. Not everywhere has seen snow , would be fantastic for countrywide snow even though!

[TEITS]

Well, if that pans out, I'd welcome a mild spell!!!

How dare you say such a thing on this thread.

Another stunning 12Z which continues to suggest the AO remaining deeply negative!

I shall refrain from getting excited unless this trend continues till xmas day. I shall then return from my xmas dinner and my mothers fabulous xmas pud and if this trend continues I shall be in full ramp mode.

[Andy_]

i'm sorry but de ja vu much?

ive been away from the models for about a week now, mainly to enjoy the weather we have at the minute and not get back into the inevitable reality of mild after the cold spell, but now its showing cold again! is this a sign of the winter to come? wintry re-load after wintry re-load only for the atlantic to be blocked of as a head cold can be blocked of my paracetemol hmm, could europe be on anti-mild antibiotics this winter

looks like we could be in for another cold spell by new year folks! and i wouldnt be so cautious this time as the current spell came out with flying colours for most areas! 12Z is a great run, 06Z ensembles werent so enthusiastic but de ja vu again they came on board last time eventually right?

Edited December 23, 2009 by Andy Sabb

[kold weather]

Very good run, takes a little longer to get there in the end but the evolution is broadly similar to the 06z GFS.

Synoptics are quite stunning, we break down right at the end of the run in the most ironic way possible!

Massive upper high blows up over E.Canada and actually destroys our Greenland high!

The PV then keeps hold over Scandinavia but the massive Canadian high then slides NW and then allows the Candian vortex to slips in, then suddenly we are break into a Euro high type set-up.

That would be an amazing synoptic evolution, going to be interesting to observe!

[BLAST FROM THE PAST]

Hi Folks

I've been to Swansea for a few days and so have been off line....Have I missed something?? Wanted to get back yesterday but the Bridges were closed

Now the models clearly look good still so I wanted to give an update on my view.

Watch for this New Year storm, its going to have a big affect on the UK be it rain or snow. Gale force winds and very heavy precip, as per the LRF it is very very much game on.

Now, very cold Jan to come and it may get cold very very quickly ie from 2nd onwards and our particular LRF snow watch for 5th onwards and mid month [indeed the cold always around to the north and close by to the south and it may essentially stay 'cold' from now ]. The two weeks of lying lowland UK snow is still very much on and indeed could be longer....potential coldest month since Feb 91....yes sub 2c for me is on the cards. I think I'd say we have just had a big warning of what is to come. I'm looking for strong to gale force northeasterly winds for much of the first half of the month.

So if FI shows armaggeddon...I'm going to support it

BFTP

Edited December 23, 2009 by BLAST FROM THE PAST

[Frosty.]

Very good run, takes a little longer to get there in the end but the evolution is broadly similar to the 06z GFS.

Synoptics are quite stunning, we break down right at the end of the run in the most ironic way possible!

Massive upper high blows up over E.Canada and actually destroys our Greenland high!

The PV then keeps hold over Scandinavia but the massive Canadian high then slides NW and then allows the Candian vortex to slips in, then suddenly we are break into a Euro high type set-up.

That would be an amazing synoptic evolution, going to be interesting to observe!

It's just a pity that southern britain would be seeing temps of 5-8c until at least the middle of next week whereas areas up north will be cold and snowy from the weekend onwards.

[aspire27]

Another wonder run from the GFS 12z with an arctic blast, it takes a while to get going but when it does get going it's a really severe outbreak of polar air. The southward ridging from Greenland is very impressive, similar to the early stages of the current cold spell. In the meantime though, central and southern britain will become less cold with temps between 5-8c but as high as 10-11c on the southern coastal strip and the cold air over the northern half of scotland will never be displaced before the next blast of arctic air begins to push south. A real wintry feast in FI with heavy, frequent snow showers and N'ly gales with sharp frosts, eventually the greenie ridge is blasted away by a deep atlantic low but the alignment of the scandi trough and high pressure to the north west is just about perfection on this run, the scandi trough just expands westwards...AMAZING

Newbie question - Didnt we see models like these a week / two weeks ago showing (i quote the above) 'severve outbreak of polar air', and it never arrived in the reliable? All we got was a something very watered down.

I presume we look into FI to see new trends and patterns, but going by this week, when i thought it was to get really really cold, again it didnt come off.

Just a question - how long did we actually get easterly winds over the last ten days?

[Anti-Mild]

i'm sorry but de ja vu much?

ive been away from the models for about a week now, mainly to enjoy the weather we have at the minute and not get back into the inevitable reality of mild after the cold spell, but now its showing cold again! is this a sign of the winter to come? wintry re-load after wintry re-load only for the atlantic to be blocked of as a head cold can be blocked of my paracetemol hmm, could europe be on anti-mild antibiotics this winter

looks like we could be in for another cold spell by new year folks! and i wouldnt be so cautious this time as the current spell came out with flying colours for most areas! 12Z is a great run, 06Z ensembles werent so enthusiastic but de ja vu again they came on board last time eventually right?

Hey, that's a trademark you know!!

Excellent 12z from GFS, and as others have said, because of our current spell of cold weather I think that confidence regarding the evolution out beyond +192 is higher - if it can be done once it can be done again.

WRT the current spell, from a personal POV I would say that it reminds me most strongly of November 1993. Not because of the synoptics but because of the amount of snow, the length of time it has hung about, and the depth of cold.

[cooling climate]

UKMO is even better at t144 I think than the GFS with a 1055mb block over the pole and it is taking the

same evolution as the 12z GFS in that the block takes a direct route across the pole to reinforce the heights

building up into Greenland.