Winter Model Discussion 18Z 8/1/13. The hunt for cold (is closer).

[Cheshire Freeze]

I do like the way the big three, ECM, UKMO, GFS, all agree and yet we are all still cautious and looking for other models/more evidence that this will actually happen. Funny that some of us in here have been bitten in the past. If these three models agreed as they do now, a few years ago, we would all be ramping like mad right now

edit: and of course, Ian (and a certain WIB) would be fighting against the cold right up to T+0 !

We've all learned some harsh and cruel lessons over the years.

This year where any cold spell is considered, 72 hrs seems to be the point where FI begins.....denoted perfectly by the December fiasco

[Nice Ice Babe]

Hello all

I have been lurking on here reading the strat thread last winter and all this. This year I have added these threads to cross refer to the models to further enhance my complete novice understanding and I am now totally hooked and very excited too. So for my first post, I don't have anything intelligent to add to the model discussion, except it will snow and it will be cold.... very cold. How do I know this?.... M&S have already started putting summer sandals on the shelves.

[Wayneywoo]

Up to T+48 and nothing worth mentioning that is different thus far.

[karlos1983]

Things look same at +48

[picog]

Short ensembles right down the middle of the fairway

Lovely.

But potentially snowless? Very dry. Maybe we should not worry too much yet about the depth of snow, just get the cold into place.

[Allseasons-Si]

Sorry mods about that vid,the wrong thread

back to the model thread

mcweather posted this earlier of the 81 big freeze

does anyone know what timeframe this was shown before it actually happened cos ecm looks alot like it at 168hrs

Si

[damianslaw]

Good to see strong agreement between ECM and UKMO/GFS tonight for the reliable timeframe - a good sign that the models are getting to grips with changes taking place in the upper atmosphere over the northern hemisphere, which have for a long time if you read the Strat thread suggested strong height rises over Greenland - not straight away but eventually.

The key to unlocking a much colder outlook is the low pressure system moving down from southern greenland on Friday and into the weekend, the models are showing this tracking on a SE trajectory which helps to quickly build heights to the north - the deeper the low the greater heights will rise to the north and therefore the easier it will be to pull in the developing cold uppers from the east.

The polar vortex is becoming a very weak affair now and the atlantic is losing all energy, I doubt any shortwave features off southern greenland if they did verify would have any oomph to them, and all signs that such features would simply drop SE and anchor to our SW retaining the cold pool to our NE.

The models are all showing a clear path for retrogression of heights from scandi to Greenland quite quickly. Its been a superb day for cold snow lovers, but as ever caution is the word.

[Continental Climate]

snow bearing uppers almost on us at t60 http://modeles.meteociel.fr/modeles/gfs/runs/2013010818/gfsnh-1-60.png?18!!

[Southern Storm]

Ianf Just posted over on SW Regional - prep yourselves for a downgrade

"PS latest UKMO analysis just received doesn't - on face value - look very wintry at all for most of southern England through weekend - exception being E districts /E Anglia / SE on Sunday and potential for some leading and back edge falls later Sat and again Sun, but UKMO v uncertain on N'ward extent to this. Monday mostly dry in their prog with exception of snow in far SE. Their modified GM fields looks nowhere near as snow-bound as the raw GFS indicated, for example, but take with suitable salt pinch.... will probably see MOGREPS and other snow probs etc later this eve."

well in the south west at least...

Let's not over react people, I don't think he's saying it won't happen.

we all know that the models will Struggle with the amount and placement of any precipitation, so don't worry just yet!

[SMU]

http://www.knmi.nl/exp/pluim/vijftiendaagse/index.html

best set of long ensembles of the winter-

S

[Nimbus Nix]

http://www.independent.co.uk/news/uk/home-news/subzero-temperatures-set-to-drop-as-low-as-15c-next-week-with-cold-weather-front-lasting-until-february-8442886.html A cold front lasting a whole month...? That's a new one...! Looks like the papers have caught on with the cold though...

[karlos1983]

Good to see strong agreement between ECM and UKMO/GFS tonight for the reliable timeframe - a good sign that the models are getting to grips with changes taking place in the upper atmosphere over the northern hemisphere, which have for a long time if you read the Strat thread suggested strong height rises over Greenland - not straight away but eventually.

The key to unlocking a much colder outlook is the low pressure system moving down from southern greenland on Friday and into the weekend, the models are showing this tracking on a SE trajectory which helps to quickly build heights to the north - the deeper the low the greater heights will rise to the north and therefore the easier it will be to pull in the developing cold uppers from the east.

The polar vortex is becoming a very weak affair now and the atlantic is losing all energy, I doubt any shortwave features off southern greenland if they did verify would have any oomph to them, and all signs that such features would simply drop SE and anchor to our SW retaining the cold pool to our NE.

The models are all showing a clear path for retrogression of heights from scandi to Greenland quite quickly. Its been a superb day for cold snow lovers, but as ever caution is the word.

Thanks for that, it's nice to know what we need to be looking out for in the model runs to get everything in place as a relative amateur.

I can't wait to be able to show caution the door for a change!

[chionomaniac]

But potentially snowless? Very dry. Maybe we should not worry too much yet about the depth of snow, just get the cold into place.

And remember they are for de Bilt which could be drier.

Longer ensembles steady as well.

[frozen bluebird]

Steve i struggle to understand those graphs. What I am I looking at?

Thanks to everyone for the info. Its very informative and I cant leave it alone. Sorry Chino off topic

[I remember Atlantic 252]

Steve i struggle to understand those graphs. What I am I looking at?

I am never sure if the bottom left is the 850 temps or the 2m temps? I know for holland

[Allseasons-Si]

http://www.knmi.nl/e...agse/index.html

best set of long ensembles of the winter-

S

yes steve also plenty of snow spikes on there too in in short to mid range(on the bottom right chart for the new members that don't understand).

Si

[Cloud 10]

Latest fax chart at 72 hrs has everything nicely poised.

I look forward to the 96 and 120 hrs updates.

[SMU]

Steve i struggle to understand those graphs. What I am I looking at?

Thanks to everyone for the info. Its very informative and I cant leave it alone. Sorry Chino off topic

really bottom left is the T2M temps for debilt holland- shows the dotted mean at freezing for 16 days-

The bottom right is the snow spikes- however in an easterly we get the benefit of the north sea...!

S

[frozen bluebird]

So bottom right is cm of snow, for Holland?

[Harsh Climate]

Out to 90h, almost identical to 12z which must be a good sign

[Continental Climate]

Well, according to the gfs the extreme east starts off its cold spell at t84 http://www.wetterzentrale.de/pics/Rtavn841.png!! Uppers probably just condusive http://www.wetterzentrale.de/pics/Rtavn842.png!!

[Bobby]

The snowfest for parts of the S still on for Saturday

[snowice]

^{_{so far so good !low still south of Ireland}}

[bryan629]

hey steve the jetS splitting WHOOP WHOOP

Edited January 8, 2013 by bryan629

[cold snap]

http://www.meteociel.fr/modeles/gfse_cartes.php?&ech=96&mode=0

Only at 96 hours excellent chart