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

[Cheshire Freeze]

Not too shabby....

 

[knocker]

http://www.meteociel.fr/modeles/ecmwf/runs/2013122512/EDH101-168.GIF?25-0

 

Day 7 Ensemble MEAN strong correlation with the ECM operational -

 

Also a good strong declining curve to day 15.

 

Expect a colder ECM DET 32 on the next update.

 

A while to wait- but our best chance of cold so far this winter......

 

S

 

Excuse my ignorance but what exactly is a strong declining curve in meteorological terms? And isn't day 15 getting into fairy land territory?

Edited December 25, 2013 by knocker

[Jason M]

Don't buy the post 192 evolution. As soon as it hits the low res part of the run everything speeds up and the jet blasts through. ignore post 192 IMHO as whatever follows will be complete rubbish.

[Cheshire Freeze]

Here we go...

 

[Cheshire Freeze]

Don't buy the post 192 evolution. As soon as it hits the low res part of the run everything speeds up and the jet blasts through. ignore post 192 IMHO as whatever follows will be complete rubbish.

 

I don't want to ignore FI though......it's showing the building blocks to the mother of all easterlys

 

[Jason M]

I don't want to ignore FI though......it's showing the building blocks to the mother of all easterlys

 

Doesn't make it right though ;-)

Tbh I think that may be where it would have headed anyway even if the resolution had not dropped at the crucial moment in the run.

[Cheshire Freeze]

Oh and here she comes....get to this point and the cold is locked in & my Jan forecast of 2-3C below average becomes a distinct possibility

 

[The Northern Ramper]

If you reckon this is square one..http://cdn.nwstatic.co.uk/ecmimages/20131225/12/npsh500.240.pngthen is suggest you learn how to read weather charts.

To be fair he appears to be a newbie, however the poster who liked his post has been on here for a while now and doesn't have that excuse.That chart is the best set up we have had this winter.

[Cheshire Freeze]

Doesn't make it right though ;-)Tbh I think that may be where it would have headed anyway even if the resolution had not dropped at the crucial moment in the run.

 

I'll lay my cards on the table....bar December 2010, January 2014 will be the most severe winter month we've seen during the Netweather era.

[Duane S.]

Anyone who finds fault with tonight's 18z frankly needs their head examining. It may well not verify but what an outrageous run from the GFS to finish off Xmas day! Hardly unexpected either.

[ITSY]

trends people, trend. take detail with a pinch of salt, but very nice to see a new trend developing on Christmas day - lets hope it continues. Night all.

[The Northern Ramper]

I'll lay my cards on the table....bar December 2010, January 2014 will be the most severe winter month we've seen during the Netweather era.

Blimey that's a bold statement CC

[SnowObsessor90]

Have earlier runs this week hinted at something different? or is this simply a matter of less data input during the Christmas period?

[Duane S.]

Blimey that's a bold statement CC

A bold statement but I know where CC is coming from. I think there will be severe cold ahead in January for certain Mid-Latitude areas in the Northern Hemisphere. Fingers crossed the UK will be included!

[weatherguy]

Blimey that's a bold statement CC

 

No, this is a bold statement 

 

(sorry mods, christmas cheer 'n all that!)

 

More serious note, continued trends showing -AO and disrupted PV with a complete split by +160h on this latest run.  Plenty to be happy about, let's hope we're positioned well to take advantage and we have some stonkers in a realistic timeframe a week from now

[Captain Shortwave]

I'll lay my cards on the table....bar December 2010, January 2014 will be the most severe winter month we've seen during the Netweather era.

Audacious, lets hope it bears fruit very soon. Though I would like to be able to get to work

[bobbydog]

Don't buy the post 192 evolution. As soon as it hits the low res part of the run everything speeds up and the jet blasts through. ignore post 192 IMHO as whatever follows will be complete rubbish.

 

i don't think its rubbish really,

 

at +156 we have low heights over the pole and a weak ridge pushing into scandi-

 

 

by +174 we see these heights linking up-

 

 

at +192 we have enough HP over north-east europe to start the jet on a more southerly track-

 

 

 

the jet may "fire up" but this energy blasts into southern europe

 

 

this leaves a void for the atlantic ridge to push towards greenland-

 

 

hello mr winter.... we've been expecting you.....

 

 

Edited December 25, 2013 by bobbydog

[Jason M]

I'll lay my cards on the table....bar December 2010, January 2014 will be the most severe winter month we've seen during the Netweather era.

 

Good stuff

 

I'm going for an easterly, but I think it will be mid month and of the standard winter variety rather than severe.

 

Goes without saying that I hope you are right rather than me!!

[Frosty.]

Today's met office updates are a welcome boost for coldies seeking snow and ice, its a marked change in tone from the flat zonal slightly mild outlook and now implies a rather more amplified upstream pattern with the jet tending to align northwest / southeast enabling the very cold air blasting out of canada into the north atlantic a faster track to the uk. It feels like being given an extra christmas prezzie. : -)

[weather eater]

Have earlier runs this week hinted at something different? or is this simply a matter of less data input during the Christmas period?

Not sure whether less data is fact or fiction it’s been mooted before and I can’t remember what the conclusion was, however, one thing is for certain and that is that Christmas day/Boxing day has turned up some odd outputs before, although not last year, it would be great if this is a real trend but I’d stay on the fence for a couple of days before getting more confident.

[Ali1977]

Fantastic set of Ens coming out, best of the winter so far I'm sure..

[Barry12]

Sorry, but this 'less data' is a complete myth...

[Mucka]

Not sure whether less data is fact or fiction it’s been mooted before and I can’t remember what the conclusion was, however, one thing is for certain and that is that Christmas day/Boxing day has turned up some odd outputs before, although not last year, it would be great if this is a real trend but I’d stay on the fence for a couple of days before getting more confident.

 

Not trying to blow my own trumpet or anything but I was talking about this trend just after mid month along with one or two others so it has been in the output for quite a while as at least a weak signal.

What we are seeing is a gradual firming up of the signal and the possible benefits from any blocking being modelled.

We are not there yet though and still a way to go before we start to see decent snow chances to low levels - I still fancy Northern England will see a good snowfall in the first half of Jan and the South could see some transient snow too but any deep cold, should we get it, will likely come toward and after mid month if blocking establishes itself.

 

GFS ensembles 18z SE England

 

http://www.meteociel.fr/cartes_obs/gens_display.php?ext=1&x=288&y=122

 

ECM 12z London ensembles

 

Edited December 25, 2013 by Mucka

[Purga]

 

Blow the wind easterly, easterly, easterly,
Blow the wind east o'er the bonny cold sea;
Blow the wind easterly, easterly, easterly,
Blow bonnie breeze, my snowfest to me.

 

They told me last night there were blizzards in the offing,
And I hurried down to the deep freezing sea .
But my eye could not see it wherever might be it,
The shortwave that is bearing my snowfest to me.

 

Blow the wind easterly, easterly, easterly,
Blow the wind east o'er the bonny cold sea;
Blow the wind easterly, easterly, easterly,
Blow bonnie breeze, my snowfest to me.

 

Oh, is it not sweet to hear the frigid breeze singing,
As lightly it comes o'er the deep freezing sea?
But sweeter and dearer by far when 'tis bringing,
The shortwave of my snowfest in safely to me.

 

OT - soz Mods but full of Christmas cheer - have  agreat Christmas folks and a snowy and brilliant New Year!!

 

Purga....

Edited December 26, 2013 by Purga

[nick sussex]

Evening all

 

Hope everyone enjoyed their Xmas.

 

Looking at the outputs I was  somewhat underwhelmed by the morning runs but pleasantly surprised after just catching up with the 12hrs outputs.Overall it looks like it will need two attempts to finally change the pattern unless that is we can see much more trough disruption around T168hrs.

 

Upstream NOAA's comments from the afternoon do give a green light for at least some energy heading more se into Europe:

 

THE BIG NEWS IS THAT THE FLOW OVER NORTHAMERICA APPEARS TO BE GOING INTO HIGH-MERIDIONAL MODE AT THE ENDOF THE MEDIUM RANGE, WITH A DIRECT TRANSPORT OF ARCTIC AIR INTOTHE EASTERN UNITED STATES AFTER THE TURN OF THE YEAR.

 

So with the pattern becoming more amplified over the eastern USA this downstream normally correlates with the Azores high displacing further west, given the models want to keep some high pressure to the ne then troughing normally aligns nw/se into Europe.

 

I don't think at this stage however that there should be a stampede to the nearest sledge shop! Getting the jet axis more favourable is just one step, the key really is whether energy can completely separate itself from Greenland, if this doesn't happen then you at least need the pattern further west. The best scenario is one where the Azores high ridges north to the west, pressure builds in from the ne, the two in tandem force shortwave energy to clear into mainland Europe and then the ridge can extend further west towards eastern Greenland.

 

The wind direction ECM ensembles are a good indicator of the uncertainty re what happens after the initial change to a more nw/se alignment:

 

 

You can see the solid grouping for the next week then a large spread of solutions.

 

Somewhat frustratingly the models are reluctant to do the decent thing and save us a lot of stress by simply disrupting the troughing around day 7 because then that would be the pattern change done and dusted!

 

 

The ECM eventually develops a good chart at day ten but these charts seem to have been stuck at that point on many occasions over the last month!

 

Positively the UKMO tonight does look more amplified and that's always the model that is the deciding judge in these situations.

 

Overall then a trend to colder conditions does look likely but in terms of how cold or snowy I still think that's uncertain,  with events in the strat likely to cause some model volatility over the next week lets hope we end up with the Royal Flush and a quick cold resolution!