Winter Model Discussion - The Hunt For Cold -12z 14/12/12

[TEITS]

Despite the poor ECM ensembles im still not convinced.

Every time I look at the GFS in the early timeframes I see a correction with the HP slightly further W and the LP slightly further S. Im also beginning to wonder about the other LP in the Atlantic and how this may take more of a E,ly track rather than a NE,ly track because im not convinced about the increase in heights over Iberia and how they force the LP NE.

We shall see!

Just add all my forecasting is based on instincts and my instincts are telling me all the current model output is wrong.

Edited December 16, 2012 by THE EYE IN THE SKY

[LomondSnowstorm]

Despite the poor ECM ensembles im still not convinced.

Every time I look at the GFS in the early timeframes I see a correction with the HP slightly further W and the LP slightly further S. Im also beginning to wonder about the other LP in the Atlantic and how this may take more of a E,ly track rather than a NE,ly track because im not convinced about the increase in heights over Iberia and how they force the LP NE.

We shall see!

Just add all my forecasting is based on instincts and my instincts are telling me all the current model output is wrong.

Pub run is certainly running by your script of continual upgrades at least, cold uppers heading into northeast Scotland by +102, much healthier looking undercut too than the 12Z.

[Matty M]

18z a tease again in the early stages.

Again we would really like to see that energy pulse into Fitzroy near T102hrs to develop.

[swfc]

At 114hrs this is so close.The ridging from the south is and needs to do one asap

[Methuselah]

An eventual easterly does look to be possible...if it were not for the models' going out past 5 days, we'd only be able to see into the 'reliable' time-frame, anyway...And, if last week's 'nailed-on' 'dead-cert' BFTE could be so patently erroneous, so can any other forecast?

The 'blow torch' also seems to be being scaled down. So who knows?

[Matty M]

Jet profile probably not as favourable as the 12z, so the Atlantic depression more likely to run NE rather than ENE

[TEITS]

Pub run is certainly running by your script of continual upgrades at least, cold uppers heading into northeast Scotland by +102, much healthier looking undercut too than the 12Z.

Yep i've always fancied NE Scotland being favourite and continue to do so especially with regards to the 18Z.

Good the SW becomes separated from the LP.

[Matty M]

There's going to be an airmass collision somewhere over Scotland on this one.

[Isolated Frost]

Snow into NE Scotland at D5- another solution, and another unresolved matter to come across, I am more interested in the pv reaction to the strat-tropo feedback in further fi and following ensembles-

definitely trending away from mild, especially in the north (parts of Scotland always were below 0c in terms of 850s)

[snow1975]

There's going to be an airmass collision somewhere over Scotland on this one.

And potentially a lot of snow

[TEITS]

This is pretty much the scenario I described a few days ago.

A brief E,ly flow bringing a snow to rain event.

http://www.wetterzentrale.de/pics/Rtavn1321.png

Still scope for improvement though over the next few days.

[Rollo]

Noting Old Met Man's post ,I too remember quite a few occasions in the fifties and sixties when such

battleground situations occured

Off course the information that we have these days is far more extensive to what existed back then, but I vividly recall at the last minute the cold air succeeding despite the previous

evenings forecast of a mild few days. Times have changed of course and in recent times the mild air has won.

I just wonder given the complexity of the situation we are in whether the multi million pound computors have it right this time.

.

[Matty M]

It's half good half bad here.

The initial easterly push is better but the Atlantic attack angle is all wrong.

we need a wave to develop into a LP in the fitzroy/biscay area in the 108hrs section to push the flow East rather than NE.

Edited December 16, 2012 by Matty M

[kev238]

every gfs run today has brought the risk of very cold winds from the east that little bit closer... still unlikely to get all the way south but definitely a great chance for the far north east of scotland

Lots of rain seems inevitable whatever solution ends up being correct

[Matty M]

Just look at that WARM plume advect north and smashing into the cold northeasterly, just a few hundred miles away from Snowmageddon

Edited December 16, 2012 by Matty M

[nick sussex]

The models seem determined to drag this saga on and on!

If this run verified the UKMO would be having a nightmare to make a forecast. The real problem is that as the troughing pivots it pushes the Azores high ne towards the UK.

The juries still out,its all very finely balanced where small changes earlier can make a difference especially for the north and ne of the UK.

[Zakos]

Another huge shift west from the GFS, it ridiculously over estimated the strength of the Atlantic a few days ago.

We only need one more shift west. Can we get it? Tommorow will reveal all I think. Going to be a tense day for model watchers i feel.

[BARRY]

Don't wont to look beyond 96hr as it will change so much over the next few days

[Weathizard]

Is it normal to have such excessively warm uppers to our south? They look very high considering its winter for the NH? I am very worried for us southerners though, as the worst effected areas are in the line of fire for the rain again! Don't think it will be a very merry christmas for some if current charts are correct

Hope we either get a big shift west OR the block rides in to save us, preferably both.

Edited December 16, 2012 by Weathizard

[southbank]

The trend still being signalled with heights rising over Iberia , that's going to provide a lot of frustration this winter

[peterf]

all looking good as far as i'm concerned.

[Tim Bland]

Black oc line on the below chart clearly showing the wall of cold to our east at day 8 still. This cold block to our east really doesn't want to shift. It either needs to push west so can we can join in... or do one!

I see GP is online.. What's your thoughts Stuart is looking east a red herring?

http://www.meteociel.fr/modeles/gfse_cartes.php?ech=174&code=0&mode=1

[snow1975]

Black oc line on the below chart clearly showing the wall of cold to our east at day 8 still. This cold block to our east really doesn't want to shift. It either needs to push west so can we can join in... or do one!

I see GP is online.. What's your thoughts Stuart is looking east a red herring?

http://www.meteociel...4&code=0&mode=1

More like a blue, frozen herring!

[Weathizard]

Its an absolute titanic battle though, the Atlantic is just weak compared to the strength and power of that block, but I just cant see a big enough shift west/south to get us all in on the action and fun. I suppose its a possibility but at this current time I'd be 75% sure the block JUST wont move west enough for anyone away from the far north/NE.

Anyone convince me otherwise?

[karyo]

I can't see a northerly coming anytime soon with the Russian high getting stuck to the east and us locked in mild Atlantic air!

http://www.netweather.tv/index.cgi?action=nwdc;sess=

Karyo

Edited December 16, 2012 by karyo