Winter Model Discussion 18Z 3/2/13 onwards.

[Panayiotis]

Is it? Atlantic on the door, could go either way but too close for comfort!

With the wedge of high pressure to the north that low has only one way to go and thats to undercut, UKMO at 144hrs shows this. If went further this would move south east bringing in an easterly wind, its v.good IMO.

Edited February 4, 2013 by Panayiotis

[Captain Shortwave]

I have to admit I now have a concern, if gfs was right all along it's pulled its trump card on this run, the Northern Norway shortwave. This destroys the Westwards movement of the Russian high.

http://modeles.meteo...nh-0-132.png?12

I hope it's just thrown that in at random and it disappears

Just for balance, UKMO is fine

Edited February 4, 2013 by Captain shortwave

[SMU]

Steve, Can you clarify; do you believe that the ECM has it spot on and is unlikely to back tract at all in the next couple of days? Im genuinely interested (and sure others are) as you are a very knowledgable and respected forum member

Thanks

Tim

HI Tim-

The ECM will be expected to be the model to have shown the way on this pattern - it appears to have been after seeing the UKMO 12z.

This is now following it in the broad sense.

The GFS well, shocking as usual.

The finer detail at 120 - 144 is up for grabs & we are at the margins on that-

UKMO is quite East at 120, & east as well at 144- where as the ECM is more west circa 300 miles.

Small model differences to be expected at day 6, & possibly more to come until T48-

however i guess you would take the middle track down the spine at this stage.

The UKMO * COULD* be right - rather like a hurricane forecast track there will be a cone of track within the ECM suite- looking at the ECM control & OP the UKMO track is EAST of the ECM MEAN & OP + CONTROL, but a plausable outcome if the jet isnt quite as amplified.

As said though the ECM looks to have nailed the overall pattern ( but we cannot pat ourselves on the back yet ) until we get full model consensus just incase the GFS solution is correct - which I would rate the chances at '2% where the low rides over the top of the scandi block.

S

Edited February 4, 2013 by Steve Murr

[Snowman.]

You can see where are problem lies.

ECM keeps that low as one GFS doesn't and seems to send energy over the block.

[SMU]

Snowmans post above clarifies exactly the faults I was highlighting with the GFS

Cannot create trough disruption- Cannot seperate 2 parcels of energy away from each other- net result shortwaves cluster together going through as opposed to seperating moving apart...

S

[Methuselah]

Snowmans post above clarifies exactly the faults I was highlighting with the GFS

Cannot create trough disruption- Cannot seperate 2 parcels of energy away from each other- net result shortwaves cluster together going through as opposed to seperating moving apart...

S

And, if the weather doesn't perform that hoped-for 'separation'? Then what?

[Tamara]

I have to admit I now have a concern, if gfs was right all along it's pulled its trump card on this run, the Northern Norway shortwave. This destroys the Westwards movement of the Russian high.

http://modeles.meteo...nh-0-132.png?12

I hope it's just thrown that in at random and it disappears

Just for balance, UKMO is fine

The UKMO, although flatter than the ECM - on the basis of what I suggested in terms of margins, would still bring in something of an easterly - it is just that it has the trough sliding south further east than the ECM and therefore the boundary of the cold air is shifted further east. The GFS still looks too flat and too far east. The ECM will confirm later whether it sticks with the opposite much more amplified suggestion once more

Edited February 4, 2013 by Tamara Road

[Snowman.]

I have to admit I now have a concern, if gfs was right all along it's pulled its trump card on this run, the Northern Norway shortwave. This destroys the Westwards movement of the Russian high.

http://modeles.meteo...nh-0-132.png?12

I hope it's just thrown that in at random and it disappears

Just for balance, UKMO is fine

Going to compare to the 6z

You can clearly see that there is less energy in Greenland now this is the 12z

You can clearly see that it has spawned a little shortwave from the energy left around Greenland.

We really need to keep a eye on it as this could just screw up what we have left of winter.

[MR EXTREMES]

incredible differences with gfs and ecm and the gfs really does love its shortwaves and loves to blast any type of blocking away.

can the ecm do it again tonight i bloody hope so my nerves are shredded.

Edited February 4, 2013 by model rollercoaster

[Coast]

The ECM will be expected to be the model to have shown the way on this pattern - it appears to have been after seeing the UKMO 12z.

This is now following it in the broad sense.

The GFS well, shocking as usual.

But without the actual outcome of the weather being known currently (as it is a future forecast), how can we be certain that GFS is 'shocking' or the others 'good' Steve? It makes it sound like they are not showing a certain preferred scenario yet and so must be good or bad (or indifferent), surely we need to wait until the outcome has passed to judge their quality?

[Jason M]

And, if the weather doesn't perform that hoped-for 'separation'? Then what?

Then in terms of this thread, assume the crash position ie head between legs and kiss ......................

METO looks absolutely fine to me. I think people sometimes forget that the charts are for a different time frame than the last run. The differences are smaller with GFS by virtue of a run every six hours whereas ECM / METO are every 12 hours. Synoptics can change a lot in that time frame.

GFS looks poor but as always look to the ensembles at present to see if they trend one way or another.

Jason

[Snowman.]

12z is a horrible run that shortwave just had a massive roll on effect.

[swfc]

Such are the fine lines here id be wary of calling this eitherway.even the ukmo looks close to delivering nothing and that in itself shows how tight things are imo?

[MR EXTREMES]

12z is a horrible run that shortwave just had a massive roll on effect.

it almost goes southeast then shifts northeast perhaps the azores ridge is pushing it in that direction not good gfs bit of a concern.

[Captain Shortwave]

12z is a horrible run that shortwave just had a massive roll on effect.

Simply put if that shortwave verifies, it game overs this winter as the knock on effect is huge. You still get the warm air push from the pacific which pushes a reforming vortex straight over Greenland, atlantic train back in. If it doesn't you get a 2 or even 3 point attack at the Canadian vortex causing it to weaken and give us a big chance at some proper high latitude blocking.

Anyway lets be positive, UKMO still will give the goods as the ridge is well over the top of us to the north. Lets hope ECM sticks to it's consistency.

Edited February 4, 2013 by Captain shortwave

[Rollo]

Talk about model fatigue. We had a similar thing in the days leading up to the January cold spell and nothing really has changed this time,as long as one set of charts goes one way and the other another then we are pretty much in limbo.

As much as want to see the cold weather win I feel perhaps a day or two away from the charts altogether would be a good idea.

[mountain shadow]

it almost goes southeast then shifts northeast perhaps the azores ridge is pushing it in that direction not good gfs bit of a concern.

Given the pressure to the North East i find it inconceivable that the Low would move in that direction. Sheer logic dictates that the low would disrupt and move south east.

Doesn't make any sense.

[stodge]

http://www.wetterzentrale.de/pics/Rtavn1201.png

The problem isn't to our west but to our east in the form of the LP over the Baltic States. As in December, this feature stops the Russian HP ridging strongly into Scandinavia and building up the block.

http://www.wetterzentrale.de/pics/Rukm1201.gif

UKMO has the feature a shade further south and weaker and that allows a small HP cell to build up over Scandinavia and holds the Atlantic to a more NW/SE trajectory.

http://www.wetterzentrale.de/pics/Recm1201.gif

The 00Z ECM showed a weaker feature over the Baltic with the main LP further south.

I fear IF that Baltic LP is as far north and as strong as modelled by the GFS, any block will be scuppered.

[Tamara]

Such are the fine lines here id be wary of calling this eitherway.even the ukmo looks close to delivering nothing and that in itself shows how tight things are imo?

Yes it is rather tight - however the ECM up to now has backed the pattern further and further west and that gives it *some* room to adjust back eastwards without undue backtrack. Another test tonight if it will hold the pattern that far west, but as RB above rightly says, it will be the weather that decides and not us

[SMU]

But without the actual outcome of the weather being known currently (as it is a future forecast), how can we be certain that GFS is 'shocking' or the others 'good' Steve? It makes it sound like they are not showing a certain preferred scenario yet and so must be good or bad (or indifferent), surely we need to wait until the outcome has passed to judge their quality?

The reason is for calling the ECM the assumed solution is because the GFS was total Woeful last time, the GFS has an easerly bias & the GFS cannot deal with trough disruption-

So we should always assume the GFS is a lower varifying model with less chance of being correct. especially with the known bias.As said though we cannot 100% discount it .

S

Edited February 4, 2013 by Steve Murr

[Ian Brown]

HI Tim-

The ECM will be expected to be the model to have shown the way on this pattern - it appears to have been after seeing the UKMO 12z.

This is now following it in the broad sense.

The GFS well, shocking as usual.

The finer detail at 120 - 144 is up for grabs & we are at the margins on that-

UKMO is quite East at 120, & east as well at 144- where as the ECM is more west circa 300 miles.

Small model differences to be expected at day 6, & possibly more to come until T48-

however i guess you would take the middle track down the spine at this stage.

The UKMO * COULD* be right - rather like a hurricane forecast track there will be a cone of track within the ECM suite- looking at the ECM control & OP the UKMO track is EAST of the ECM MEAN & OP + CONTROL, but a plausable outcome if the jet isnt quite as amplified.

As said though the ECM looks to have nailed the overall pattern ( but we cannot pat ourselves on the back yet ) until we get full model consensus just incase the GFS solution is correct - which I would rate the chances at '2% where the low rides over the top of the scandi block.

S

We will have to see Steve, I would not favour the GFS purely from a ‘form’ point of view and it’s poor handling of similar set-ups however that does not mean that it is wrong on this occasion – and as we know – invariably if it can go wrong (especially where shortwaves are concerned) it will.

[phil nw.]

To be honest folks i find both runs disappointing from a cold pov.

I was hoping at least that the UKMO would follow it`s 00z run with the slider low moving SE across the UK but it has moved the energy more west to east on this run,

Not quite as flat and progressive as the GFS but we are talking fine margins here and any eastward shift is not good in order to have a chance of an easterly.

The 00z ECM had that little margin of error with that slider further west so it will be interesting to see if it`s 12Z output holds firm on that.

There is still time for movement either way on this but there`s that one elephant in the room that is a worry and thats the Azores High-notice he`s reluctant to leave.

[Tim Bland]

I suspect a few will be watching the ECM roll out from behind the sofa or between their fingers. Expect a backdown and then anything else is a bonus IMO. I was shot down in flames for suggesting the UKMO will be more on the money and show us the halfway house between the ECM & GFS. To my eyes it is just that

Edited February 4, 2013 by Tim Bland

[SE Blizzards]

Meanwhile the NOGAPS and the GEM both on board and back the ECM / UKMO!

http://www.meteociel...&mode=0&carte=0

http://www.meteociel...&mode=0&carte=0

Edited February 4, 2013 by SE Blizzards

[Jason M]

I suspect a few will be watching the ECM roll out from behind the sofa or between their fingers. Expect a backdown and then anything else is a bonus IMO. I was shot down in flames for suggesting the UKMO will be more on the money and show us the halfway house between the ECM & GFS. To my eyes it is just that

Yep, fair point. I personally marginally favour ECM / Steve Murr, but every GFS run that says no increases the doubts. Ensembles running out at present and within next 10 minutes will be out to day 5. Will be interesting to see and of course ECM still to come.

Jason