Winter Model Discussion 06Z 10/01/13>

[SMU]

just for reference the GFS had only 3 euro solutions in its 00z ensemble suite-ptbs 9/11/19-

I will review & see what the 06z has.

S

Edited January 10, 2013 by Steve Murr

[TEITS]

just for reference the GFS had only 3 euro solutions in its 00z ensemble suite-ptbs 9/11/19-

I will review & see what the 06z has.

S

Just to let you know Steve the 18Z had the same number. Let me know what you find as I haven't the time this morning to trawl through the ensembles.

[EML Network]

And so the GFS has taken a baby step toward the ECM and the ECM like wsie a baby step toward the GFS.

Could we then end up UKMO which to my mind is a blend of the 2 and the end result at + 120 is rather soothing on the eye ?.and if you follow the UKMO on, I would guess that the Low Pressure out to the West at + 144 (see below) is primed to undercut resulting in something truly remarkable at lets say day 8-10 ?

Or am I clutching at straws here ?

UKMO + 120

Edited January 10, 2013 by EML Network

[Weather of Mass Disruption]

Hi Folks

A quick question from another lurker and newbie to the model thread! Would it be fair to say that if we are, as Ian F has alluded to, in an unprecedented situation, and we were to see, say a repeat of a winter like 1947, that this would be the first time our supercomputers have modeled such a situation and therefore we should expect to see discrepancies? Or should we expect better given the monies invested?

Apologies mods if this is deemed off topic!

Cracking thread, but all this info takes some digesting and getting used to, not sure if I'll ever get a complete grasp of it!

[BLAST FROM THE PAST]

IMO what IS very likely is an assault from the Atlantic in about 6-8 days time but I suggest from a southerly tracking WSW position and its going to bring possibly the most notable weather period of the winter thus far, be it heavy blustery snow or heavy blustery rain . I strongly urge no one to side with any particular model believing it to be right, there's a good chance none of them have it really right yet and I think there'll be a fewe more changes to come yet, yes we should all provide ideas of which direction we think we are going but don't be too elated or too downhearted either. Winter is really getting under way now and there's a hell of a lot of winter weather coming our way.

I can't wait to see how this all pans out, its fascinating

BFTP

[Duane S.]

The GFS is being consistant in that at T72 to T96 it takes baby, but important steps towards the other models, after this time it revert to type.

at some point maybe either tonight or tomorrow morning it will reach the tipping point where it can nolonger revert to type as the baby steps have taken it too far.

All good points made above re jet position and angle etc.

Post of the morning!

Watching through the GFS frame by frame (hardly ever do that, but in this instance it's a bit different of course) it clearly has edged towards the Euros in the crucial timeframe but not quite enough to take path 1, the tipping point was not quite reached (although I suspect it was close) and thus GFS went down path 2 thereafter.

Nothing has been decided yet and I don't hold up much of of the mid-term being agreed on for a few days yet either.

Edited January 10, 2013 by s4lancia

[nick sussex]

Good find, So really its the damn NAO that is not playing ball.

Yes that seems to be a problem.

Without that even with a PV split it will be hard going to develop sustained cold, I think theres alot of uncertainty with so many features.

The PV lobe where does it drop south upstream.

The full latitudinal trough they mention , will that occur, we certainly could do with that.

The Alaskan ridge, PNA, NOAA last night mentioned that the models want to build pressure over Greenland but that this doesn't teleconnect with the pattern in the east Pacific.

Alot of questions and as yet no clear answers.

[BLAST FROM THE PAST]

NOGAPS is not flip flopping. It's the same as the 00z. Are you denying the ECM has moved toward the GFS? It clearly has. GFS is by far the most consistent now. I am not saying no chance. If the 12z has some miraculous turn around fair enough. Right now even the most biased would acknowledge we have moved toward the GFS this morning and the GFS is most consistent and frankly at 84 hrs is most likely to be right. You disagree this. Let's see what the 12z's come up with but I really think GFS has this unfortunately.

Can you demonstrate how this is the case. Please show me and display to me how the ECM has moved towards the GFS. I must be looking at the magic roundabout then and not the ECM model.

Now whether which model is right, indeed we will see as we go along.

BFTP

[Ian Brown]

Yes, query for Ian.

Why would you be "astonished" please? The GFS is out on its own more or less without any support at all. It could be leading the way and correct, but surely using the word 'astonished' calls for an explanation. I am genuinely interested as to how and why you can hold this view.

If it's, as you've alluded to before, a simple application of percentages that the mildest option is often the correct one then, without wishing to be rude, I think that we can safely discard your opinion as it is completely unscientific. However, if there is a more logical reason, then I would be pleased to hear it so that I can re-appraise my own novice view.

Looking at the past tells us a lot about the future as all students of the formbook will tell you.

The GFS has been rock solid now for 6 consecutive runs in it’s handling of the shortwaves and the Greenland/Iceland situation. I’ve never known, after such consistency, for it do a volte face of the proportions required here.

Secondly, the ECM is gradually trending towards the GFS solution so much so that one final tilt will push the next operational run to look the same as the GFS. A significant number of the ECM ensembles now favour the GFS solution.

The theory is that in certain winters, the NAO refuses to go negative despite any number of factors appearing to suggest that it should. I believe strongly that we are seeing one of those winters.

Aside from the above, anyone who has model watched for any number of years will know that when there is such disagreement and the definite scupperer is known, it always goes wrong. The double whammy is that there would be no quick route back to another cold chance as the jet is so progressive.

[MKN]

Hi Folks

A quick question from another lurker and newbie to the model thread! Would it be fair to say that if we are, as Ian F has alluded to, in an unprecedented situation, and we were to see, say a repeat of a winter like 1947, that this would be the first time our supercomputers have modeled such a situation and therefore we should expect to see discrepancies? Or should we expect better given the monies invested?

Apologies mods if this is deemed off topic!

Cracking thread, but all this info takes some digesting and getting used to, not sure if I'll ever get a complete grasp of it!

The reason for the models seemingly being all so different is because for our tiny island what happens with the shortwave on Monday eg going east or south has a massive knock on effect to what they then go on to show. In reality which ever model is right the other models won't have been far wrong either. So anyone saying the such and such is rubbish how can it be so wrong at just +90 say when we do finally get agreement will be way off the mark.

[UV-RAY]

A quick question regarding the GFS, has it every been wrong and backtracked at such a small timescale. I'm pretty sure it hasn't and with that you have to start thinking maybe the Euros are not handling the SW as well, off course the GFS could still be wrong but I have a nagging feeling that the 06z will far nearer the mark than the ECM or UKMO.

[Duane S.]

NOGAPS is not flip flopping. It's the same as the 00z. Are you denying the ECM has moved toward the GFS? It clearly has. GFS is by far the most consistent now. I am not saying no chance. If the 12z has some miraculous turn around fair enough. Right now even the most biased would acknowledge we have moved toward the GFS this morning and the GFS is most consistent and frankly at 84 hrs is most likely to be right. You disagree this. Let's see what the 12z's come up with but I really think GFS has this unfortunately.

It won't be 'miraculous' at all. The GFS is running with a different pattern early on, that's all. Not the norm maybe but it's hardly unpresidented is it? A model consistently spews out something that contradicts the majority of the others then suddenly falls into line???? Never seen that before...

I'm not discounting the GFS by any means but I won't even be raising my eyebrows if it backtracks over the next 24 hours.

[rug]

Hi ,

Apologies if this is incorrect but apparently the NAE is following the ECM.

Can anyone shed any light on this ?

[BLAST FROM THE PAST]

A quick question regarding the GFS, has it every been wrong and backtracked at such a small timescale. I'm pretty sure it hasn't and with that you have to start thinking maybe the Euros are not handling the SW as well, off course the GFS could still be wrong but I have a nagging feeling that the 06z will far nearer the mark than the ECM or UKMO.

Yes, it backtracked massively 36 hrs ago as it was leading the way to astonishing GHP pattern

BFTP

[The Eagle]

Can you demonstrate how this is the case. Please show me and display to me how the ECM has moved towards the GFS. I must be looking at the magic roundabout then and not the ECM model.

Now whether which model is right, indeed we will see as we go along.

BFTP

Between 72 and 96 the jet profile has changed allbeit not dramatically but enough to push the trough south east of GL east instead of ESE at that stage as had been progged yesterday. That's undeniable. ECM goes back a long with it between 96 and 120 but it is the model backtracking not the GFS. And with another model now backing that consistency it's not going the right way. We may as well acknowledge that.

[Wayneywoo]

All models that are able to show data for T+72 here > http://www.meteociel.fr/cartes_obs/comp_panel.php?mode=0&ech=96&size=2

GFS is on it's own...

[alexisj9]

That is one big winter storm this GFS has coming. That big low did try to drop south east IMO but was held back by it's size, the gap in the jet was to small.

[Paul]

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[LomondSnowstorm]

I'm not convinced the GFS has been any more consistent than any other model. The ECM has shown blocking developing around east Greenlan-Iceland since the 12Z on Tuesday while the GFS only flipped to its current solution yesterday morning, and every run since then seems to bring the shortwave yet further southeast and heights that bit further northwest. The GFS generally doesn't just flip back once it moves from the model consensus but instead edges closer run by run to the euros. The euros, in spite of what people may say, are not currently backing down at all, and the ECM ensembles continue to support its own operational rather than the GFS.

Nonetheless, I still wouldn't like to bet on which outcome is closer to the truth: the GFS has a history of getting the crucial details right against the other models, but also a history of being embarrassingly wrong at short time frames. Given the NAM has been steadfast in supporting a more 'euro' upstream pattern I would certainly tend to think the euros are closer to the truth but time will tell.

[mcweather]

Post of the morning!

Watching through the GFS frame by frame (hardly ever do that, but in this instance it's a bit different of course) it clearly has edged towards the Euros in the crucial timeframe but not quite enough to take path 1, the tipping point was not quite reached (although I suspect it was close) and thus GFS went down path 2 thereafter.

Nothing has been decided yet and I don't hold up much of of the mid-term being agreed on for a few days yet either.

Agree with you there S4L, whilst there has been a lot of silly talk about the ECM moving towards the GFS solution( which as BFTP points out it hasn't done. In fact in the realiable time frame the GFS 06z has taken a small step towards the ECM. If this trend continues it will completely alter the pattern beyond.

As GP also pointed out earlier probabaly another 24 hours before final resolution on this .

[UV-RAY]

Yes, it backtracked massively 36 hrs ago as it was leading the way to astonishing GHP pattern

BFTP

Ha ha, you know what I mean Fred, the GFS is still handling the SW completely different to the Euros. This results in a totally different set up down the line IMO.

[Troubleatmill]

The 06z shows just how close this is, the shortwave coming out of Iceland only needs to Touch the low sitting over france and it will head south east and stop the link up of the Scandi High and the Azores ridge, if the latter happens its game over and the atlantic will simply ride over the top, if the fore happens pressure remains high to our north and we keep eastelies, to my eyes and this chart there is about 100 miles in it.....

Edited January 10, 2013 by Nick JB

[Bobby]

Finally into the high-res output for Saturday's snow, NMM shows snow moving into parts of SW England, Wales and Midlands. I think there's a good chance that some will get a covering from this.

Edited January 10, 2013 by Bobby

[johnholmes]

a review of the upper air predictions and actuals over the past 3 days or so. What does it tell us, what will the upper air pattern be like in a week to 10 days time?

500mb charts-a summary past 3 days on thur 10 jan12.pdf

[Mac_SE]

The broader picture - cold, milder interlude (perhaps), cold again - still seems to be resolutely line with what was suggested earlier this week by IanF, so not sure what the major panic is every time a model shows a flip to the mild side after the cold weekend.