Model Output Discussion: 12Z (02/12/12) And On...

[Ian Brown]

Matthew Hugo â€@MattHugo81

EC32 update is a cracker. It maintains N blocking throughout Dec with temps across the UK generally 1C to 3C below avg until late month.

Interesting, however is the 32 dayer any better or worse than anything else we see from the NWP ? Shouldn't we now be seeing a strong height anomaly to the South of Greenland if this had been correct 2/3 weeks ago ?

Edited December 4, 2012 by Ian Brown

[Severe Siberian icy blast]

I'm afraid the models are taking a step back , before anyone says anything, I'm not panicking , I'm simply saying what I'm seeing, gp did say a few days ago the models may look as though we are going zonal but it won't be the case .

But it's déjà vu from last wk , as in the models picked up another Atlantic push and although I'm not saying it will win, I have a feeling we may be left waiting again on this tiny island , I'm gutted to be honest, and yes things will change again, but I personally don't think come Monday we will be in an easterly, the ECM has took a big step backwards, the cold never moves forward , or at least the easterly don't, we are ALWAYS looking at charts after 168hrs.

I hope I'm wrong, can't help thinking the quote in the strat thred by a so called pro that said any blocking is to be very short lived will be found correct, just have that feeling, because its always easier for things to go wrong than right, his post was swiftly deleted .

[If Wishes made Weather]

I'm afraid the models are taking a step back , before anyone says anything, I'm not panicking , I'm simply saying what I'm seeing, gp did say a few days ago the models may look as though we are going zonal but it won't be the case .

But it's déjà vu from last wk , as in the models picked up another Atlantic push and although I'm not saying it will win, I have a feeling we may be left waiting again on this tiny island , I'm gutted to be honest, and yes things will change again, but I personally don't think come Monday we will be in an easterly, the ECM has took a big step backwards, the cold never moves forward , or at least the easterly don't, we are ALWAYS looking at charts after 168hrs.

I hope I'm wrong, can't help thinking the quote in the strat thred by a so called pro that said any blocking is to be very short lived will be found correct, just have that feeling, because its always easier for things to go wrong than right, his post was swiftly deleted .

My thoughts are similar. There is and as yet has not been any sign of deep cold and significant snow visiting our shores from the East within the reliable time frame. There have been indications that there could be, but there are equally strong indications that there may not be. The current set up, with the 0c line somewhere in the south west approaches ( and largely too marginal for low level snow) is though likely to bring us in within the suggested 1 to 3 degrees below average. But that does not mean continental conditions. Relatives in Germany at the moment expect snow constantly through and past Xmas on the charts being shown.

[Timmytour]

If we don't get a prolonged cold spell out of all this, my abiding memory will be.....

Gibby jinxed it!

[stratty]

Long timers on here have been here many times in the past!

It is either a wobble (a big one!) or as ever the fabled delivering easterly was always just that.

The interesting model watch continues...................which way will it turn over the next couple of days?

[Froze were the Days]

Agreed slight delay again in the ECM in bringing in the link up to Scandy and the evolution particularly on the GFS is more to the east and hence the real cold far to the east, a slight step backwards!

[lorenzo]

Interesting, however is the 32 dayer any better or worse than anything else we see from the NWP ? Shouldn't we now be seeing a strong height anomaly to the South of Greenland if this had been correct 2/3 weeks ago ?

It has been pretty good for the last few weeks Ian at getting the general trend correct, not to be confused with the 3 month seasonal outlook it released early November where it went for more zonality based I think largely on a ramped up Vortex at the time, this is the one yesterday GP alluded to as a 'bust'.

This update today is a peach. Puts Europe in the freezer, and the good news is temps for the UK also mirror Europe, if verified we wouldn't be missing out this time. Very encouraging for coldies.

[jessandjon]

We can't always depend on technology but never mind 06 is out soon! Like my sky dish tells me we can't get a signal which it can but it just isn't trying very hard :-)

[AWD]

The GFS ensembles actually have a respectable degree of agreement for a milder start to next week now, before the usual FI scatter sets up;

http://www.wetterzentrale.de/pics/MT8_Manchester_ens.png

In FI there are roughly an equal amount of cold members (below -5c) as there are milder members (above 0c).

[Polar Maritime]

I think people need to hold on to there hat's for a little longer, the strong signals for a blocked outlook are still there, as they have been for the past week or so, all the background signals are there, all the experienced are calling for it, and after being on this forum for 6/7 years i have never seen GP, Lorenzo, Chio and others so confident for a severe cold spell. The models are still chopping and changing, but the overall trend is still there, thats what makes model watching so interesting, we have seen so many times in the past how difficult the models deal with blocking and especially Easterly's.

Give things time to evolve, As GP said yesterday "it's coming"

Edited December 4, 2012 by Polar Maritime

[The Northern Ramper]

The ECM is consistent and that for me is the main thing to come out of this mornings runs.

[PolarWarsaw]

Poorer models today- not that I'm surprised, the interesting and real cold has never really came out of at180 timeframe and despite so relative consistency the performance at that range is probably 5%>.

It can flip easily back to cold again.

But we've been here once already so let's not be blind with faith and straw clutch remotely if/when the next runs don't show what we want.

[chris55]

Yesterdays ECM mean at 168 is pretty much identical to todays Det for the same period, so no big swings from ECM this morning.

[Rocheydub]

Sorry, but they're chalk and cheese!

[Polar Maritime]

Poorer models today- not that I'm surprised, the interesting and real cold has never really came out of at180 timeframe and despite so relative consistency the performance at that range is probably 5%>.

It can flip easily back to cold again.

But we've been here once already so let's not be blind with faith and straw clutch remotely if/when the next runs don't show what we want.

Yes as usual lot's more flipping and flopping to come from the models.. The models are not poor, it is normal for them to perform like this in these set-ups, as they take on board the background signals, which they struggle to grasp at the best of times!

Edited December 4, 2012 by Polar Maritime

[danm]

Sorry, but they're chalk and cheese!

Would be good if you could explain why. They are similar to my eyes.

Edited December 4, 2012 by danm

[Methuselah]

Nothing worth worrying about, IMHO...Just another visual representation of one possible solution to a highly-complex computational conundrum...No-one knows what shape or orientation the putative Siberian Super Block will eventually assume. Let alone all the LPs that'll surely surround it...

[Heisenberg]

Dont get hung up on one or two runs. They change, we know that, we have all seen it a thousand times. The trend is still there, the models will do what they may in the run up to it...

[Weathizard]

ECM is decent, the GFS and especially its ensembles are very poor.

However, this could just be a wobble, although equally likely is another phantom easterly.

Edited December 4, 2012 by Weathizard

[TEITS]

After reading this mornings posts I feel some are expecting too much. You will find that E,lys have always proven to be a nightmare to predict, not just in the intial set up but also the demise of the cold spell when the Atlantic tries to push in. If you're expecting every run to show -15C upper temps and a gale force E,ly then you will be disappointed. Instead just use the ensemble means as a guide.

The ensemble means continue to be excellent.

As for the GFS showing classic Atlantic Vs Scandi block and in my experience the models can get this wrong inside the reliable timeframe let alone +240. I lost count how many times in the 80's the forecasters predicted turning milder which never happened as the Atlantic failed to win.

My view of the outlook is very optimistic. At some stage the Atlantic will try to move in but this could provide snow events for the SW. During the 3rd week of Dec I feel our block to the E will move NW with any Atlantic LPs going underneath this block and at the same time the PV is going to shift E into Scandi/Siberia.

[Gustywind]

JMA and GEM poor also in terms of easterlies. Both show high pressure around or over Uk in latter output, with stronger northern arm of jet. ECM is excellent with weaker northern jet and stronger Scandi block. Which solution is right? History favours the former so on a probability basis I'd favour a cool and frosty mid December with lots of high pressure on or close to the uk.

[Catacol]

Ensemble consistency still this morning for an easterly early next week. I've given up entirely on my punt on it happening early... :-(

GEFS ensemble image for Tuesday here.

Note the signal for undercutting lows out in the atlantic. Those this morning complaining that the easterly has been shunted a little too far east should perhaps bear in mind that easterly air streams on their own are often not great news for the majority of the UK away from east facing coasts, though convective showers admittedly can bring plenty to those in favoured areas. Undercutting lows for those in the West are much more productive... so there is nothing unwintry at all about this mean chart.

This is also consistent with IanF's post a few days ago that stated the MetO high res stuff was pointing to blocking and undercut.

Finer details on the position of the block will come and go anyway - time to be patient. In the meantime snow for some tomorrow, and possibly into Thursday. Snow for some fallen already yesterday. 4 days into winter proper this is a pretty reasonable start.

[chris55]

Sorry, but they're chalk and cheese!

Remember the top one is the mean output, so although it looks "looser" the pattern is exactly the same.

[TEITS]

JMA and GEM poor also in terms of easterlies. Both show high pressure around or over Uk in latter output, with stronger northern arm of jet. ECM is excellent with weaker northern jet and stronger Scandi block. Which solution is right? History favours the former so on a probability basis I'd favour a cool and frosty mid December with lots of high pressure on or close to the uk.

GEM looks fine to me.

http://www.wetterzentrale.de/pics/Rgem1921.gif

http://www.wetterzentrale.de/pics/Rgem2401.gif

[Catacol]

After reading this mornings posts I feel some are expecting too much. You will find that E,lys have always proven to be a nightmare to predict, not just in the intial set up but also the demise of the cold spell when the Atlantic tries to push in.

Agreed, and to add to this - many on here will tell you (correctly) that the models are usually over progressive with the atlantic. Usually systems end up further west than modelled, and usually slower to arrive too. If the ensemble mean has the low pressure to our south strongest over Poland and the block just nudging out of Norway then dont be surprised if, in the final analysis, the whole pattern ends up a good deal further west. That would put us smack in the red (or should I say white?) zone.

However at this stage the fine details are just conjecture. At least we have model consistency on the overall shape of the pressure patterns, and good teleconnections. The rest needs a bit of luck...

Edited December 4, 2012 by Catacol_Highlander