Stratosphere Temperature Watch 2014/2015

[johnholmes]

Couldn't have put it any better myself

The only interesting difference is the GEFS is certainly keen to keep more of the vortex energy towards the Siberian sector - a theme I would like to see repeated.

It would be interesting to see some of those WSI ECM EPS charts again today over on Twitter to see if those are still holding firm, but given the output from 12z yesterday one would suspect so.

This is probably unlikely to be the main event but once again is shows what a very different situation we are in to this time last year. Up until now (in what has already been a very successful November stratospherically) we have seen obvious signs of an improved Brewer-Dobson circulation, helping to drive ozone up in to the northern hemisphere, then of course we started seeing the fairly consistent wave 1 activity, the only thing we have been looking to join the party is wave 2....not only has he arrived, but it looks like he's bought snacks and a keg with him too

SK

 

much of what you folk write is above my old head, I take my hat off to you all, the amount of knowledge and understanding of such complex issues is absolutely stunning and not one meteorologist amongst you. I ponder what earlier this year, be it 1 month back or 6 months back, seems to be the cause (perhaps?) of the change in state of both the Stratosphere and Troposphere from the same time last year. Fascinating to read. Please keep giving these posts. As an old ex metman it is really interesting when I think of what Met research was going on 30 years ago.

[bluearmy]

John - I'm sure you meant to say ' Apart from matt '

Interesting that this upcoming activity appears to wane according to the gefs as we head through week 2. We have no idea if ECM sees it the same way.

[snowking]

John - it's certainly very interesting and the most obvious answer, based around Judah Cohen's work, is the feedbacks created by the high Snow Advance Index seen this year, giving us the stronger Siberian high, ridging in to Scandinavia, and the resulting wavelengths producing the Aleutian Low, helping to drive the wave activity seen so far, producing the much more troubled vortex than that of last year. Of course there may be some links with the OPI too (in fact given the current state of play I would say almost undoubtedly - the two seem intrinsically linked) but until we have seen the research here we cannot say with absolute certainty

BA - absolutely and I would fully expect it to. Despite the accelerated state of play at the moment I would not expect this to be 'the big one' should we say, merely just another mini attack, and no surprise of course to see the resultant moderation of the AO (and associated winter is over posts across various threads) - the next hit, however, I would think could provide a killer blow if everything goes according to plan through December...

SK

Edited November 13, 2014 by snowking

[Recretos]

As far as 2009 is concerned, we really are in a slightly different situation this year, as far as this forecasted split goes. 

 

  

 

  

 

I have to say that I am really not too happy about this current split, or at least what is forecasted to follow after it. But on the other hand, I can almost see where it is going after that (after FI), and I think I am kinda starting to understand how this whole story of the 14/15 season might look like stratospherically.  But enough speculation for now. All in its time.

 

Regards.

Edited November 13, 2014 by Recretos

[John Badrick]

As far as 2009 is concerned, we really are in a slightly different situation this year, as far as this forecasted split goes. 

 

  

 

  

 

I have to say that I am really not too happy about this current split, or at least what is forecasted to follow after it. But on the other hand, I can almost see where it is going after that (after FI), and I think I am kinda starting to understand how this whole story of the 14/15 season might look like stratospherically.  But enough speculation for now. All in its time.

 

Regards.

Hi Recretos, can you give us an idea how you think the 14/15 season will pan out? I know its speculation, but it would be good to know you're thoughts

Cheers 

JB

[picog]

 

I have to say that I am really not too happy about this current split, or at least what is forecasted to follow after it. But on the other hand, I can almost see where it is going after that (after FI), and I think I am kinda starting to understand how this whole story of the 14/15 season might look like stratospherically.  But enough speculation for now. All in its time.

 

Regards.

Now that's what I call a tease!,

[KyleHenry]

Recretos , I agree with what your saying regarding wave 2 and it is not going to do Central/NW Europe any favours regarding less rain and replaced with a more colder air mass.

There would need to be a CW event within next 14 days to push Canadian PV further into Russia.

If the MT event occurs it may just buffet the PV back over to East Canada/ Greenland.

So last third of December 2014 signalling first chance of NW Europe getting cold but no percent of probability can be given for another 14 days.

Matt Hugo has given hints that a possible repeat of 2013 Feb/ March Arctic breakout for NW Europe.

Waiting game but highly enjoyable to watch.

[Crocodile23]

Without question an impressive set of charts and the starting point for this split isn't on D10 it begins around D7/D8.

I always wanted to ask this question to understand this wonderful thread even more. Perhaps it's a trivial or silly question but nevertheless i have to ask....

 

Stratosphere, troposphere, surface doesn't matter the models have their D+1, D+2, D+8, D+9..... etc predictions with some accuracy.

 First question i have to ask is: Does the D+X prediction of a model of a stratospheric map(e.g 10 hPa heights) has more predictive skill than a D+X of a tropospheric variable like for example 500 hPa(mbar) heights?

 

Because if they have the same, then stratospheric-based forecasting has the same value as tropospheric one and has no actual advantage.

Or maybe it has anyway? Because since the stratospheric results in the space we live, low troposphere, are becoming apparent many days after(i mean a stratospheric pattern will lead to a tropospheric one some or many days later), then even IF D+6 for example has the same predictive skill for 50 hPa and 500 hPa, then forecasting(for long-range of course) via 50 hPa has the advantage to know the tropospheric synoptic end result(approximately of course) some 5-6 days after. Am i mistaken in the last conclusion?

 

Other than that, how does it really go in the aspect of stratosphere-troposphere interaction and about which "prevails"?

I.e: a certain stratospheric pattern at some time, will lead to a certain(with small probable diversities of course) synoptic tropospheric pattern. Right or this is not completely correct and it depends heavily on the tropospheric circulation also? What i mean more clearly:

 Is looking at a map of stratosphere and forecasting the evolution of the troposphere, solid enough? Or we need to see the tropospheric map also and combine the stratospheric-tropospheric maps to forecast the synoptic evolution?

 I.e: If we just look at a stratospheric map and ignore the troposphere, is there any possibility that a certain feature of the troposphere(e.g a extratropical cyclone, a surface anticyclone(that does not appear in stratospheric maps), a tropical cyclone, etc) to completely destroy our synoptic forecast and lead to a completely different synoptic result from our prediction?

 

With other words, are there sometimes features of the troposphere(like a surface low deepening too much over a warm sea) that will "lead" the stratosphere?

Long term(in months scale-climate) we know this happens with snow extent, sea ice cover, great mountain ranges like Rocky mountains and Himalayas, etc, that effect strongly the stratospheric circulation, but what about short-term(scales of days or weeks-weather)? Can a prediction of a map in the stratosphere that one says oh look this will definitely evolve this way after 10 days, be actually "destroyed" and a tropospheric event to lead the stratosphere to behave completely differently?

 

 

[radiohead]

I know it's very early days, but I'm a little concerned about some of the comments from Recretos and Chiono about the wave attack potenitally leaving us in an unfavourable position. That would be very frustrating...Keeping my fingers crossed.

[Snowy L]

I know it's very early days, but I'm a little concerned about some of the comments from Recretos and Chiono about the wave attack potenitally leaving us in an unfavourable position. That would be very frustrating...Keeping my fingers crossed.

 

Very hard to predict and they usually leave some form of residual energy in the Atlantic. 2012/13 was a classic example of this. The Atlantic was still very active following the SSW, yet even with a very weak block to our North/Northeast, we managed to see a prolonged cold spell with the block managing to undercut. As long as we get some sort of block to our NW, N or NE, we will see low pressure systems rapidly disintegrate as they approach the block, and if low pressures  do manage to push the block away, the block always has the potential to rebuild, as with 2012/13.

 

This is what we were up against during the cold spell, a very nasty looking atlantic and a very weak looking block, yet we still got a good 10 day cold spell, followed by more cold spells later:

 

http://www.wetterzentrale.de/pics/archive/2013/avn/Rtavn00120130119.png

[sebastiaan1973]

You bloomin' earlybirds!! Great to see. Difference here between 2009/10 splits is that this appears to be the angle of wave 2 attack - It may still leave a segment of vortex that is Atlantic based - leaving the UK in SWesterlies!

 

http://web.mit.edu/jlcohen/www/papers/CohenandJones_JC12.pdf

 

Well SWesterlies is just what we see 14-7 days before a SSW, according to this research by Judah Cohen. It all suits right well. High pressure in eastern Europe, low pressure near Alaska. So tropospherically  we can expect a slowly retreating Russian high to the east and  from a negative AO to a positive AO.

[MattH]

Evening all and yes John, I am a meteorologist, it took me a while, but hey persistence and hard work pays off in the end...

 

Without question I think everyone should always take note of what Ed (Chino) says in this thread, amongst others. I remember 2009, from a meteorological point of view, and always wondered how on this earth the weather could change so much, clearly back then Ed, and a few others did, I didn't and I was a meteorologist. I moved house with my family in Nov 2009 during what was one of the wettest spells of weather in Lancashire to a house that was situated at 900ft and the shock I got in December of that year, and the years that followed, was quite remarkable. Not only that I remember the spell in terms of forecasting too. The synoptics and forecasts within the medium and long range were threw into complete disarray and it was such a mess and almost hard to believe such cold and blocked patterns were coming all of sudden. So, coming back to my original point and that is if Ed doesn't think this split will aid the UK in terms of northern blocking/cold weather being the right place then I certainly believe him.

 

However, equally I would say that what we are progressing towards now is just the beginnings and this goes back to the previous page and Andrew's (Recretos') somewhat cryptic comments regards how he thinks the winter will play out, and you know what, I think I know what he is thinking. At the end of the day, compared with last winter having this kind of scenario now is better than anything we could have hoped for last winter. So, let’s say a 'lobe' of the PV ends up over Greenland and in the N Atlantic in early to mid-December and SW'lies dominate, that is still not such a bad thing when it comes to the winter as a whole and especially the stratosphere. Just because we may end up with an early split doesn't mean the vortex will end up being a 'raging beast' by mid to late January in the 'climate' that is expected 'up there' this winter. I, for one, don't give a damn really what happens initially if the vortex splits within the next 2 to 3 weeks, I'm just glad the damn thing will be on its 'knees'. Where troughs and ridges develop thereafter, within the troposphere, really is open to huge suggestion and debate and this coming (perhaps) in early to mid-December, let alone in the final few weeks of winter.

 

Step by step, let's get things going first. Keep the consistent signal going for the split, get it much nearer to T+0 and let’s see what happens. I have a feeling Ed may well be right, well so be it if he is, but again there is a hell of a lot of time left thereafter to get things in the 'right place' for the UK to get some winter weather and, jeez, in my opinion, it is well overdue!...

 

Cheers. Matt.

[Hocus Pocus]

What worries me is how the Strat maybe primed for disruption throughout this coming winter but we may end up on the wrong side of said disruption, tis a lottery I know and better to have a ticket then no ticket at all and then sit back and moan about not being a winner.

[Recretos]

Well, to reveal some of the mystery, I expect the vortex to fall at a certain time, dont get me wrong. I was staring at certain graphics and forecasts and some other stuff, literally starring, and I kinda lost myself in it, brainstorming like usually, and then it kinda hit me what might happen.

Edited November 13, 2014 by Recretos

[Snowman.]

What worries me is how the Strat maybe primed for disruption throughout this coming winter but we may end up on the wrong side of said disruption, tis a lottery I know and better to have a ticket then no ticket at all and then sit back and moan about not being a winner.

 

And I prime example in that an SSW or any form of Strat disruption doesn't all ways help us in the search for cold.

 

Glad it's like this otherwise it would make for some pretty boring weather watching.

[Hocus Pocus]

Well, to reveal some of the mystery, I expect the vortex to fall at a certain time, dont get me wrong. I was staring at certain graphics and forecasts and some other stuff, literally starring, and I kinda lost myself in it and then it kinda hit me what might happen.

That's more cryptic than your last post Recretos?

[johnholmes]

John - I'm sure you meant to say ' Apart from matt '

Interesting that this upcoming activity appears to wane according to the gefs as we head through week 2. We have no idea if ECM sees it the same way.

 

apologies to Matt

and anyone else on here who has been missed out!

[Daniel*]

Well, to reveal some of the mystery, I expect the vortex to fall at a certain time, dont get me wrong. I was staring at certain graphics and forecasts and some other stuff, literally starring, and I kinda lost myself in it and then it kinda hit me what might happen.

Hi guys nice thread you got running here, what do you mean Recretos by "I expect the vortex to fall" ?? Can you shed some light, it may seem clear to you but I'm rather puzzled.

[blizzard81]

Well, to reveal some of the mystery, I expect the vortex to fall at a certain time, dont get me wrong. I was staring at certain graphics and forecasts and some other stuff, literally starring, and I kinda lost myself in it, brainstorming like usually, and then it kinda hit me what might happen.

Cmon man! Stop being a tease and spit it out 

[MR EXTREMES]

So is this true that the wave 2 has failed ?

[Hocus Pocus]

So is this true that the wave 2 has failed ?

Not failed as such more a case of expectations of it not to deliver the goods ( for cold ) reading between the lines.

[bluearmy]

So is this true that the wave 2 has failed ?

Failed? It's hardly started yet! 'Patience grasshopper' !

[shaky]

Failed? It's hardly started yet! 'Patience grasshopper' !

when is it supposed to start! ! Cos on wsi weather they've posted a pic of a warming thats 360 hours away and saying that its more than likely gona be a fail!! Weird! It's not even started yet!! Edited November 13, 2014 by shaky

[bluearmy]

when is it supposed to start! ! Cos on wsi weather they've posted a pic of a warming thats 360 hours away and saying that its more than likely gona be a fail!! Weird! It's not even started yet!!

I suspect their point is that once it begins in earnest (in about a week), it fails to maintain the upper split through week 2. I would caution that an ensemble mean of 51 runs is the best tool to indicate a split in 14 days time.

[Mark Bayley]

A recent paper titled 'Weakening of the stratospheric polar vortex by Arctic sea-ice loss' that may be of interest. I quite like the sea ice theories, and its good to see recent papers by Cohen, Overland etc.. start to combine the effects of both increased snowfall and decreased sea ice (with links to the stratosphere, rossby waves, jet stream dynamics etc..)

 

Abstract

Successive cold winters of severely low temperatures in recent years have had critical social

and economic impacts on the mid-latitude continents in the Northern Hemisphere. Although

these cold winters are thought to be partly driven by dramatic losses of Arctic sea-ice, the

mechanism that links sea-ice loss to cold winters remains a subject of debate. Here, by

conducting observational analyses and model experiments, we show how Arctic sea-ice

loss and cold winters in extra-polar regions are dynamically connected through the polar

stratosphere. We find that decreased sea-ice cover during early winter months (November–

December), especially over the Barents–Kara seas, enhances the upward propagation of

planetary-scale waves with wavenumbers of 1 and 2, subsequently weakening the stratospheric

polar vortex in mid-winter (January–February). The weakened polar vortex

preferentially induces a negative phase of Arctic Oscillation at the surface, resulting in low

temperatures in mid-latitudes.

 

http://www.nature.com/ncomms/2014/140902/ncomms5646/full/ncomms5646.html

 

Edit: I remembered there is a topic for articles in the advanced discussion. Please move there if more appropriate

Edited November 13, 2014 by Mark Bayley