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Stratosphere temperature watch - 2016/17


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I sense an issue that if we don't see the MJO activity in the Pacific and/or a La Nina-like base state (somehow) manages to enforce itself on the atmosphere - assumptions currently held by the ECM and GFS models respectively - then we'll have a distinct lack of perturbation to the lower vortex with which to ward off propagation downward of the upper vortex.

ecmwfzm_u_f192.gif ecmwfzm_u_f240.gif

The longer any 'saviour MJO' takes to arrive, the greater the risk that wave-breaking finds it hard to land decent blows to the vortex at the lower-to-mid-levels. 

Obviously we could still see wave breaking riding the intense surf zone to land some wicked blows sooner or later anyway - but then we'd be in a position of trying to recover the situation after a poor end to 2016 and start to 2017 unless of course you enjoy an overall westerly regime.

ALL_emean_phase_full.gif

The way I see this now - GEFS and UKMET show a 'maybe just about in time' version of events, while ECM is a 'you're doomed' scenario; the atmosphere could still recover an El Nino-like state but without much gusto or at least not enough when it's needed.

The major issue with trying to resolve what happens in the final two weeks of the month is that we're looking at models which explore an phase space restricted by an assumed La Nina-like tendency to the atmosphere, which as Catacol has recently been describing to great effect in the MOD thread is liable to be incorrect. Shift to a phase space constricted by an El-Nino like tendency, and the range of possible outcomes changes shape substantially and in ways that current longer-term ensemble guidance is unlikely to be sniffing out much, if at all. 

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The current projected Wave 1 displacement of the stratospheric vortex looks to be following the script nicely. During the last few days and for the next 2-3 we will see a series of unusually deep

Well this is getting interesting and a possible game changer. Why chop down a tree when you can squash a seedling ? Following the lead of the models of late last week, we have begun to tick down

The importance here I think is the consistency over the GEFS in terms of pretty much all the ENS members falling below zero and obviously indicating a wind reversal, to an extent the GFS DET can do wh

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It's worth noting that the models in the above MJO chart have differing end-points. You have to examine each one separately to have a better idea of what they're saying. One might think, for example, that UKMO goes to the 25th, whereas is doesn't- the end of its run is much closer in, and that by said date might be much more impressive.

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35 minutes ago, snowwman said:

It's worth noting that the models in the above MJO chart have differing end-points. You have to examine each one separately to have a better idea of what they're saying. One might think, for example, that UKMO goes to the 25th, whereas is doesn't- the end of its run is much closer in, and that by said date might be much more impressive.

Aye, UKMET and JMAN run to just 7 and 8 days respectively, while ECMF and GEFS both run out to 16 days.

So the first two really are being progressive with the MJO signal, GEFS a tad less so. ECMF is way off in some other dimension.

 

gfsgwo_1.png

Looking at the GWO plot this morning, GEFS seems to be starting to construct a neutral orbit, which is what's preceded the last 4 or 5 cancellations of a low-GLAAM outlook in favour of a near-neutral 'floor' and then a rise through 5/6 etc. after a week or so.

Positive developments if you're looking for a more amplified pattern to keep the lower vortex disorganised in the face of the upper one, but still some work to be done yet. Trouble is I expect an ECM version if it existed (AFAIK it doesn't, at least not in that form) would not even be trying to avoid a fall in GLAAM - hence the model's output for our part of the world has tended to be flatter in the 7-14 day range.

Edited by Singularity
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Ouch.

Pretty much just as Singularity posted above a few days ago, it is difficult to see how we pull a decent cold spell out of the hat in the next 3 weeks or so with with the emerging setup. The W-QBO playing its hand here and helps rapidly fuel the upper vortex from fledgling/growing, through susceptible and beyond into to a raging beast which then drops down through the Strat with apparent ease. We are going to need some help here.

With no significant wave breaking / warming showing up in the near future it does look at the moment as though we will need it from below. The MJO could be key as forecasts start to offer tentative signs of Pacific based activity. Nothing to get excited about yet but worth keeping an eye on in the next week or so for sure

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Can anyone find an anaolagues for such a weak autumnal start vortex becoming so strong (in zonal wins speed) so quickly ? Just wondering what might happen to it as it shows little sign of relenting high up in its attempt to mimic last years chap yet has not had the same time to mature.  Stewart mentioned some time back that word 'imposter'. is there precedent ??

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1 hour ago, bluearmy said:

Can anyone find an anaolagues for such a weak autumnal start vortex becoming so strong (in zonal wins speed) so quickly ? Just wondering what might happen to it as it shows little sign of relenting high up in its attempt to mimic last years chap yet has not had the same time to mature.  Stewart mentioned some time back that word 'imposter'. is there precedent ??

I don't really understand this graph but it seems the qbo in the lower levels did progress to easterly whereas the higher levels went back to westerly, right? So hopefully the vortex gaining strength in the higher levels won't affect our weather, at least we can hope.....

 

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/qbo/

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2 hours ago, bluearmy said:

Can anyone find an anaolagues for such a weak autumnal start vortex becoming so strong (in zonal wins speed) so quickly ? Just wondering what might happen to it as it shows little sign of relenting high up in its attempt to mimic last years chap yet has not had the same time to mature.  Stewart mentioned some time back that word 'imposter'. is there precedent ??

I believe someone mention ( cannot recall who)  that the most destructive  SSW's occur when the Vortex is at its strongest ie blows itself apart.

It would seem to make sense that if the vortex is not mature ( structurally sound) then this may lead to such an event?

The maths in the link are beyond me but the conclusion does seem to be that the structure of the vortex can lead to an SSW

 

http://www.columbia.edu/~lmp/paps/matthewman+etal-JCLIM-2009.pdf

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3 hours ago, bluearmy said:

Can anyone find an anaolagues for such a weak autumnal start vortex becoming so strong (in zonal wins speed) so quickly ? Just wondering what might happen to it as it shows little sign of relenting high up in its attempt to mimic last years chap yet has not had the same time to mature.  Stewart mentioned some time back that word 'imposter'. is there precedent ??

I'm sure they said the only time it was so weak, early on, was 2009. Lorenzo posted a good link in model thread about solar activity on strengthening of the vortex: maybe that is influencing this year, whereas the solar side was very low back in '09.

http://nora.nerc.ac.uk/501606/1/jgrd50236.pdf

Maybe we are beginning to see some effects of the cycle winding down but not enough to stop strong PV development when still in westerly QBO.

 

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irtempanim.gif

A nice convective envelope coming together over Indonesia/far-W. Pacific, while the ongoing Indian tropical cyclone journeys slowly west. 

A cooling influence on SSTs by that large convective mass associated with the TC should discourage a return of tropical convection to the Bay of Bengal and adjacent regions in the near future... right? This is why ECM puzzles me with its apparent signal for the MJO to about-face after a week of crawling only slowly east and then drift back to where it was in recent days.

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12 hours ago, bluearmy said:

Can anyone find an anaolagues for such a weak autumnal start vortex becoming so strong (in zonal wins speed) so quickly ? Just wondering what might happen to it as it shows little sign of relenting high up in its attempt to mimic last years chap yet has not had the same time to mature.  Stewart mentioned some time back that word 'imposter'. is there precedent ??

Haven't found a close anologue, but examining some of the winters in the list here:

 

https://ozonewatch.gsfc.nasa.gov/meteorology/wind_1985_MERRA2_NH.html

 

I can't find any relationship between 10hPa wind speed and direction and surface cold in the UK, even factoring- in delays, but then haven't run a comprehensite analysis. Others may conclude otherwise.

Edited by snowwman
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42 minutes ago, snowwman said:

Haven't found a close anologue, but examining some of the winters in the list here:

 

https://ozonewatch.gsfc.nasa.gov/meteorology/wind_1985_MERRA2_NH.html

 

I can't find any relationship between 10hPa wind speed and direction and surface cold in the UK, even factoring- in delays, but then haven't run a comprehensite analysis. Others may conclude otherwise.

1986 surely was a winter to remember!!!

 

https://nl.wikipedia.org/wiki/Veertiende_Elfstedentocht

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Although it's possible i'm wrong and we were just unlucky one hypothesis i'm coming to believe is that it's actually better to have a more developed vortex and get a stronger snapback than have a vortex that struggles to get going and cannot produce the huge feedback needed to cause a massive AO response. 

The fact that the vortex has strengthened (forecast to be above average) is therefore not a bad thing so long as we can a near reversal sometime soon. 

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2 hours ago, snowwman said:

And we didn't have a weak (or strong) 10hPa vortex that winter, before the very cold  February 1986.

Frequent and strong wave attacks though and a very distorted shape for a lot of the time.

archivesnh-1986-1-21-0-4.png    archivesnh-1986-2-15-0-4.png

Mouseover format for January and February 1986.

ERA interim data on Meteociel.

http://www.meteociel.fr/modeles/archives/archives.php?mode=2&month=1&day=1&year=1986&map=4&hour=0&type=era&region=nh

 

 

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GFS in the far reaches of FI does show a strengthening wave 1 attack, but this has already been downgraded from yesterday which displayed a wave 1&2 attack. I assume this due to the fact our block is loosing it's grasp a lot earlier thus we loose the wave 2. 

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Any of the more learned experts on here ready to give a update on all the telecons and what they're showing over the next few wks, month?

Thanks in advance.

Edited by joggs
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Zonal winds increase are now gradually filtering down to mid and lower levels.

We can see on the graph the upward forecasted trend and the visuals at all levels on the day 1 and day 10 to compare

fluxes.gifecmwfzm_u_a12.gifecmwfzm_u_f240.gif

so no surprise given the result of this that we have showing in the 500hPa models the now robust looking Greenland vortex.Confirmation too,as if needed,on the heat flux chart that little is happening currently to undermine the beast.

Not great news for coldies but as ever we wait in hope for signs of future wave action.

 

 

Edited by phil nw.
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5 minutes ago, phil nw. said:

Zonal winds increase are now gradually filtering down to mid and lower levels.

We can see on the graph the upward forecasted trend and the visuals at all levels on the day 1 and day 10 to compare

 

 

 

But I also see a lot more blue, darker blues in around the equator high up and some low blues creeping north and also a lot more blue up north 

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32 minutes ago, Glacier Point said:

Both GEFS and EPS going for a substantive +ve height anomaly developing in two phases at the day 5/6 and day 12-15 mark centred over Western Russia / Eastern Europe, the latter quite significant at this range. That's meat and drink to the precursor Wave 2 pattern.

Should begin to see model outputs beginning to deliver splits in the lower to mid stratosphere during the 1st week January.

 

We certainly need a big player to push us into a real wintry spell ,dont think this will come quite yet but looking at extended pressure forecasts past christmas period with a fair bit of luck we could see a cold continental feed set up .of course this could already be underway as is such the workings of the weather so coming days could give us a clue ,at the moment though it is frustrating with all this mild murky damp dross ,but many a good proper cold spell with lowland snow as materialised after similar synoptic situations that we are in now ,just a case gang that we have to be patient and watch full ,but all very interesting , and as weather is not an exact science [yet] we can only hang on tight and pray ,cheers fellow sufferers .:hi:

Edited by legritter
sorry posted in wrong forum
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As far as I see it, late Dec/early Jan is the time for the snow albedo feedbacks on the Siberian component of the high to shine, if it's going to do so with respect to our part of the hemisphere this winter; it could really help drive the wave-2 along just when we need it to undermine the furious spinning top in the stratosphere.

Some Pacific MJO activity would help with the Pacific component to the attack, right? It's just that I remain unconvinced with respect to a low-GLAAM phase setting in... though if a very weakly negative state can still assist in heights to our NE than that I can see giving us a shot at least.

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5 hours ago, Frank_Wx said:

What are the general signals to a precursor pattern? What should I be looking for?

There's no absolute one size fits all solution here as ever with complex atmospheric physics - however two of the classic signs tend to be:

 

- Large aleutian low (sometimes throwing up a Pacific ridge ahead of it) which tends to encourage Wave 1 activity

- Scandinavian/Siberian High (especially the former) which tends to set up Wave 2 attacks

As ever, that's very simplified!

SK

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On 12/14/2016 at 13:14, SN0WM4N said:

GFS in the far reaches of FI does show a strengthening wave 1 attack, but this has already been downgraded from yesterday which displayed a wave 1&2 attack. I assume this due to the fact our block is loosing it's grasp a lot earlier thus we loose the wave 2. 

Yes, the wave 1 has been low so far this month due to a notable absence of the normally present stratospheric Aleutian high as shown by the 10mb geopotential anomaly -

10anom.gif

The GFS has been flirting on and off with more normal conditions in long range for a few days such as this 10mb chart -

NH_HGT_10mb_384_17010206.gif

This and the accompanying 1mb geopotential chart show first signs of wave breaking and some long awaited baroclinity - note the slight westward tilt of the vortex with height such that the 1mb centre is rotated away from the 10mb centre -

NH_HGT_1mb_384_17010206.gif

which causes some top-down warming -

NH_TMP_1mb_384_17010206.gif

These glimpses have been fleeting so far but are most likely what is required to break down this vortex. A bit of troposphere-induced wave-2 height rise on a barotropic vortex with consequently little or no warming is unlikely to do it - GEOS forecast 10mb temperatures are forecast to reach record lows for 90°N today, 80°N by 23/12 and be 0.1 degrees off record for 60-90° average by 25/12.

But then of course a troposphere wave-2 pattern may give the surface conditions people are looking for, so they won't give a monkey's anyway.

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