Stratosphere Temperature Watch 2013/2014

[Cloud 10]

A couple of interesting FI charts from the GFS 12z run,firstly at 30mb with the polar vortex shifting east of the N.pole...

 

 

 

...and then at 100mb with what looks like a scandi trough and ridge towards Greenland.

 

 

 

Obviously at the outer realms of FI but worth watching all the same.

[Snowy L]

A couple of interesting FI charts from the GFS 12z run,firstly at 30mb with the polar vortex shifting east of the N.pole...

 

NH_HGT_30mb_360.gif

 

 

...and then at 100mb with what looks like a scandi trough and ridge towards Greenland.

 

NH_HGT_100mb_360.gif

 

 

Obviously at the outer realms of FI but worth watching all the same.

 

 

GFS has picked up on this a lot more than the ECM models. Still too early to say but that massive enhancement of wave-2 breaking thanks to the Aleutian High was always going to have some sort of effect. It won't affect the higher strat but you would expect it to make an impact in the strat lower down. The whole idea of Canadian Warmings is that the higher strat continues to cool whereas lower down we see a warming in Canada that shifts the lower vortex east of the North Pole, as seen in those GFS charts. The fact that it's forecasting a smaller section to split away over North America ties in nicely with the fact that it's caused by wave-2 rather than wave-1.

Edited November 6, 2013 by Snowy L

[legritter]

I realy wanted to post in this thread as i find this part of meteorology very interesting .a new science which im sure in many years time will be not far off the mark IF money and time is given to our upper atmosphere .i have always thought that its all that energy and things that come from the sun is our main weather driver .not necessarily the energy that arrives at any given time but big changes that could affect things many years down the line .Sudden warmings certainly affect our upper air flow and as the years go on more calculations and more understanding of this will help with long range forecasts .i will carry on reading this thread and perhaps one day i will be able to add some charts etc ,but a big thanks to all those that make this forum thread worth reading .

[bobbydog]

maybe we should be looking at this from a slightly different perspective. Chiono has put a lot of effort into helping us learn about the stratosphere. however, we do seem to have a tendency to 'skip over' some of the facts regarding the strat and SSW's. there are many factors which affect our winters and as we have learned, the strat is a very important one. what does seem to be happening though, is that some may be taking it as THE most important factor and watching for disruption, then not seeing it in the models therefore we will struggle to get a 'decent' winter. i.e. strong vortex means winter is 'doomed'. if we read the original informative post by chiono, it states that the strat is affected by changes in the tropsphere, not the other way round and a strong vortex can be disrupted by these changes.

bearing in mind how quickly the troposphere can change, we should not be disheartened by a lack of PV disruption being shown in the models. it is these changes which affect the strat, which then tries to 'un-change' them (the dance Chiono referred to) after all, it's a relatively new science and the models (programmed by humans) can only show us what they 'think' might happen. they don't actually know!

[cooling climate]

I could quite easily see a strong vortex that is shifted off of the pole

and HLB's caused by amplification from the Pacific ridging in the

troposphere as shown lately by some of the synoptic charts.

This in turn could very well lead to stratospheric warming.

I for one do not see a zonal December.

[feb1991blizzard]

I could quite easily see a strong vortex that is shifted off of the pole

and HLB's caused by amplification from the Pacific ridging in the

troposphere as shown lately by some of the synoptic charts.

This in turn could very well lead to stratospheric warming.

I for one do not see a zonal December.

 

 

I really hope your right, I don't see a zonal Dec in the league of 2011 and do see some Northerlies but I don't see any persistent HLB's until mid Dec at least.

[Cheshire Freeze]

I could quite easily see a strong vortex that is shifted off of the pole

and HLB's caused by amplification from the Pacific ridging in the

troposphere as shown lately by some of the synoptic charts.

This in turn could very well lead to stratospheric warming.

I for one do not see a zonal December.

 

Seems like you and I are singing from the same hymn sheet cc

[bobbydog]

I could quite easily see a strong vortex that is shifted off of the pole

and HLB's caused by amplification from the Pacific ridging in the

troposphere as shown lately by some of the synoptic charts.

This in turn could very well lead to stratospheric warming.

I for one do not see a zonal December.

 

pretty much what i was trying to say above!

[Duane S.]

I could quite easily see a strong vortex that is shifted off of the pole

and HLB's caused by amplification from the Pacific ridging in the

troposphere as shown lately by some of the synoptic charts.

This in turn could very well lead to stratospheric warming.

I for one do not see a zonal December.

 

Yep, my thinking the past few days as well CC. That anomalous high pressure in question could deal us a get out of jail card and start a snowball effect leading to an early warming event in the strat and split (more likely than displaced I would assume?) vortex to follow.

 

I've only had a cursory glance over the models etc this evening & they do seem to have picked up on a new signal, the AO forecast reflects that well. I've been watching that pretty much daily and there hasn't been any signs of it heading even close to neutral let alone negative.

 

I do struggle to see anything close to Dec '10 style prolonged spell cropping up in the near future though. I feel though that even IF we could muster some decent HLB it would likely only deal a temporary blow to a PV that looks like winding itself up quite menacingly over the next 4-6 weeks (hope I'm wrong though). And anyway, better to have a strong vortex under attack than one allowed to grow unchallenged I suppose!

[Tamara]

The amplification over the Pacific is undoubtably the mechanism as far as the end of autumn/start of winter is concerned that could well create a positive feedback cycle of repeated wave breaking that side of the pole that will make the most of what at face value is an unfavourable start of winter time stratospheric profile pattern that encourages a strong upper vortex and vigourous jet stream.

 

I very much doubt that any stable definitive HLB in our section of the NH will emerge in the coming weeks up to Christmas, but there is every chance that an increasingly colder form of zonal pattern will evolve with the pattern increasingly amplified and the jet stream tilted NW-SE due to the blocking on the other side of the pole. We already see good signals for this in the model output as we approach the middle part of this month but more especially beyond.

 

We currently can see the effects of cold air being expelled out of the Canadian arctic into the continental interior and then spilling off the eastern seaboard to steepen gradients and fuel atlantic low pressure. This pattern seems to be quite a continuing feature of the coming weeks in my opinion but the amplified pattern, if sustainable, should ensure that colder interludes of weather  become more prevalent as the amplified pattern reinforces feedbacks of more wave breaking into the Canadian side of the arctic, initially, but then hopefully a slow migration of the pacific blocking in tandem with seasonal wavelengths as we get further into the winter period.

 

However, with a prevailing +QBO that fuels the spin of the polar westerlies, and thus at face value helps stabilise the polar vortex, this could well indeed take some time. On the other hand as many have already said, it is not necessarily of consequence that the upper stratosphere is cold and relatively stable as long as the troposphere/lower stratospheric profiles can repeatedly be nudged by these wave breaking mechanisms and create some warming here and thus sustain amplification in the pattern. 

 

It is this relationship which should have the much greater relevance to us at the surface, and if this trop/lower stratosphere interference from one to the other can be fed back cyclically and repeatedly then it could well mean that the coldest conditions further up in the stratosphere need not have consequence for us. Most particularly If the wave breaking sequence can be sustained to a time when wave activity the other side of the pole can be enabled to provide a warming of greater depth to be triggered and allow blocking on the Siberian side of the arctic.

 

The amplified pattern is key here to keeping the stablest upper vortex away from the Greenland area and thus allowing albedo feedback snow cover to build up over the Siberian side of the arctic - much as we saw last winter, that eventually paid large dividends in the latter part of the winter and the Spring with a classic -AO pattern.

 

It looks as if is going to be a very hard battle in at least the opening month or so of winter to create anything sustainable that will lead to any significant cold spell this side of the atlantic and a lot of further wet, windy and rather unpleasant weather may be to come. However, such an amplified pattern is a much better one to be going into the short season with than a flat classic ++AO/NAO profile, and if it can be sustained, then it becomes an increasingly potentially effective weapon to influence the greater stratospheric temperature profiles for the middle and later part of the winter, and accordingly increase the chances further beyond amplified atlantic ridges which in my humble little opinion look to be our best hope this side of the festive period .

[Interitus]

Why is all the focus upon SSW?

There has been some comment that there has been too much attention paid to the influence of the stratosphere and that the troposphere can provide circulation conducive to cold weather by itself, transforming from a zonal state to blocked.

 

However, typically the stratosphere is involved in all this, it is a coupled system throughout the winter not just averaged over the season with warming/cooling events, but on the timescale of the AO phase which cycles +ve/-ve with average duration around 10 days.

 

Put simply, anomalous Arctic tropospheric winds propagate from the surface upwards and polewards to the stratosphere which responds with a height anomaly which propagates back to the surface and southwards in a feedback loop, primarily emphasizing wavenumbers 2 and 3. Eventually this causes a reversal of wind anomaly and the cycle repeats with the alternate phase of the AO.

 

There is much more to it than that, here is a preview version of a paper describing the process in depth, read the summary if nothing else -

http://159.226.119.58/aas/fileup/PDF/2013-4-34.pdf

 

 

 

[Catacol]

Why is all the focus upon SSW?

There has been some comment that there has been too much attention paid to the influence of the stratosphere and that the troposphere can provide circulation conducive to cold weather by itself, transforming from a zonal state to blocked.

 

However, typically the stratosphere is involved in all this, it is a coupled system throughout the winter not just averaged over the season with warming/cooling events, but on the timescale of the AO phase which cycles +ve/-ve with average duration around 10 days.

 

Put simply, anomalous Arctic tropospheric winds propagate from the surface upwards and polewards to the stratosphere which responds with a height anomaly which propagates back to the surface and southwards in a feedback loop, primarily emphasizing wavenumbers 2 and 3. Eventually this causes a reversal of wind anomaly and the cycle repeats with the alternate phase of the AO.

 

There is much more to it than that, here is a preview version of a paper describing the process in depth, read the summary if nothing else -

http://159.226.119.58/aas/fileup/PDF/2013-4-34.pdf

 

So laymen like me now have to think further...! First I got my head around the idea of the Strat acting on the trop. Now it is the case that the trop impacts on the strat in the first place, and that this bounces back down to the trop creating a new set of impacts.

 

The question is... how far back down the line of chicken and egg do we go? If it is trop to strat back to trop... then what impacts on the trop in the first place??

 

Ah... it's such an intellectual jumble. :-) Thanks for the paper - I liked battling my way through it.

 

So back in the real world maybe this major pacific ridging - and it is really forecast to be quite impressive through mid November - can kick off a strat response after all. Chio - you are very quiet. Is the strength of this near-aleutian high and the wave response it may create a little bit interesting in terms of the possibility of a CW?

[feb1991blizzard]

Could anybody help me please?, there was a post on here last year listing the date and type of every SSW since strat monitoring began, I was wondering if someone would be kind enough to post it again please. Thanks in advance.

Edited November 7, 2013 by feb1991blizzard

[Gael_Force]

Could anybody help me please?, there was a post on here last year listing the date and type of every SSW since strat monitoring began, I was wondering if someone would be kind enough to post it again please. Thanks in advance.

 

There is this list -

 

http://www.geo.fu-berlin.de/en/met/ag/strat/produkte/northpole/index.html

[lorenzo]

Could anybody help me please?, there was a post on here last year listing the date and type of every SSW since strat monitoring began, I was wondering if someone would be kind enough to post it again please. Thanks in advance.

 

Could anybody help me please?, there was a post on here last year listing the date and type of every SSW since strat monitoring began, I was wondering if someone would be kind enough to post it again please. Thanks in advance.

Aside from the Berlin page, here are another couple of frequently used lists of SSW, one matching to ENSO and the other displays displacement and splits.

 

 

Couple of charts from this morning GFS 00z, peak of warming activity at 30 mb by 72 hrs before this subsides.

 

Out to t+192 at 10mb a very Cold looking compact vortex approaching -80 degrees, with 2 distinctive areas of vorticity.

Edited November 8, 2013 by lorenzo

[feb1991blizzard]

 

Could anybody help me please?, there was a post on here last year listing the date and type of every SSW since strat monitoring began, I was wondering if someone would be kind enough to post it again please. Thanks in advance.

Aside from the Berlin page, here are another couple of frequently used lists of SSW, one matching to ENSO and the other displays displacement and splits.

 

ENSO and SSW Dates Butler Polvani.PNGSSW Dates Mitchell et al.PNG

 

Couple of charts from this morning GFS 00z, peak of warming activity at 30 mb by 72 hrs before this subsides.

gfs_t30mb_globe_19.pnggfs_t30mb_globe_65.png

 

Out to t+192 at 10mb a very Cold looking compact vortex approaching -80 degrees, with 2 distinctive areas of vorticity.

gfs_t10mb_globe_65.pngpole10_nh.gif

ecmwfpv400f192.gifecmwfzm_u_f192.gifecmwfzm_u_f192.gif

 

 

 

Cheers, that's the one I was after.

[Interitus]

So laymen like me now have to think further...! First I got my head around the idea of the Strat acting on the trop. Now it is the case that the trop impacts on the strat in the first place, and that this bounces back down to the trop creating a new set of impacts.

 

The question is... how far back down the line of chicken and egg do we go? If it is trop to strat back to trop... then what impacts on the trop in the first place??

 

 

Well of course there's always been an impact from the trop to the strat but most interactions have been looked at over longer time periods where the seasonal NAM in both layers is related but linked fairly weakly (and more weakly at the commonly used mid-strat 10mb level) apart from major events of vortex strengthening, SSW, and final warmings.

Here are two more papers to pick through in the technical teleconnections thread which further highlight immediate and short-term interactions which have a direct bearing on synoptic timescale NH tropospheric circulation - http://forum.netweather.tv/topic/73911-technical-teleconnective-papers/page-4#entry2829048

[Recretos]

I've been playing around with model grids, and somehow I managed to figure out a system, which allows me to plot NCEP model data. So the first graphic that I am going to present, will be GEFS 10mb ensemble mean, for height and temperature on the 384h period. This should be very interesting when potential SSW come into play, when I will be able to monitor how the GEFS can grab onto it. All in all, the P.V. seems to be in a fairly good shape. The minimum centre temperature is at -85°C.

 

 

The second graphic is also GEFS 10mb ensemble mean, but this time the height and the height deviation on 384 period. The maximum deviation (red areas) is around 350m, which in fact is not that much, but I am 100% sure that it has to do with the positioning of the vortex centre (different members have it shifted slightly).

 

 

 

Best regards.

Edited November 8, 2013 by Recretos

[Buriedundersnow]

if this animation works could someone plz tell me could this be the start of a Canadian warming or is it nothing

 

[lorenzo]

Not sure Buried, good question, Need Chiono to provide a clearer answer than one I can, still find the whole definition of them pretty vague to say the least..

 

Canadian Warmings often happen in early winter. They take place when the Aleutian stratospheric high intensifies and moves poleward. The Canadian warmings can reverse the meridional temperature gradient and sometimes briefly change the zonal wind direction over the polar cap, but nevertheless they do not lead to a breakdown of the cyclonic polar vortex.

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/fluxes.gif

 

 

Still the whole puzzle around these events is of interest and here are some some analogs of Canadian warming years to try and get a clearer idea.A Sunday puzzle to work through these and make some deductions...

 

 

10mb / 30mb / 50mb - November Canadian Warming Years

 

10mb / 30mb / 50mb - October Canadian Warming Years

 

 

10mb / 30mb / 50mb - October 2013

 

October 500mb Analog vs October 2013

Edited November 10, 2013 by lorenzo

[Catacol]

 

Not sure Buried, good question, Need Chiono to provide a clearer answer than one I can, still find the whole definition of them pretty vague to say the least..

 

Canadian Warmings often happen in early winter. They take place when the Aleutian stratospheric high intensifies and moves poleward. The Canadian warmings can reverse the meridional temperature gradient and sometimes briefly change the zonal wind direction over the polar cap, but nevertheless they do not lead to a breakdown of the cyclonic polar vortex.

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/fluxes.gif

fluxes.gif

 

 

Still the whole puzzle around these events is of interest and here are some some analogs of Canadian warming years to try and get a clearer idea.A Sunday puzzle to work through these and make some deductions...

 

 

 

10mb / 30mb / 50mb - November Canadian Warming Years

November Canadian Warming Analog Years 10mb.pngNovember Canadian Warming Analog Years 30 mb.pngNovember Canadian Warming Analog Years 50mb.png

 

10mb / 30mb / 50mb - October Canadian Warming Years

October Canadian Warming Analog Years 10mb.pngOctober Canadian Warming Analog Years 30mb.pngOctober Canadian Warming Analog Years 50mb.png

 

 

10mb / 30mb / 50mb - October 2013

October 2013 10mb.pngOctober 2013 30mb.pngOctober 2013 50mb.png

 

October 500mb Analog vs October 2013

October Canadian Warming Analog Years.pngOctober 2013 500mb.gif

 

 

Some similarities in the shape of those comparisons. I am also very hazy on the whole business of Canadian Warmings, but the aleutian/north pacific high is certainly modelled to be a powerul feature at the moment so maybe a warming is possible. In addition definite signs of an atlantic ridge trying to do something in the atlantic, with a trough over Eastern US... and that is a clear feature of your Oct analog chart.

 

FI I know... but the most recent GFS op once again shows the strength of the north pacific high, clearly ridging into the arctic and causing disruption to the tropospheric flow.

 

Edited November 10, 2013 by Catacol_Highlander

[sebastiaan1973]

http://www.americanwx.com/bb/index.php/topic/41639-seasonal-winter-20132014-forecast-based-on-opi-index/

OPI forecast translated by one of the founders. If I read it correctly they expect low (weak) wave 1 and wave 2. So no SSW in winter 2013/4?

 

&

 

One respons in that topic.

The November stratosphere continues to point to a strongly +AO winter. I have found a strong correlation between November east+central Asian stratosphere temperatures and the Dec-Jan AO (I would estimate R-squared of .8 or even .9 based on an ability to correctly predict the sign of the AO 9+ times out of 10).

The stratosphere over eastern+central Asia has been frigid thus far.Thus the three best tools I know of to predict the winter AO (the OPI, SAI, and Nov. Asian stratopshere temps) all point to a strongly positive AO this winter. 

Any ideas about the statement about a correlation between November east+central Asian stratosphere temperatures and the Dec-Jan AO

[Catacol]

http://www.americanwx.com/bb/index.php/topic/41639-seasonal-winter-20132014-forecast-based-on-opi-index/

OPI forecast translated by one of the founders. If I read it correctly they expect low (weak) wave 1 and wave 2. So no SSW in winter 2013/4?

 

&

 

One respons in that topic.

The November stratosphere continues to point to a strongly +AO winter. I have found a strong correlation between November east+central Asian stratosphere temperatures and the Dec-Jan AO (I would estimate R-squared of .8 or even .9 based on an ability to correctly predict the sign of the AO 9+ times out of 10).

The stratosphere over eastern+central Asia has been frigid thus far.Thus the three best tools I know of to predict the winter AO (the OPI, SAI, and Nov. Asian stratopshere temps) all point to a strongly positive AO this winter. 

Any ideas about the statement about a correlation between November east+central Asian stratosphere temperatures and the Dec-Jan AO

 

I thought the early wave 1 activity came out of a warming over Siberia? Plus Buried's animation above shows the clear pulse of some warmth over Siberia at 50 hPa at the back end of October.

 

So has it really been "frigid" there?

[Recretos]

I've been playing again with models, now that I have figured out how to plot different stuff.

 

For fun, here is the CFSv2 latest daily forecast for 10mb for Christmas. Very deep FI, so basically this is more like a test plot to show you that I will be making all kinds of model plots for stratosphere, from models of which you cant find stratospheric forecasts anywhere in the world (GEFS, NAEFS, CFS).  I also have in plan to plot cross-sections of mean(U-V-Z) flow, and other parameters on different levels. We do have the GFS basic strat forecasts and special parameters from the ECMWF control run at FU-Berlin up to 240h, but that's about it. There is no other special stratosphere modelling anywhere on the internet (like ensembles or plots beyond 384h) for the sake of diversity and to look at different perspectives when/if there will be interesting situations.

So I decided to take matters into my own hands and make individual plots for our beloved stratosphere. I am only experimenting with this, so for now I can only make individual plots, but with time I think I can figure out how to make automatic plotting. And the visual look is also pretty basic, but It is more than enough to show the main idea of the forecast. 

 

 

 

 

Best regards.

[Recretos]

I apologise for the double post, but here is CFS very deep FI with some Canadian warming for you.  10mb left, 1mb right. And yes I know very well that the CFS-Stratosphere relationship is not that perfect (tho I remember some updates being applied, but I am not sure if it was tested yet). So this is not meant to be a real forecast, but just something to show an option for early Jan. strat conditions.

 

 

Regards.

Edited November 11, 2013 by Recretos