Stratosphere Temperature Watch 2014/2015

[bluearmy]

If the warnings end up like that what impacts does this have on the UK?

 

too early to say mark. its an anomoly chart so impossible to deduce actual mean temp at 10 hpa.  will it just lead to a displaced upper vortex, weaken it so that we dont require strong wave 2 to split or just weaken the upper zonal flow to allow trop forcing to dictate an amplified slower jet

[SMU]

HI BA

 

If you take the long term Eurasion December Mean

 

  the average is around -50 to -55c across the anomaly region

 

& the anomaly is around +25c---- so look for temps hitting anywhere above -25c....

 

S

[summer blizzard]

What amplitude do you need to be classed as a wave?

 

Looks to me as if the models are showing a wave 2/3 pattern.

[Snowy L]

Interesting 18z, with a proper Greenland High established, the stratosphere charts are going for Atlantic based warming in 2 weeks.

 

http://modeles.meteociel.fr/modeles/gfs/runs/2014121718/gfsnh-10-384.png?18

Edited December 17, 2014 by Snowy L

[EML Network]

Only one run and the very final frame, but to me this looks like the beginning of a proper SSW that makes it right down to the ''right'' level, accompanied by a split vortex. 

 

This is the only chart I really look at to be fair as I don't have the time available to me to look at or understand the many other charts,  so if I am wrong please delete this post or correct me. 

 

I'd really like to see this firming up in future runs and for the warming to cut right into the heart of the pole with some yellows getting right into the center, but it looks to me as if this idea is something that has been toyed with for a while with glancing blows , could thiis be the knock out blow ?

 

Surely a SSW in early Jan is ideal for a Winter SSW, with any effects coming in the 20-30 th Jan timeframe and lasting throughout Feb ??

 

[MattH]

Yes, yes and yes to the above post...

 

The GFS, amongst other models that Recretos has posted in the last week or more have really picked up on the warming well for the 20th, if you remember, at the beginning of December and that is now occuring nicely, as evident on the variety of charts from the ECMWF site. Clearly the re-development of a strong wave 1 attack is a step in the right direction, but the much needed wave 2 or perhaps even wave 3 developments are still required but that is exactly what the GFS seems to be picking up on now.

 

Definitely a case for Andrew (Recretos) to fire up his "model-machine" to see what is evident on a more comprehensive scale towards the end of the month. However, the development or expected development of the blocking pattern across the N Atlantic over Christmas, combined with up-stream conditions in the Pacific and the USA could well lead to a sig mountain torque event and as a result increase the threat of wave 2 and perhaps wave 3 developments, hence why I believe anyway the GFS is signalling a split by the start of the New Year.

 

The end is nigh for the vortex, again in my opinion. We awaited the present warming from wave 1 activity and that has arrived and now it's time to hopefully wait for wave 2 activity due to the developments within the troposphere over the Christmas period.

 

Time to beat the vortex down good and proper in the next 2 to 3 weeks and let the 'fun and games' commence thereafter...

 

Matt.

[Paul123]

I am new on this forum and don't understand much about stratospheric warmings and how they are induced. There are many questions that still remain, after reading many of the posts in this thread over the recent weeks. 

 

This is one I would very much like to have answered. The warming at the upper level of the stratospere, say 10 hpa or higher, is it induced by the building of a tropospheric Siberian High, in the coming days? In other words: does the troposphere have a direct impact on the upper stratosphere or is the overlap merely a coincidence?

 

 

Edited December 18, 2014 by Paul123

[chionomaniac]

I am new on this forum and don't understand much about stratospheric warmings and how they are induced. There are many questions that still remain, after reading many of the posts in this thread over the recent weeks. 

 

This is one I would very much like to have answered. The warming at the upper level of the stratospere, say 10 hpa or higher, is it induced by the building of a tropospheric Siberian High, in the coming days? In other words: does the troposphere have a direct impact on the upper stratosphere or is the overlap merely a coincidence?

 

10 hpa T.JPG

 

Stratosphere question.JPG

Of course it does - but unfortunately can't answer in a sentence though will try! Through wave activity and fluxes in essence.

[Severe Siberian icy blast]

Yes, yes and yes to the above post...

 

The GFS, amongst other models that Recretos has posted in the last week or more have really picked up on the warming well for the 20th, if you remember, at the beginning of December and that is now occuring nicely, as evident on the variety of charts from the ECMWF site. Clearly the re-development of a strong wave 1 attack is a step in the right direction, but the much needed wave 2 or perhaps even wave 3 developments are still required but that is exactly what the GFS seems to be picking up on now.

 

Definitely a case for Andrew (Recretos) to fire up his "model-machine" to see what is evident on a more comprehensive scale towards the end of the month. However, the development or expected development of the blocking pattern across the N Atlantic over Christmas, combined with up-stream conditions in the Pacific and the USA could well lead to a sig mountain torque event and as a result increase the threat of wave 2 and perhaps wave 3 developments, hence why I believe anyway the GFS is signalling a split by the start of the New Year.

 

The end is nigh for the vortex, again in my opinion. We awaited the present warming from wave 1 activity and that has arrived and now it's time to hopefully wait for wave 2 activity due to the developments within the troposphere over the Christmas period.

 

Time to beat the vortex down good and proper in the next 2 to 3 weeks and let the 'fun and games' commence thereafter...

 

Matt.

Hi Matt , Im now thinking that your first prediction of the SSW of 7th jan may actually be on the money ?! How ironic that would be , I think so much attention has gone into what was happening out east , we may of took our eyes off the developments upstream ? I think the low pressure annomalies over Asia during December really took everyone by surprise , which has had a knock on effect re wave activity , but I think the damage was already done during October and November , which really prevented the vortex in developing to its full .

Its ironic that this next development looks like been trop led , mainly from the -PDO really .

So really just wondering like I said at start of post , is it realistic to look at a poss SSW during the first 10 days of jan ? But obviously with us looking northwest rather than North East ?

[snowking]

ECM Ens mean now hinting at potential split at 50mb in a couple of weeks time:

SK

[picog]

ECM Ens mean now hinting at potential split at 50mb in a couple of weeks time:

image.jpg

SK

Is the split represented by the two green areas either side of the pole?

[Hocus Pocus]

Apparently WSI have tweeted of a significant EuroAsia SSW within the next two weeks, can't post the link sorry on my iPhone at this moment in time.

[seaside 60]

Apparently WSI have tweeted of a significant EuroAsia SSW within the next two weeks, can't post the link sorry on my iPhone at this moment in time.

If this happens what does that potentially mean for us.

[Recretos]

Is the split represented by the two green areas either side of the pole?

 

That would be the temperature waves. What we usually refer to as a split, is based on geopotential heights. In this case it is not really a split on that graphic, but since it is an ensemble mean, it can be interpreted as an indication of it somewhere down the line, or around that time once it gets closer and if it keeps the same idea and once the ensemble spread reduces and the picture crystallizes. 

This particular Atlantic secondary height wave is not resulting because of the Eurasian temperature wave as WSI is saying, but it is tropospherically driven. As I said in my mysterious posts quite a while back, I was expecting the Atlantic wave 2 to emerge eventually, tho I have to admit I was expecting it a little bit sooner. But oh well, as long as its at least in the forecast for now.

[Paul123]

I wouldnt worry over it too much for now.

 

Since this thread is the best around for the stratosphere, I cant help myself not to post 3D animations of 4 SSWs that I have made. This layout includes: 3D is the isosurface of a certain temperature (written on the bottom, usually -45C), the bottom level is 150mb geopotential height, and the middle layer is 30mb geopotential height. This is layout version 1. In the version 1.2 I will include the heart of the vortex. But lets leave that for another time.

It is nicely seen how over the Atlantic, downward warmings really "ignite" tropospheric ridging with some delay, and how it cuts into the troposphere.

 

I made the layout as a preset, so once I tweak it, I can just put in any data, and simulate any SSW since 1950s, or as far as the datasets go.

https://db.tt/lZ0gAOWD

https://db.tt/co8AorvK

https://db.tt/t5PZ9bO2

https://db.tt/y3BvBQSL

 

And some other graphics I made today. Usually everything can be found on twitter where I stared posting a bit more recently. 

 

  

 

 

 

Regards

 

 

Looks as if this stratospheric warming from your 9 december post is going to affect the tropospere within the foreseeable future, particularly over Northern America. Less vorticity and more blocking in the coming week. (please correct me if I am wrong)

 

 

[thank you chionominiac for answering my previous question]

 

[Ruben Amsterdam]

This particular Atlantic secondary height wave is not resulting because of the Eurasian temperature wave as WSI is saying, but it is tropospherically driven.

 

And I think this is why we should not jump into any conclusions about any potential SSWs. We know how reliable tropospheric Greenland blocks are in FI.....

[chionomaniac]

And I think this is why we should not jump into any conclusions about any potential SSWs. We know how reliable tropospheric Greenland blocks are in FI.....

With tropospheric driven wave 2 activity, it will take some to get a SSW. I know that there is a lot of chatter tonight on twitter regarding some fantastic ensemble strat means from day 10 that are showing a split. Brilliant news, because if they verify it is very likely that we will see a great block develop to our northwest along the line of the split, and, from what I have seen the -ve NAO would not be west based like tonights ECM op.

 

In January 2009 we saw a large strat warming that led to a split SSW - but that event was a downwelling split powered from the top of the strat.

 

What we much prefer to see are the upwelling wave 2 split that tend to occur following a previous ( normally wave 1 attack) warming of the vortex, and (without being able to see the restricted charts) that appears to be what is being forecast here. This type of scenario occurred with the weakened vortices of early winter 2009/10 and 2010/2011 and these wave 2 splits are without doubt the better for more guaranteable cold. If these forecasts of the wave 2 splits verify, then we could once again be on the cusp of some special winter synoptics.

[Ruben Amsterdam]

With tropospheric driven wave 2 activity, it will take some to get a SSW. I know that there is a lot of chatter tonight on twitter regarding some fantastic ensemble strat means from day 10 that are showing a split. Brilliant news, because if they verify it is very likely that we will see a great block develop to our northwest along the line of the split, and, from what I have seen the -ve NAO would not be west based like tonights ECM op.

 

In January 2009 we saw a large strat warming that led to a split SSW - but that event was a downwelling split powered from the top of the strat.

 

What we much prefer to see are the upwelling wave 2 split that tend to occur following a previous ( normally wave 1 attack) warming of the vortex, and (without being able to see the restricted charts) that appears to be what is being forecast here. This type of scenario occurred with the weakened vortices of early winter 2009/10 and 2010/2011 and these wave 2 splits are without doubt the better for more guaranteable cold. If these forecasts of the wave 2 splits verify, then we could once again be on the cusp of some special winter synoptics.

 

Yes, you are very right. Wave 2 is what we need. But I'm just playing devils advocate here. In case that wave-2 warming is trop. based (i.e. Greenland high), it is only as certain as the tropospheric output is. And we all know that the operational models do not perform well in these situations. Early december 2013 (edit: 2012!) springs to mind. I think in these cases extreme caustion is required re. any tropospherically induced strat. splits. 

Edited December 18, 2014 by Ruben Amsterdam

[lorenzo]

With the state of the vortex due to the heavy impact of WAF during November, I think it's deceived via brief VI vortex Intensification period.

 

Simply put any Greenland block coming on the back of a strong Wave 1 will be the equivalent of throwing a hand grenade up a drainpipe.

 

For explosive results visualised, correlate the Martius and Polvani precursor blocks in the table with the Martineau animations.

 

 

http://p-martineau.com/ssw-animations/

[lorenzo]

Only out to day 10 on Berlin, if only it went out to the full FI around day 15..

 

Few temp and height plots, the 1hPa warming strong and also the temp wave at 10hPa going well, the 100hPa albeit true FI for a strat chart but highlights the background for west based NAO.

 

Vorticity shows a weak vortex and this is further underpinned by zonal wind profiling comparing now to day 10 for a reduction and tilted profile the vortex leaning with height.

 

Zonal Wind Day 1 > Day 10

 

Wave 1 drawn with a ruler today, vertical straight into the heart of the vortex

 

Finally JMA plot shows the beginning of another Wave Activity Flux attack on the vortex, note the massive activity from November, easy to see on this time series.

 

Vortex tilting and stretching and ripe again for the Wave 2 and Wave 3 attacks in later output, watch those Wave charts develop and that zonal wind plot ease up as we enter the final third of December

Edited December 19, 2014 by lorenzo

[MattH]

Hi Matt , Im now thinking that your first prediction of the SSW of 7th jan may actually be on the money ?! How ironic that would be , I think so much attention has gone into what was happening out east , we may of took our eyes off the developments upstream ? I think the low pressure annomalies over Asia during December really took everyone by surprise , which has had a knock on effect re wave activity , but I think the damage was already done during October and November , which really prevented the vortex in developing to its full .

Its ironic that this next development looks like been trop led , mainly from the -PDO really .

So really just wondering like I said at start of post , is it realistic to look at a poss SSW during the first 10 days of jan ? But obviously with us looking northwest rather than North East ?

 

Hi. Yeah, it may not be a bad estimate still the 7th, but it obviously depends on a lot of factors and I think, overall, it may well be nearer to mid-January now for an officially SSW, but we shall see. Yes, as I mentioned in a post the other day the wave 1 activity that developed through November, primarily associated with the large Siberian high pressure really weakened the vortex and in a way it was a real shame that low pressure developed over eastern areas of Siberia when it did as otherwise we could well have had a far weaker vortex by now and perhaps even a SSW by now, but hey-ho that's the stratosphere and meteorology.

 

The wave 1 activity that is coming up is looking like it'll be stronger than what occurred in November and that was pretty strong, so the vortex will no doubt weaken drastically between now and the end of December. You can tell that from how the upper level winds, especially above 5hPa go from near 70 to 80m/s down to approx 40m/s to 50m/s by the end of the month. The wave 2 activity is definitely needed though to get us to the verge of a SSW into early January, without it I don't think much will happen apart from the vortex will be made weaker but then just 'pushed around' over the N Hem in certain places. As a few have mentioned though the up coming synoptics within the troposphere certain look like they will aid the threat at least of wave 2 activity developing and I think Ed (Chino) has highlighted this before but if a bottom-up wave break can occur in and around Greenland, then you're knocking on the door of 'holy grail' kind of stuff and as what happened in 2009 or 2010, can't remember which now in which the vortex just got split right in to and we were left with a huge amount of northern blocking over Greenland and surrounding areas for weeks.

 

It's all coming together nicely now and eventually I think one will happen, estimate 7 to 14th of Jan for a SSW and with the middle and latter half of January and into February potentially producing some very, very interesting synoptics.

 

Regards, Matt.

[blizzardof96]

With tropospheric driven wave 2 activity, it will take some to get a SSW. I know that there is a lot of chatter tonight on twitter regarding some fantastic ensemble strat means from day 10 that are showing a split. Brilliant news, because if they verify it is very likely that we will see a great block develop to our northwest along the line of the split, and, from what I have seen the -ve NAO would not be west based like tonights ECM op.

 

In January 2009 we saw a large strat warming that led to a split SSW - but that event was a downwelling split powered from the top of the strat.

 

What we much prefer to see are the upwelling wave 2 split that tend to occur following a previous ( normally wave 1 attack) warming of the vortex, and (without being able to see the restricted charts) that appears to be what is being forecast here. This type of scenario occurred with the weakened vortices of early winter 2009/10 and 2010/2011 and these wave 2 splits are without doubt the better for more guaranteable cold. If these forecasts of the wave 2 splits verify, then we could once again be on the cusp of some special winter synoptics.

Hey Guys,

Quick question... what are the differences in tropospheric forcing during downwelling v.s upwelling events. Polar wave breaking/standing ridges v.s EAMT surges?

[chionomaniac]

Hey Guys,

Quick question... what are the differences in tropospheric forcing during downwelling v.s upwelling events. Polar wave breaking/standing ridges v.s EAMT surges?

Hi bo96 -I hope you are well.

 

I am not a mathematician so cannot explain in mathematical terms, but in the dynamical aspect we see - say for example in a wave 1 EAMT SSW quasi-stationary type event - the wave ride around the surf zone of the PV up to the top of the stratosphere before puncturing downwards and then possibly creating a SSW if the displacement or warming is great enough. The same type of event can occur for a wave 2 type event such as January 2009 - the vortex was ripped apart but the dynamical surf zone activity was well forecast and seen prior to the event at the top levels of the strat.

 

The other type of wave 2 events we have already seen this autumn and in previous winters band can occur early especially before the vortex has had a chance to intensify. These are less well explained as far as I can see in the literature. It appears that strat needs to be vulnerable or primed to a tropospheric wave attack and for use of a better word, this wavebreak occurs internally and upwells normally from the Greenland plateau though not exclusively but almost into the heart of the vortex rather than around the surf zone. The trigger mechanism is a deep depression running alongside a Greenland ridge which then can wave break right up to the mid strat. No real mid level strat warming occurs in the traditional route but previous warmings will have weakened the vortex to allow this to occur.

 

Without having full access to the recent strat ECM ensembles I don't know for sure, but it looks like that it is this type of wave break that is forecast days 10-15.

 

Here is an example of a tropospheric wave 2 induced pattern that led to an 'internal' split right up to 10hPa in Dec 2010 but without the classical mid or upper level strat warming and no SSW. More research needed in this area I think because I have not really heard of other mets discussing this, though Ant Masiello seems familiar of the concept when tweeting about it earlier this year.

 

 

Ed

[blizzardof96]

Hi bo96 -I hope you are well.

 

I am not a mathematician so cannot explain in mathematical terms, but in the dynamical aspect we see - say for example in a wave 1 EAMT SSW quasi-stationary type event - the wave ride around the surf zone of the PV up to the top of the stratosphere before puncturing downwards and then possibly creating a SSW if the displacement or warming is great enough. The same type of event can occur for a wave 2 type event such as January 2009 - the vortex was ripped apart but the dynamical surf zone activity was well forecast and seen prior to the event at the top levels of the strat.

 

The other type of wave 2 events we have already seen this autumn and in previous winters band can occur early especially before the vortex has had a chance to intensify. These are less well explained as far as I can see in the literature. It appears that strat needs to be vulnerable or primed to a tropospheric wave attack and for use of a better word, this wavebreak occurs internally and upwells normally from the Greenland plateau though not exclusively but almost into the heart of the vortex rather than around the surf zone. The trigger mechanism is a deep depression running alongside a Greenland ridge which then can wave break right up to the mid strat. No real mid level strat warming occurs in the traditional route but previous warmings will have weakened the vortex to allow this to occur.

 

Without having full access to the recent strat ECM ensembles I don't know for sure, but it looks like that it is this type of wave break that is forecast days 10-15.

 

Here is an example of a tropospheric wave 2 induced pattern that led to an 'internal' split right up to 10hPa in Dec 2010 but without the classical mid or upper level strat warming and no SSW. More research needed in this area I think because I have not really heard of other mets discussing this, though Ant Masiello seems familiar of the concept when tweeting about it earlier this year.

 

archivesnh-2010-12-17-0-0.png

 

Ed

Thanks so much Ed. That explanation makes a lot of sense. Because internal upwelling typically occurs after an initial wave break can penetrate the surf zone of the PV, would that type of progression be more common following wave 2 events? The 0z run of the euro ensembles are really aggressive with a transition to strong wave 2 or even wave 3 warming after day 10. This predominantly comes from the Greenland/AK blocks but the E euro high begins to become more active near D13 and this is quite a strong signal for an ensemble mean at that range. 

Edited December 19, 2014 by blizzardof96

[chionomaniac]

Thanks so much Ed. That explanation makes a lot of sense. Because internal upwelling typically occurs after an initial wave break can penetrate the surf zone of the PV, would that type of progression be more common following wave 2 events? The 0z run of the euro ensembles are really aggressive with a transition to strong wave 2 or even wave 3 warming after day 10. This predominantly comes from the Greenland/AK blocks but the E euro high begins to become more active near D13 and this is quite a strong signal for an ensemble mean at that range. 

Only ever seen an internal wave 2 splitter, so would say yes, though that is without checking historically. The internal wave split is the best type imo because it automatically reinforces the block that occurs from the wave break.