Stratosphere Temperature Watch 2014/2015

[Snowman.]

Interesting to note.

 

Over the last few days the warmings have waned at the end of the GFS runs. However the 12z and the 6z have both masively increased the warming longevity and intensity.

 

0z

 

 

 

12z

 

[yellow snow]

EC Ens M coming in is just brutal with the warming at 10 mb. Massive ridging in the north Atlantic towards Greenland also in the trop. When do we need to see serious response further down than 10 before the lack of it starts to be worrying?

[IDO]

Dr Cohen's latest suggests after mid Jan for the SSW.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

[bluearmy]

EC Ens M coming in is just brutal with the warming at 10 mb. Massive ridging in the north Atlantic towards Greenland also in the trop. When do we need to see serious response further down than 10 before the lack of it starts to be worrying?

YS, do you have access to the strat ECM ens charts then or has something been tweeted?

[Cloud 10]

Just noticed that the NAEFS now have stratosphere charts,but not sure of resolution etc.

 

 

http://www.meteociel.fr/modeles/naefs_cartes.php?ech=240&code=1&mode=4&map=1&runpara=

[lorenzo]

Dr Cohen's latest suggests after mid Jan for the SSW.

https://www.aer.com/science-research/climate-weather/arctic-oscillation

 

Well spotted IDO, nice new avatar too. 

 

Was thinking the same Question Nick, please enlighten us Yellow Snow.

 

From the blog - the beating heart of the vortex that needs skewered by Wave 2.

[MattH]

Well spotted IDO, nice new avatar too. 

 

Was thinking the same Question Nick, please enlighten us Yellow Snow.

 

From the blog - the beating heart of the vortex that needs skewered by Wave 2.

AOBlog_20141219_Fig4-700x291.jpeg

 

Doesn't make for good reading if you ask me to be honest. Given the overal initial conditions that we started off with this winter, it would seem as though there have been and continue to be some major counter-balancing influences that, overall, are scuppering the developments really. The suggestion of a SSW in late January is definitely far later than most were thinking this winter and clearly a late January SSW may well lead to an interesting month in February but clearly we are then progressing towards late winter. Without question the majority, if not all of the forecasts issued (excluding the UKMO) were indicating a particularly -ve AO pattern through the mid and latter half of the winter and that includes Netweathers.

 

Clearly, like anything in meteorology nothing is set in stone and what surprises me about the latest discussion is the lack of emphasis on the warming and wave 1 activity that is developing now and the potential for a split, as per some models, by early January. The suggest that the AO and NAO may return to more neutral or perhaps even +ve states by mid-January is not a good thing to read to be honest.

 

As ever time will tell, but a poor update and an update that would signal a trend away from a potentially 'interesting' January in terms of cold synoptics.

 

Matt.

[bluearmy]

Berlin site running badly this morning - did notice a hint wave 2 at the top very end of the run. The upper zonal flow certainly weak for the back end of a year as the wave 1 does it's stuff. Need that wave two to split it.

[shaky]

Just 2 or 3 days ago everything was looking brilliant!! Now all off a sudden not so good for january! ! Even the models have changed drastically! ! Meto seasonal forecast could be right and we could be searching for false cold that as it gets closer dissapears!!! Really frustrating and thats me not being too dramatic! !! For me personally i nees a good old snowy spell in January at the very least otherwise its just not the same if we have it any later! ! Fingers crossed for more positive changes! !

[lorenzo]

Got to agree Matt , a very discouraging read from the Cohen blog wrt timing of any SSW, the H5 pattern not supportive of wave driving.

 

However, we do have the below quote within the blog and a recognition that the ENS from GEM and the ECM as advertised in above posts have displayed the wave 2 I think is required to get through that defensive layer in the core of the vortex.

 

Other models (notably the Canadian ensemble and ECWMF) show a more perturbed stratospheric polar vortex. Hence, the exact state of the stratospheric polar vortex is somewhat uncertain towards the end of week 2.

 

This is the first year, I think, Cohen has written a blog of this nature to reflect the SAI / SCE mechanics in action against the AO, I wonder what he thinks is the reason for the lack of ridging in NW Eurasia or 'weakness' in the standing wave pattern for the Pacific / Aleutians, as it is acknowledge the other factors creating a vortex 'conditioned' to be vulnerable to wave events remain.

 

There is, as noted some irony wrt. the Barents / Kara Sea Ice anomaly and some disconnect here with what one would expect, sea ice reportedly lower yet the vortex seemingly happy to park itself there and subdue any attempts for ridge building creating the step mode for the Siberian High to extend poleward.

 

What can we take from this then? At this stage, the Sea Ice query and the influence of West Pac Typhoons are the 2 things that I feel are mixing up the results to our detriment, need to look into this more, just thoughts and need further understanding, am beginning to think more along the lines of stronger influence of internal stratospheric vs trop control.

 

Frustrating timing aside,  there are strong signs from the ECM Ens, although that window for wave 2 is apparently fleeting and Wave 1 displace looks the more likely of results. Time will tell.

[Duane S.]

Let's play, spot the vortex...

 

Strong prolonged warming at the top level, net result, this...

 

Of course, this is all well and good but if we don't see it propogating down to the Mid Strat, yes it will help fight against any vortex reformation but ultimately could be , relatively, in vain

 

Fingers crossed we see an uptick in Wave 2 in the coming days on the Berlin plots.

[lorenzo]

There is some additional fun with wishing for the ECM to back east for colder synoptics in the immediacy, versus longer term gain and setting up W2 and W3 split, as Ed mentioned on twitter last night would prefer W2 split and it's clearly what eyes are focused on now.

 

Looking at ECM day 10, the 3 wave pattern in evidence, has GFS overplayed the vortex strength, or has ECM as per trop output suffered a dose of winter flu.

 

I wonder if Cohen builds the polar cap heights and wave activity flux plots using ECM ERA data along site EPS, although propriety to AER, what would be the ideal position as far as this work is concerned is to see an ensemble spread of GFS, GEFS, GFS P, JMA, ECM, UKMO for these projections or worked up into a similar mode to the MJO / GWO.

[feb1991blizzard]

An uptick in forecast wave 2 activity at day 10, doesn't have the look of anything definitive but perhaps worth watching maybe.

 

[bluearmy]

Assume this was the image YS was referring to (courtesy of WSI)

[BLAST FROM THE PAST]

I agree too re Cohen's update not being encouraging, having said that I'm in the average overall camp for January and not cold.  I still think that the main talk of Jan will be a SSW event.  I also mentioned in another thread how I'm surprised at the resilience of this PV, with all that was initially against it it's held its own thus far and is batting off any attempt to dismantle it.

 

 

It is correct that an SSW isn't needed for cold to smother our shores, but one thing for sure it seems that the PV needs to be 'done in' this winter for us to achieve prolonged cold.  It is still early days no doubt but the PV is riding each round at the moment

 

BFTP

Edited December 20, 2014 by BLAST FROM THE PAST

[MattH]

As per the up-coming warming, which is now short term, the GFS picked up on this at the beginning of the month and equally it is quite persistent now with regards to splitting the vortex essentially at the start of 2015...

 

Without being too specific with time frame, the images below are self explanatory and clearly could be a lot worse. The way the warming gets directly over the pole is of interest as well. Also of some significance is how the split is modelled to be present essentially throughout the whole stratosphere from around 5mb down to 100mb. There are signs that by the end of the run, just like a rubber band, it does contract once again into a single feature, but again this is signal is of worth and importance if you ask me. I wouldn't have thought that a split like this is down to just wave 1 activity and there has to be some wave 2 activity getting involved further down the line. Whether, eventually, the ECMWF charts start showing something of worth I'm not sure, but after just reading Tamara's post over on the model thread, especially regarding the GWO, then depending on the development of any blocking in the next 7 to 10 days then this certainly looks like it will have some impact as to whether we can combine the up coming significant wave 1 and then a potential wave 2 damaging blow.

 

 

Cheers, Matt.

[Snowman.]

Wave 2 showing it's face on today's 0z at 10mb

 

 

 

 

[feb1991blizzard]

Not a million miles away from a reversal right up top on the 6z, an impressive warming it looks to me.

 

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014122106&var=HGT&lev=1mb&hour=384

[bluearmy]

Not a million miles away from a reversal right up top on the 6z, an impressive warming it looks to me.

http://www.instantweathermaps.com/GFS-php/showmap-strat.php?run=2014122106&var=HGT&lev=1mb&hour=384

Looks that way but what has been notable for me is the lack of consistency on the upper strat week 2 gfs op height charts over recent days. vortex placement has drifted around, run to run. No sign of the warmings waning though. Edited December 21, 2014 by bluearmy

[ITSY]

Not sure of the precise technicality (I do my best to follow) but the 06Z looks to either displace or split the vortex towards the end of the run, with parallel warmings emerging up high to shunt the core out eastwards and vacate Greenland. Surely a positive sign?

[BLAST FROM THE PAST]

I think until we actually see the warmings splitting the vortex they'll be nothing more than what they've been upto now....forecasts.  I remain of view that mid section of Jan will see the SSW but also of the opinion it is end of Jan into Feb where we 'may' get the benefits from such an event.  Not wiping Jan out but it won't be down to any strat warming if we get sustained cold imo.  Signs are there for January sustained cold forecasts to be under severe pressure....although as mentioned by some in model thread I think we may need to look east at times.

 

BFTP

Edited December 21, 2014 by BLAST FROM THE PAST

[Tyfelin]

So to a very untrained eye, this looks like progress. According to the Berlin site today, by the 30th the warming looks like it's propagated to 30hpa:

Consequentially (I'm hoping) zonal wind speeds go from this this:

...to this:

As pointed out above, day 10 charts also hint at increased Wave 2 activity.

Please put me right if I'm being naive here,

tyfelin

[lorenzo]

Am hopeful this chart montage motivates Andrew into some coding.. slammed this together as wanted a better look from bottom up as to where each of the waves were. This prior to the 06z (P) with a rocketing Aleutian High and the split at 30hPa. A very tilted vortex which looks just now like a decent lift in wave 2 would be the equivalent of removing the wrong brick in jenga. 1hPa again looks encouraging.

 

 

GFS 240 and prior parallel, also height anomaly plot.

 

Am glad to see Mr Snow Maniac has found some snow and isn't having to bother about Cohen's doom and gloom blog and varying output, some consistency in the modelling would be good.

 

 

 

 

 

 

[Duane S.]

I think until we actually see the warmings splitting the vortex they'll be nothing more than what they've been upto now....forecasts.  I remain of view that mid section of Jan will see the SSW but also of the opinion it is end of Jan into Feb where we 'may' get the benefits from such an event.  Not wiping Jan out but it won't be down to any strat warming if we get sustained cold imo.  Signs are there for January sustained cold forecasts to be under severe pressure....although as mentioned by some in model thread I think we may need to look east at times.

 

BFTP

 

 

Way way too hasty to say that. Strat warming, albeit at the top initially, is due to start in the next few days and remain in one form or another for the forseeable future. I haven't seen anything that implies a true SSW but the only thing that has varied in the forecasts is the intensisty of the warming(s) run-to-run (up and down), other than that, from the moment it was forecast, it has dropped nicely down towards T+0.

[BLAST FROM THE PAST]

Way way too hasty to say that. Strat warming, albeit at the top initially, is due to start in the next few days and remain in one form or another for the forseeable future. I haven't seen anything that implies a true SSW but the only thing that has varied in the forecasts is the intensisty of the warming(s) run-to-run (up and down), other than that, from the moment it was forecast, it has dropped nicely down towards T+0.

That sounds good IF it has a positive effect?  Just that there were good signs weeks ago too.  Like I say not writing off Jan just whether the strat warmings are positively effecting / or will in near future.  Up til now that PV has ridden the knocks to survive pretty well 

 

regards

 

BFTP