Stratosphere Temperature Watch 2013/2014

[bluearmy]

This is what we have been waiting to see -

ecmwf30f240.gif

Guess when we have seen this before?

ncep wasn't too far away on yesterday's run though the ridge to our north rather than to our northwest. And the daughter vortice not quite split off (could be different today). Tropospherically, ncep seems further east than ECM with the overall pattern so that makes sense.

re ecm's ens improvement, an extra 25 odd layers in the strat from Tuesday should be enlightening. Of course, Exeter will have had sight of the upgraded model for months and are likely using it rather than the output we see.

Edited November 17, 2013 by bluearmy

[shaky]

thank you so much for this piece of good news chino cos over in the model thread things are just so depressing at the moment.hopefully this should have an impact and a good one at that on the nwp models by showing some frigid charts.This is what we have been waiting to see -ecmwf30f240.gifGuess when we have seen this before?

[MattH]

Hi Matt we have seen splits like this prior to the early winter cold spells in both 2009 and 2010.

 

For the local trop induced wave split upwards into the lower strat is very favourable for producing significant cold in our neck of the woods.

 

Here is 2009 strat link  http://forum.netweather.tv/topic/57364-stratosphere-temperature-watch/?p=1625056

 

And 2010 (but with charts missing) http://forum.netweather.tv/topic/64621-stratosphere-temperature-watch/?p=1952060

 

We could see some interesting trop output. What a time for the ECM to upgrade its model especially wrt to strat input.

 

Ta. Must admit not sure where these years go to as I remember the 2010 thread quite well, but as usual I've slept since then!

 

Had a quick look back and as you say there certainly seems to be some similarities. As usual it'll be about the model consistencies now regarding this initial signal and whether it continues to progress nearer to present day etc. As you say the increase in model resolution from the ECMWF is timely and it'll be interesting to see, with time, whether it does create a more accurate set of data in terms of model ouput for the strat as on the Berlin site.

 

It'll certainly be interesting to see how things progress from here, as to me a lot of the up coming synoptics, in terms of a more blocked/meridional pattern, seem to have come from nowhere, with a distinctly active and zonal jet stream evident quite recently. Also just need to look at recent NAO and AO values  to see both off the scale in terms of a +ve phase. A lot of the background signals were certainly pointing towards an unsettled regime, the scenario this coming week has proven me wrong with some of my initial thoughts a week or two back.

 

Cheers, Matt.

[bluearmy]

on the subject of the ens upgrade, i assume all the data on berlin is derived from the op run. we have been shown the odd ens strat chart in the past by sebastian but any improvement in the strat profiling from the upgraded ens will likely remain locked away from our eyes ?  matt, will you have sight of the ens strat output ? 

[Interitus]

ncep wasn't too far away on yesterday's run though the ridge to our north rather than to our northwest. And the daughter vortice not quite split off (could be different today). Tropospherically, ncep seems further east than ECM with the overall pattern so that makes sense.re ecm's ens improvement, an extra 25 odd layers in the strat from Tuesday should be enlightening. Of course, Exeter will have had sight of the upgraded model for months and are likely using it rather than the output we see.

 

Both models are yesterday's, GFS 00 and ECM 12 and it appears largely to be a response to tropospheric cross-polar ridging but this doesn't appear in the same way in today's GFS 00 but is there in the ECM.

[bluearmy]

Both models are yesterday's, GFS 00 and ECM 12 and it appears largely to be a response to tropospheric cross-polar ridging but this doesn't appear in the same way in today's GFS 00 but is there in the ECM.

 

T216 on today's gfs 00z strat 30hpa does almost split the stretched vortex as per ecm but the pattern is flatter in that area and mobile with the ridge moving positively and we end up with the core of the vortex near baffin rather than siberia with the shallow upper ridge having travelled around to n russia.  

[MattH]

on the subject of the ens upgrade, i assume all the data on berlin is derived from the op run. we have been shown the odd ens strat chart in the past by sebastian but any improvement in the strat profiling from the upgraded ens will likely remain locked away from our eyes ?  matt, will you have sight of the ens strat output ? 

 

I'm afraid not. I've got full access to all the EC ENS outputs, but none of the graphics contain stratospheric charts or information on the EC site. I would presume that those charts, as someone highlighted, will be locked away for viewing behind closed doors down at Exeter.

 

Matt.

[Recretos]

~ GEFS has the model top at 2mb with 42 layers and CMC also at 2mb with 40 layers. This isn't so important in our current case, but it is important in general for upper strat. wave breaking implementation and downwelling processes.

 

Ok about the current forecast which seems to be the hot cookie at the moment. It is a pure demonstration of the trop-strat relationship, which has been mentioned quite a few times now. In this case we have the pure troposphere effect on the strat. But since there is no warming and nothing particular to go with this effect, I expect the P.V. to reform without much difficulty, which would basically mean that the strat. would not "respond" to the poking from the troposphere. To put it like that. Another thing to consider when talking about the trop-strat relationship is the scale of the polar vortex. You have to put the polar vortex into a real-scale perspective. If you could take the polar vortex and resize it to the size of your palm and keep the original proportion, it would look like a CD or even thinner. All the maps and cross-sections increase the vertical scale because otherwise it would be hard to see anything, if the original ratio would be kept in a hemisphere cross-section.  So the trop. and strat. are much more connected that it may seem from the very "high" cross sections and other products. The actual height of the polar vortex from the ground up to the stratopause is the same as the distance between London and Reading. Putting this into perspective really helps to easier understand the processes like wave breaking and mountain effects through mountain and frictional torques. 

 

Ok, I wondered off a bit there, so back to the forecast. After playing around with ensembles for stratosphere I can say that they are a decent indicator of development, but after 240h, the usual spread kicks in and averages out most of the potential dynamics. Especially with a system like the ECM EPS with 50 members. So I wouldn't worry too much if there is no access to the ECM EPS. As a "consolation prize" I will show you 50mb forecast around 240h from NAEFS, GEFS and CMC/GEM ensembles which I plotted fresh from the 17/11 00z run gribs. The ridge is already mostly averaged, but it is still early enough in the forecast range that the main idea of the wave2 pressure is kept and seen.

 

 

And the quite averaged 10mb GEFS and CMC ENS 384h forecast, but it sees the Pacific high, just like some latest operational runs. Less intense of course, because it is the ensemble mean. On the far right is the CMC control run at 384h.

 

 

Out of time for now, but I might present some latest CFSv2 strat. forecasts soon.

 

Best regards.

Edited November 17, 2013 by Recretos

[bluearmy]

Recretos, from Tuesday the ECM ens are at 91 levels up to 0.01 hpa. I think it's been running in parallel since june

[Duane S.]

A definate increase in wave 2...

 

 

It would be nice to see it hit around the 700+ mark, this would help split the vortex as opposed to possibly only 'disrupting' it. That said, anything that administers pressure on a growing vortex can only be a good thing.

 

And one thing I have noticed with wave forecasts is more often they seem to be under estimated as opposed to over

 

 

[Recretos]

Recretos, from Tuesday the ECM ens are at 91 levels up to 0.01 hpa. I think it's been running in parallel since june

 

Yes, I missed this one, because it was not implemented yet. 14 levels above 5mb is a good upgrade. The testing was since June, but looking at the score card, it is actually worse than the current cycle in the lower strat. Too bad they don't have the mid and upper strat. test scores. I guess that I better remove my critique from the post above.

Edited November 17, 2013 by Recretos

[Snowman.]

This is what we have been waiting to see -

 

ecmwf30f240.gif

 

Guess when we have seen this before?

Is that also early signs of a warming up North?

[feb1991blizzard]

This is what we have been waiting to see -

 

ecmwf30f240.gif

 

Guess when we have seen this before?

 

 

GFS 12z 240 shows it starting to elongate.

 

 

 

And although a sort of re-phasing occurs, the temps towards the end are looking interesting, by the way, when did we see this before?

 

[The Northern Ramper]

GFS 12z 240 shows it starting to elongate.

 

 

 

And although a sort of re-phasing occurs, the temps towards the end are looking interesting, by the way, when did we see this before?

 

2009/2010

[bluearmy]

looking through the strat forecast from yesterdays 12z run, i note that zonal winds go from 30m/s at 30hpa down to 20m/s by day 10. the 30 m/s speed retreating up to 10 hpa. both at 60/70 N.  this is a marked change from the previous day.

 

i am also surprised to see the main wave activity (1 and 2) downwelling from the top of the strat. i thought the recent activity was all trop led and upwelling.  the major point here being that the ecm ens we see has 5hpa as its ceiling. it wont see the waves coming down from above. that will of course change come tuesday evenings run.  mind you, exeter are probably using the new output now and i didnt see anything in their updates to day that reflected anything happening over the next month - infact, they were headed into the 'back to average' camp.

[UV-RAY]

looking through the strat forecast from yesterdays 12z run, i note that zonal winds go from 30m/s at 30hpa down to 20m/s by day 10. the 30 m/s speed retreating up to 10 hpa. both at 60/70 N. this is a marked change from the previous day.i am also surprised to see the main wave activity (1 and 2) downwelling from the top of the strat. i thought the recent activity was all trop led and upwelling. the major point here being that the ecm ens we see has 5hpa as its ceiling. it wont see the waves coming down from above. that will of course change come tuesday evenings run. mind you, exeter are probably using the new output now and i didnt see anything in their updates to day that reflected anything happening over the next month - infact, they were headed into the 'back to average' camp.

On the flip side of that though they were late in calling the upcoming cold spell, so maybe they are playing it safe for now. Edited November 17, 2013 by Sceptical Inquirer

[chionomaniac]

looking through the strat forecast from yesterdays 12z run, i note that zonal winds go from 30m/s at 30hpa down to 20m/s by day 10. the 30 m/s speed retreating up to 10 hpa. both at 60/70 N.  this is a marked change from the previous day.

 

i am also surprised to see the main wave activity (1 and 2) downwelling from the top of the strat. i thought the recent activity was all trop led and upwelling.  the major point here being that the ecm ens we see has 5hpa as its ceiling. it wont see the waves coming down from above. that will of course change come tuesday evenings run.  mind you, exeter are probably using the new output now and i didnt see anything in their updates to day that reflected anything happening over the next month - infact, they were headed into the 'back to average' camp.

If a wave pushes up from the trop, Nick, where is it most likely to be felt? Rather like the energy from an undersea earthquake being felt when and where the tsunami hits land - not just at its epicentre.

Edited November 17, 2013 by chionomaniac

[bluearmy]

If a wave pushes up from the trop, Nick, where is it most likely to be felt? Rather like the energy from an undersea earthquake being felt when and where the tsunami hits land - not just at its epicentre.

 

i understand this ed but i dont see it upwelling through the strat at all. the energy appears at the very top and then works down. if i saw it headed up gently and then appearing  with more gusto higher up then i would understand better. 

[Recretos]

Speaking of heights and waves, I have managed to plot a 3D geopotential height. Its just a random GFS forecast, only to show how the heights look in 3D. The vertical scale is obviously not proportional with the real one. Just so you can get the feel of the "fluid" dynamics with the P.V. 
 

The levels from top down are: 10mb, 30mb, 70mb, 250mb and 500mb. The right image is a look from bottom up. The "valleys" are lower heights associated with troughs and cyclones and the polar vortex up in the strat, while the "mountains" are ridges and anticyclones (higher heights). Pretty basic stuff to understand.

 

And the same system, only the CFS and this time for the 27.11 around that wave 2 period. Levels from top down: 5mb, 10mb, 30mb, 70mb, 300mb and 500mb.

 

 

I will try to make some animations in the future, which might look really interesting.

 

I'm just trying to model the polar vortex as good as possible this season, as we head into more interesting times, and of course to help present the perspective and the real "feel" of the vortex and its influence. And also to support all the great analyses here in this awesome thread (for which I have a real lack of time lately) and trying to take them up to the next level. (no pun intended )

 

Netweather.tv dominating the stratosphere scene. 

 

EDIT: Added a 30mb height animation from GFS, with nicely seen pressure on the vortex and the reformation, and the new waves pressuring in the last time periods, as also seen on the 2D version:

 

8.mov

 

Edited November 17, 2013 by Recretos

[MattH]

Still looking good given yesterday's 12Z ECM:

 

Evidence of a split there from 192hrs now;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf30f192.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf30f216.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf30f240.gif

 

Split evident even all the way up to 10hPa as well, which seems quite noteworthy;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwf10f240.gif

 

Wave 2 conditions continue to increase;

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ha2_f240.gif

 

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ta2_f192.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ta2_f216.gif

http://users.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ta2_f240.gif

 

Need the consistency, but obviously just like any model, it is just that a forecast model, so whether nearer to the time these signs and signal will wane, who knows. But clearly we are getting some consistency now from the ECM model. Obvious question is; if these signs come to fruition will they actually have an impact, as per 2009/2010 or anything remotely like those years in terms of synoptics(?)

 

Regards, Matt.

[bluearmy]

Zonal winds take that hit again. I would be very interested to see the strat data with a less amplified trop run.

[Severe Siberian icy blast]

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

Very good link for data right down to 1hPa , clearly see the wave 2 activity. Along with a split vortex right down past 10hPa .

Edited November 18, 2013 by Severe Siberian icy blast

[lorenzo]

Wave 2 definitely the place to watch just now..

 

 

Something looks like happening on the 10hPa run, only one way for that pulse to go surely.

 

 

CFS still all over that Aleutian high with strong anomalies out into weeks 3 and 4, perhaps continuing to pressure what will be a split vortex with further displacement.

 

The vorticity chart out at 216 displays the separated vortex and also some fragments left in a 'traffic jam' over Greenland.

 

Intriguing to see Weds. morning strat plots, wonder if any marked difference with the upgrades going live.

 

GFS today and out to 192.

 

 

[Catacol]

 

 

CFS still all over that Aleutian high with strong anomalies out into weeks 3 and 4,

gfs_t30mb_globe_1.pnggfs_t30mb_globe_65.png

 

Heights over the aleutians have been the feature of the season so far for me. Constantly rebuilding and then ridging into the arctic, helping maintain the meridional flow and clearly also putting pressure on the strat.

 

I'm still very hazy on a "November Warming" definition. How big a hit would this wave 2 activity need to make, and how much of the vortex would need to shift to siberia, in order for it to reach that classification?

[lorenzo]

Lookng at the definition here http://www.atmosp.physics.utoronto.ca/SPARC/News15/15_Labitzke.html , For me this doesn't help take it from vague to easy to identify, will attempt an analysis, but could do with some expert input here. 

 

Looking at the re-analysis for November to date at 50mb and comparing to the analog years for recorded CW's you are looking at two completely different plots for the half way point of the month, surely would need to be a massive change to offset the profile for November so far this year.

 

November 1st -15th.

 

Analogs

 

Also, from the Labitzke page there is this, indicating a change in atmospheric 'mode', are we in a new period where the poleward translation of the Aleutian high for whatever reason is in itself an anomaly now?

• [*]At the same time, the Canadian Warmings which in November/December took place in 18 of the 31 years until 1981/82, are missing during the last 18 winters, except for 2 cases.
  

Am happy to look at things and say, yep that's a Minor Warming event, rather than get further confused !

 

• [*]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.