Stratosphere Temperature Watch 2014/2015

[KyleHenry]

Dr Cohen's latest thoughts

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

Colder Eastern US and Scandavia up to mid Feb, NAO struggling to move negative for foreseeable. AO neutral to slightly negative.

[Woollymummy]

I emailed the office, the outreach officer Marcia said it would be up on their website soon.

 

I was wondering if they will release a video of the presentation later.

[chionomaniac]

I emailed the office, the outreach officer Marcia said it would be up on their website soon.

Thank you - I can't wait to watch it.

[feb1991blizzard]

 

 

Another occasion when the GFS models a strong warming in FI, mutes it to something far less strong and then brings it back at the corresponding timeframe a few days later.

[chionomaniac]

 

 

Another occasion when the GFS models a strong warming in FI, mutes it to something far less strong and then brings it back at the corresponding timeframe a few days later.

It all depends on the strength of wave breaking from a preceding EAMT event. The stronger that this is modelled, the stronger the strat warming.

[feb1991blizzard]

It all depends on the strength of wave breaking from a preceding EAMT event. The stronger that this is modelled, the stronger the strat warming.

 

Is there any way of telling this, the Mountain Torque charts don't seem to have a predictive element on them, and they are always corrupted as well. Meanwhile the Ensemble mean is slightly stronger than the 12z suite, although it looks like the op is a bit of a strat outlier, Bias Corrected GEFS awaited with interest.

 

 

The upshot of the 18z FWIW is that we have a forecast reversal at the very top and a borderline one (wouldn't want to call whether its an actual one) right down to between 5-7mb

Edited January 24, 2015 by feb1991blizzard

[Weather-history]

The GFS 06Z has the polar vortex displaced over Scandinavia at the 10mb level at 384hrs and it looks under stress to my eye.

Would that be a stratospheric high?

[chionomaniac]

The GFS 06Z has the polar vortex displaced over Scandinavia at the 10mb level at 384hrs and it looks under stress to my eye.

Would that be a stratospheric high?

The stratospheric high or ridge is based over East Asia/Alaska at that time.

 

 

what we would like to see is the heat fluxed polewards along path A in the above chart rather than circling the surf zone along path B.

 

Path A weakens the vortex further whereas path B reinforces the high which will the displace the vortex to the Atlantic sector somewhat more.  Every run changes a little but it is these nuances up in the stratosphere that can eventually have a bearing on the tropospheric output. Obviously we still have the self driven tropospheric vortex to deal with anyway but a nudge in the right direction from above influences greatly.

[bluearmy]

Interesting gfs 12z strat run late on. More so higher up. Mind you, the speed with which the upcoming pattern imprints onto the trop, who knows what would transpire.

[feb1991blizzard]

Seems a different story each run but always with a severely weakened vortex.

 

[bluearmy]

Seems a different story each run but always with a severely weakened vortex.

 

 

 

i think that, given the time of year and the upcoming strat/trop coupling, the heights charts are probably more important than the temps

[bluearmy]

Interesting gfs 12z strat run late on. More so higher up. Mind you, the speed with which the upcoming pattern imprints onto the trop, who knows what would transpire.

Mid upper strat on gfs remains with the Siberian vortex troughing into Europe through week 2. It seems that the east euro trough will survive in the trop but we look to come more under the azores ridge influence. I doubt the whole story has become clear yet.

[chionomaniac]

Mid upper strat on gfs remains with the Siberian vortex troughing into Europe through week 2. It seems that the east euro trough will survive in the trop but we look to come more under the azores ridge influence. I doubt the whole story has become clear yet.

Yes - we could see the longest sustained toppler in the history of topplers with this vortex placement longevity and positioning.

[damianslaw]

Yes - we could see the longest sustained toppler in the history of topplers with this vortex placement longevity and positioning.

 

 

Would like your thoughts for possible developments come middle of February. If there is a continued signal for the central PV core heights to remain on the Canadian sector is there is a strong likelihood for heights to develop over the Siberian sector and coming over the top of the sinking euro trough, with the azores high in play, if we see a weakened PV overall could there be a link up of heights from the azores towards building heights to our NE? Some forecasts going for drier more blocked conditions may be seeing such a scenario.

 

Personally I think if we are likely to come under the influence of 'blocking heights' it is more likely to be due to the position of the azores high and how it interacts with any heights to our NE. I don't foresee heights building to the NW, but a distinct possibility of an azores-scandi high link up.

[chionomaniac]

Would like your thoughts for possible developments come middle of February. If there is a continued signal for the central PV core heights to remain on the Canadian sector is there is a strong likelihood for heights to develop over the Siberian sector and coming over the top of the sinking euro trough, with the azores high in play, if we see a weakened PV overall could there be a link up of heights from the azores towards building heights to our NE? Some forecasts going for drier more blocked conditions may be seeing such a scenario.

 

Personally I think if we are likely to come under the influence of 'blocking heights' it is more likely to be due to the position of the azores high and how it interacts with any heights to our NE. I don't foresee heights building to the NW, but a distinct possibility of an azores-scandi high link up.

The main thing is, is that the strat vortex has moved away from a central or Greenland placed position, and this is translating well with the quasi stationary wave to the troposphere. It gives us a shifted baroclinic look to the strat with the wave 1 warming that is forecasted to occur, reinforcing that displacement. It is because the displace strat vortex is holding resident over the Eurasian segment that we can think that a more northerly regime is going to exist for the foreseeable. Any attempt af a ridge build to our west that is then pushed to the east is likely to collapse back to the northerly pattern unless we see other scenarios develop - such as an increase in wave 2 activity which splits the displaced vortex, or further MJO convection which pushes the MJO to phase 8. 

 

Would say early Feb is a little too far to call presently.

[Jonan92]

It's somehow worrying for me to see that the GFS keeps making stronger the Canadian vortex segment, it's a trend that has carried on in the last runs and doesn't match the stratospheric placement of the vortex

 

Taking as an example February 3rd

 

22nd

 

 

23rd

 

 

24th

 

 

25th - Today

 

[TomDav]

I am fairly new to these charts but is latest GFS close to a reversal at 10hPa 384 hrs?

 

[chionomaniac]

I am fairly new to these charts but is latest GFS close to a reversal at 10hPa 384 hrs?

 

Yes, well spotted, here is the NW image and I reckon that we are in SSW territory there!

 

 

(But it is GFS T+384)

 

Funny enough I can see your hotlink image on my reply 

Edited January 25, 2015 by chionomaniac

[Snowy L]

Yes, well spotted, here is the NW image and I reckon that we are in SSW territory there!

 

viewimage-2.png

 

(But it is GFS T+384)

 

Funny enough I can see your hotlink image on my reply 

 

If that set up translated decently to the troposphere, what's stopping a true Greenland High forming instead of a toppler?

[chionomaniac]

If that set up translated decently to the troposphere, what's stopping a true Greenland High forming instead of a toppler?

Tropical and extra tropical tropospheric influences. It is still worth pointing out that the troposphere generates it's own primary temperature gradient induced vortex that it is difficult for the stratospheric vortex to fully override.

 

Remember there is somewhat of a battle ongoing between the cold pooling tropospheric Siberian High and the upper stratospheric vortex displacement. If we had s strong vortex split then we could expect direct tropospheric consequences but a displacement is not as easy to predict. 

[bluearmy]

ECM continues to increase the zonal flow again as the wave activity drops away.

[KyleHenry]

ECM continues to increase the zonal flow again as the wave activity drops away.

Yeah I'm seeing that too, one thing about Stratospheric activity this winter is that the waiting time for next event has been very short.

So if the GFS has what looks like a SSW for the 8th/9th Feb at 10 hPa then it's back to looking at Berlin charts from 2nd Feb onwards.

10 days now of very low solar energy output, if this continued say another 5 weeks along with SSW and natural decay of PV- March looks highly likely to be a negative CET month if displacement is favourable.

[feb1991blizzard]

Yeah I'm seeing that too, one thing about Stratospheric activity this winter is that the waiting time for next event has been very short.

So if the GFS has what looks like a SSW for the 8th/9th Feb at 10 hPa then it's back to looking at Berlin charts from 2nd Feb onwards.

10 days now of very low solar energy output, if this continued say another 5 weeks along with SSW and natural decay of PV- March looks highly likely to be a negative CET month if displacement is favourable.

 

The start of the next warming doesn't look as pronounced on the ECM, if the GFS was to verify, I would suggest hunt for the next cold spell (possibly more potent) would be already well underway before this upcoming one has ended, it looks like the GLOSEA5 isn't really seeing any SSW potential or indeed any HLB given MO 30day updated has reverted to type, I agree we could be looking at a cold March but a negative CET is a big call!!

Edited January 26, 2015 by feb1991blizzard

[KyleHenry]

The start of the next warming doesn't look as pronounced on the ECM, if the GFS was to verify, I would suggest hunt for the next cold spell (possibly more potent) would be already well underway before this upcoming one has ended, it looks like the GLOSEA5 isn't really seeing any SSW potential or indeed any HLB given MO 30day updated has reverted to type, I agree we could be looking at a cold March but a negative CET is a big call!!

True it's a big call, if only I had access to long range ECMWF or Glosea5 data. The best I've got is the climate CFS model

http://www.meteociel.fr/modeles/cfsme_cartes.php?ech=1&mode=1&carte=1&run=10

One thing I've learned this season is that the Metoffice do discuss all factors in private but only release info to public very close to the verification time ie mini SSW 28th Dec 2014. March would be outside the 30 day limit.

As I said it's all down to displacement it may not work out in March, but the spoiling factors aren't as influential.

Then again if March 2015 came in at -0.01 degrees C Below average I could claim a hollow victory, which I wouldn't do.

Edited January 26, 2015 by KyleHenry

[Weather-history]

March looks highly likely to be a negative CET month if displacement is favourable.

I assuming you mean a negative CET anomaly?

A negative CET March has never happened.