Stratosphere Temperature Watch 2012/2013

[lorenzo]

Thanks for the update Shuttler, great to get the ECM Ens insight to compare along with the GFS data.

[bluearmy]

And no doubt the reason for no sign of any caveats on the meto extended re possible consequences of a strat warming. remember last jan where they began mentioning the possibility of cold end jan/early feb with nothing showing in the nwp and thereafter they attributed this to the upcoming strat warming forecats they had. fwiw, the gfs fi forecasts of what happens to that warming over siberia are hardly consistent and therefore to assume we are going to see a strong warming breaking up the vortex maybe a tad premature. however, displaced over siberia with no canadian daughter can still be very good for nw europe.

[Don]

Meanwhile, the canadian warming mainly evident at 50-100hPa intensifies in this period, with marked height rises becoming focussed on northern Canada.

Would this be signalling a west based NAO?

[UV-RAY]

I'm far from convinced that any warming that does occur will be beneficial to this tiny island, we've been discussing tropical waves and warming for what seems like months now and still no sign of any deep cold coming our way anytime soon.

[Cheshire Freeze]

I'm far from convinced that any warming that does occur will be beneficial to this tiny island, we've been discussing tropical waves and warming for what seems like months now and still no sign of any deep cold coming our way anytime soon.

I know, I'm starting to get fidgety now.

[bluearmy]

I'm far from convinced that any warming that does occur will be beneficial to this tiny island, we've been discussing tropical waves and warming for what seems like months now and still no sign of any deep cold coming our way anytime soon.

luck and timing SoN. never been any different for the uk !

keep the vortex displaced over siberia and hope that an atlantic ridge comes along at a time when there isnt any energy headed sw from it near greenland. then you get your greeny ridge and the rest follows .................

only one scenario that could deliver cold, there are others feasible with a displaced siberian vortex

[Glacier Point]

The ECM Ens mean for 240-360h has a very stretched PV (at 10hPa) from northern Scandi to northern Siberia, before re-intensifying into a more focussed vortex over central Siberia. In this period the upper strat warming (evident at 10-30hPa) over Siberia remains there, rather than propogating to the pole as per the Hi-Res GFS, and actually weakens slightly in situ in terms of anomalies. In fact over the Pole itself temperatures in the Upper Strat are stable or even cool slightly, with no major warming evident here.

Meanwhile, the canadian warming mainly evident at 50-100hPa intensifies in this period, with marked height rises becoming focussed on northern Canada.

..which is interesting because if the polar core temperatures are cold and relatively robust, the Canadian warmth rotates eastwards towards Greenland and supports heigh rises in time in this sector.

[lorenzo]

Stewart / Recretos - any idea which selection to use to create plots similar to this page from Cohen for December so far for this flux, would be interesting to compare in real time for December so far.

SLP one matches well with the paper for displacement warmings.

[feb1991blizzard]

Rip - snorter of a GFS 12z stratospheric run, not sure i believe that the cold air will be that close to us tropospherically speaking so not sure how valid the stratospheric forecast is but anyway, its the warmest at 30mb yet.

Further up, it looks like the warmer air starting to get wrapped into the core.

Edited December 18, 2012 by feb1991blizzard

[Glacier Point]

Indeed, violent movement in the pv starting around the 28th December, manifesting primarily at 30 hPa but shifting upwards a few days later on. We also continue to see warming of the very outer stratosphere.

At around day 8 we are seeing a moderate strength warming in the middle and upper stratsphere with the core warming over Canada which lasts until around day 12-13.

[chionomaniac]

The displacement of the vortex from the pole at 10 hpa is sill a little way away from a technical SSW but the angle of warming is good. So perhaps that would lead to a SSW by the 10th - which is perhaps why the latest GFS run is more in keeping with climatology.

[Recretos]

@Lorenzo: Well, by looking at it and the units (m2s-2), I don't think there is a pre-defined option for this in the reanalysis tools. To do an exact same plot, you would have to download datasets and basically manually "write" the algorithm for this parameter and plot it. I am not really sure how to get close to this. Maybe with some combination of vertical pressure gradients, Omega and/or 100mb eddy heights. But I think that is not really close to it. I understand it as a vertical wave propagation, but given the derived unit m2/s-2 this also has to do something with kinetic energy. Or maybe my physics are a bit rusty. I only had physics for 2 years in elementary school, so... yea... I am lacking basic theory in the area most important (or connected to) in my main interest, which is meteorology.

Perhaps 250mb streamfunction can be helpful.

Maybe GP as a pro, can shed some light on this.

Edited December 18, 2012 by Recretos

[lorenzo]

Thanks Recretos, I got lost within the datasets on the reanalysis pages, some further reading has explained a little more, looks like it was a bespoke model for that particular paper, maybe something within the datasets can provide a useful mirror to this.

For the wave activity flux (WAF) we used the three-dimensional expansion of the two-dimensional Eliassen Palm flux derived by Plumb (1985).

Back to EP Flux again, so are the Cohen charts a predictor pattern for EP vectors? Sorry lots of questions from me today and less answers, kind of thinking out loud, if so then perhaps we can look out for the patterns displayed on the tropospheric EP Flux charts.

[Recretos]

For the wave activity flux (WAF) we used the three-dimensional expansion of the two-dimensional Eliassen Palm flux derived by Plumb (1985).

The way I understand this, is that they took this(example) --> , and put it in a 3D mode, basically giving it spatial presentation, to see not just how strong the EP Flux is, but where exactly is it occurring, prior to the respected SSW mode (split / displacement).

How couldn't I see that before? I guess actually reading the paper might help me.

So I guess that the pattern chats and the WAF charts from Cohen, are basically in the same "family" so to speak. His EP flux charts should indeed correspond with the pattern constructs prior to SSW modes. Imho of course.

Edited December 18, 2012 by Recretos

[Cloud 10]

Cohen needs to get on this thread and explain himself!

[lorenzo]

Not going to duplicate this post into other threads but given the spillover of Judah Cohen work into the Winter model thread these abstracts are of interest, if anyone has any doubts of how on topic or relevant this is then suffice to say these conferences have not happened yet and are scheduled for 8th January 2013..

AO lead time for a Winter forecast

https://ams.confex.com/ams/93Annual/webprogram/Paper219135.html

AO events on subseasonal timescale.

https://ams.confex.com/ams/93Annual/webprogram/Paper219017.html

In terms of why give credence to Cohen and those asking about is it peer reviewed, yes Cohen is another Weather capitalist working for AER but this graphic for me gives at least one good reason for paying attention to work in this area.

[chionomaniac]

Another very disrupted forecast with great warming at 10 hpa. Again it is better at the end of the run, but there is still enough warming in a more reliable time frame.

And again, a standing wave type warming that doesn't seem to want to penetrate the vortex in the run, though at the end the vortex is severely distorted.

[Glacier Point]

1962 warming event at 10 hPa and 30 hPa at ten day intervals, heights and temperature anomalies....starting to show a similar type evolution.

01/12/62 - 10/12/62

10/12/62 - 20/12/62

20/12/62 - 30/12/62

... note the elongated vortex in the final frame at 30 hPa, stretched across the Pole.

Edited December 18, 2012 by Glacier Point

[Buriedundersnow]

Simply not true.

Look at +72.

http://www.wetterzen...cs/Rtavn721.png

If you went back 5 days and looked at what the models were predicting for the 21st Dec the HP was much further E.

Oh dear ECM you were way off!!

Edited by THE EYE IN THE SKY, 26 minutes

this was posted by THE EYE IN THE SKY in the mod thread and i think it shows quite well from the cohen paper just how far a shift west there has been compared to what was predicted

[Sean19]

Is this good or bad for us? I am not sure how to interpret it.

Simply not true.

Look at +72.

http://www.wetterzen...cs/Rtavn721.png

If you went back 5 days and looked at what the models were predicting for the 21st Dec the HP was much further E.

Oh dear ECM you were way off!!

Edited by THE EYE IN THE SKY, 26 minutes

this was posted by THE EYE IN THE SKY in the mod thread and i think it shows quite well from the cohen paper just how far a shift west there has been compared to what was predicted

[SMU]

Perhaps in the closed season we should reanalise every warming event to see where the subsequent H5 anomalies ended up-

Ive not spent long enough looking but im sure there will be strong correlations.-

S

[Buriedundersnow]

Is this good or bad for us? I am not sure how to interpret it.

i posted it more for chio to see the shift westward of the siberian high for a thing he is keeping an eye on.

with the high being more west than forecast we have a better chance of cold weather just keep an eye on the models.

[lorenzo]

Let's hope the one above wants to be repeating itself.. !

Spotted this image on the US Site. another version of the current warming wave no idea of the source looks like a higher res of GFS model, must be some code within it as it won't attach here.

Edited December 19, 2012 by lorenzo

[Robbie Garrett]

I am wondering if the warming phase will be sped up, Earth is currently inside a stream of solar wind flowing from the coronal hole, bottom right.... I am personally wondering if these events, generally associated with a Solar Minimum with increased geomagnetic activity are likely to increase this process...

Interesting read here.. Click

[lorenzo]

The EP vectors from ECM are looking a touch insane this morning at 10 hpa - not seen that before.

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

240 warming chart http://wekuw.met.fu-berlin.de/~Aktuell/strat-www/wdiag/figs/ecmwf1/ecmwfzm_ta1_f240.gif

2 pulses of warming now at the end of the GFS run and a decent sprinkling of Canadian / Greenland height rises throughout.