Stratosphere Temperature Watch 2012/2013

[chionomaniac]

This is a new thread for me and one which I am slowly starting to understand. Just a quick question form me. Will the metoffice be aware of this forecasted warming of the stratosphere? If so will their 6-30 forecast change to show a more colder outlook? Many thanks GSL

I am sure that the UKMO will be aware of the strat warming forecasts. I don't know when this will come through in the updated GloSea4 model - but I would expect to see a more variable forecast within a week for the end of the period.

[feb1991blizzard]

I am sure that the UKMO will be aware of the strat warming forecasts. I don't know when this will come through in the updated GloSea4 model - but I would expect to see a more variable forecast within a week for the end of the period.

To a certain extent chiono, they already are, they mention a great deal of uncertainty as one might expect but then also mention the possibility of more settled conditions, obviously that is very open and suggests high pressure more influential, whether they think that be to the North, North East or North West or anywhere less favourable is anybodys guess.

Edited December 13, 2012 by feb1991blizzard

[Recretos]

thanks for that GF - its just meteociels representation of temps only that is misleading

Yep. Its misleading because it only shows temperature. The center is still fairly good visible from the gradients and the general shape, but as others have already pointed out, the geopotential height maps are the ones you need to look at, if you want to know where exactly is the forecasted center.

[chionomaniac]

Latest GFS 18Z predicted warming at 10 hPa. The warming is so great that Paul has had to regrade the temperature scale!!!! (Thanks!)

Max temp 14.3ºC!!!!

(PS Paul - looks like another addition may be necessary!)

Edited December 13, 2012 by chionomaniac

[Glacier Point]

18z GFS gives us a projected 85C rise in 10hPa temperatures over central Siberia from start to finish. Final frame looks to me to be point where the polar night jet is undergoing wavebreaking, meaning a rapid intrusion of the warm air anomalies as the jet suddenly deccelerates.

Might just be worth keeping tabs on extended GFS ops as there may be a fast response wave induced down through the troposphere as well as the more traditional day +20 downwell.

PS. 5hPa temps off the scale and a more impressive (if that's possible) near 100C rise in temps in this area from start to finish.

Edited December 13, 2012 by Glacier Point

[Recretos]

Wow. http://forum.nwstatic.co.uk//public/style_emoticons/<#EMO_DIR#>/ohmy.png This could be a major if it comes to fruition. If nothing else, at least the trend is good for now.

[Duane S.]

Having all been recently burnt by the Easterly that never was it's nice to see the more stable stratospheric forecasts of late. Could anything now scupper this warming event Chiono? Obviously the intensisty could and probably will reduce but how set in stone is a strong warming at this stage?

Oh and GP's comment ref the forecast 100 deg increase at 5hpa, in that timescale, is still (but not yet) sinking in. Outrageous.

[Buriedundersnow]

Just been reading back through the Cohen et al. Paper on SAI and corresponding stratospheric feedback, and I think this paragraph stood out for me:

I think you can see where I am placing the emphasis there, and this was certainly the case in 2009/10, though of course we did also end up with a cold spell in mid-late December that year. Would anyone happen to have a link to the eurasian snowfall advance in 2009 to see if it happened any quicker than this year?

SK

http://www.natice.noaa.gov/ims/gif_archive.html

[Recretos]

Since NH snow cover is being mentioned, I was playing around with the correlations tool, and I think you will find the results quite interesting, especially when compared to the latest GFS forecasts.

Keep in mind that I have put a 2 month lag between the two values, giving the NH Snow cover a 2 month lead. Correlations above 0.7 or below -0.7 are very good, I would say. And of course we all know there is more than just the snow cover in the picture, when it comes to MMW's. But the correlations speaks for themselves, keeping the snow cover as an important factor, not really directly, but more in a general way like @snowking was quoting from a paper from Cohen et. al.: "

We suggest that the intensification of the Siberian high, along with the thermal impacts of enhanced snow cover and topographic forcing, corresponds to a positive wave activity flux anomaly in the late fall and early winter, leading to stratospheric warming and to the January tropospheric negative winter AO response we have mentioned above."

That is probably why the best correlation appeared when I applied a 2 month lag (Snow cover leading). Which means that the parameter period (Dec-Jan) is being correlated with the snow cover from Oct-Nov. Below on the graph, the 2012 snow cover anomaly is presented for that same period.

And latest in the "pattern" area.

Correlations.

Based on these correlations, I would say that the latest GFS forecasts are very likely to come into fruition, probably not as hardcore as they are now, but in the same "spirit".

In my humble opinion anyways.

p.s.: I used the 1980-latest(I think NCEP needs to update their correlation datasets, because the latest parameter values are for 2007) correlation period, basically because of the realistic data after 1980, when the satellite era began.

Best regards.

Edited December 14, 2012 by Recretos

[Isolated Frost]

Indeed the GFS 0z downgrades the 384 warming from 14c to 4c at 10hpa- hopefully the trend is just a freak for now, mind you, the 0z would eventually get very near, it seems under-progressive in comparison to previous runs.

[chionomaniac]

Recretos - have you seen J Cohen's work regarding stratospehric warming feedback from rate of gain of October Eurasian snowcover? This is well known and has been illustrated many times on here - it confirms what you are trying to show.

We are seeing the first signs of warming brought into the ECM at 10 Hpa today at T+240 - so we can start to watch this come into the reliable now.

The GFS still has a strong warming forecast - perhaps not quite as strong as last night - only up to 4.5C!

[kold weather]

The 00z is a little slower but 4C max and probably still warming at 384hrs from the looks of things would still more than likely do the job of finishing off what is already still a fairly unstable vortex. You aren't going to see a solid temp rise of 40-50C in 5 days or so not cause havoc on the PV.

[Recretos]

Recretos - have you seen J Cohen's work regarding stratospehric warming feedback from rate of gain of October Eurasian snowcover? This is well known and has been illustrated many times on here - it confirms what you are trying to show.

Actually I haven't read any of his papers yet. And neither have I read this whole thread. I was almost 100% that this is nothing new, but I still thought it might be interesting. Sorry about that. I will try to look around next time before I post.

[chionomaniac]

Actually I haven't read any of his papers yet. And neither have I read this whole thread. I was almost 100% that this is nothing new, but I still thought it might be interesting. Sorry about that. I will try to look around next time before I post.

Keep doing what you are doing, recretos. It was good to see that you have reached the same conclusion as Cohen in what was probably a fraction of the time!!

[Shuttler]

I'm relatively new to this Forum, some fantastic posts and a huge learning curve for me, and cutting edge. Thanks to all.

FWIW, the ECM Ensemble mean from T240 to T360 maintains the PV directly over Novaya Zemlya/Kara Sea, and intensifies and propogates the warming seen over Siberia at T240 driving it towards the pole. 10hPa temps climbing to between -20 to -24C over Siberia, that's an anomaly around +18 to +21C. Being an Ensemble mean it's not as extreme as the GFS/ECM ops. But the trend is definitely there.

[bluearmy]

I'm relatively new to this Forum, some fantastic posts and a huge learning curve for me, and cutting edge. Thanks to all.

FWIW, the ECM Ensemble mean from T240 to T360 maintains the PV directly over Novaya Zemlya/Kara Sea, and intensifies and propogates the warming seen over Siberia at T240 driving it towards the pole. 10hPa temps climbing to between -20 to -24C over Siberia, that's an anomaly around +18 to +21C. Being an Ensemble mean it's not as extreme as the GFS/ECM ops. But the trend is definitely there.

Well shuttler, if you have access to the ecm ens mean at day 15, you are a very welcome addition to the forum !

[Shuttler]

Yes I do, but with usual restrictions with paid for data...

[chionomaniac]

Welcome Shuttler, the more the merrier!

Recretos, this paper may be of interest to you and others. One of Cohens.

http://web.mit.edu/jlcohen/www/papers/CohenandJones_JC12.pdf

[chionomaniac]

Up to 9.2C this run at 10 hpa and starting to show at the more southern latitudes in the high res output.

[bluearmy]

Might just be worth keeping tabs on extended GFS ops as there may be a fast response wave induced down through the troposphere as well as the more traditional day +20 downwell.

noted on the 06GFS and also the naefs 00z spreads seemed to be showing some high heights headed towards to pole north of the aleutians

[southbank]

a very informative forum if slightly above my head , but if im "getting " this right , are we saying that warming of Pole are expected to be higher than usual which impacts the PV which in turn leads to a decrease of westerly winds leading to HLB ? Also in the next few days we may see tentaive signs of an AH in NWP ?

Edited December 14, 2012 by southbank

[chionomaniac]

Welcome Shuttler, the more the merrier!

Recretos, this paper may be of interest to you and others. One of Cohens.

http://web.mit.edu/j...dJones_JC12.pdf

I have just re read this paper and would like to point out some aspects.

Firstly, the large Siberian high is a classic precurser to a displacement type SSW. If one focuses solely on the displacement type SSW precursers then the article highlights some important pressure anomalies that we may witness both prior and following a displacement SSW.

Interestingly, climatology suggests certain pressure pattern precursors prior to the displacement SSW. If as I suspect that we will see a displacement SSW around the 10th January then we can work back from there using that date as being T+0.

So at T -28 to -21 days we are likely to see a large Siberian high in Situ. This fits in the current timeframe ie occurring now! And lo behold that is indeed what we see!

From -21 to -14 days this Siberian high will back west, (yes west!) so that by days -14 to -7 the centre of the large high is based towards the Northeast of the UK - slap bang on the west coast of Scandinavia. By my reckoning that period will be shortly before and after New Year.

We have already seen a trend picked up with the models hinting at the Siberian high backing west and with such a strong possible SSW forecast, this fits in well with climatology.

So what after a possible SSW I hear you ask?

Well, climatology suggest that we will see significant polar height rises from days T+0 to T+45 and these will be especially prevelent over the Greenland area.There is also a likelihood that we will see 3 bursts of raised heights, one between days 4 and 12, a smaller one between days 20 to 25, and the largest between days 30 and 45.

Now all we have to do is sit back and watch to see if this occurs, and if it does, will we be lucky enough to benefit?

[BLAST FROM THE PAST]

Nice read Ed.

Considering that, and the very near miss we just had it suggests IMO an enhanced chance the deeper into winter to what we've just had....and we were close this time. That is one serious Siberian HP

BFTP

[Winter Monsoon]

Up to 9.2C this run at 10 hpa and starting to show at the more southern latitudes in the high res output.

Would i be right in saying those are record temps??

[chionomaniac]

Would i be right in saying those are record temps??

They are only forecasts, but I think that they will be close to the highest recorded. Haven't located that info yet - just means.