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Stratosphere Temperature Watch 2012/2013


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Thanks BF to the link to that paper - it is very much in line with previous thoughts reagarding the type of splits and displacements. Will read it later.

Edited by Paul
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"Most have been discussing some sort of warming since the start of Dec-"

With regards to the minor warming at the start of December, we were very close to that big easterly remember and the MET blogged on the potential link and said how this "may" have an effect our weather.

Warming at the start of Decemeber;

http://wekuw.met.fu-...cmwf1/temps.gif

Met office blog

http://metofficenews...pheric-warming/

Since then the strat has cooled again but this new forecast is much more significant so if that minor warming was influencing the blocking over Scandi/Russia that was close to bringing in an easterly, and bought parts of Norway some extremely cold and snowy weather, then the possibilities of the new much more significant warming (and an official SSW) influencing things can't be ignored.

Edited by chris55
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I seem to recall GP posting a 30 HPA temp of dec 1962-

Because we have data back this far in the NON winter season ( or indeed now) if someone had the time seeing as brickfielder has neatly grouped them into 3 types it would be good for support to go back & reanalise the last 40 years worth of significant warmings- The propergation time & subsequent H5 anomalies-

Im sure there will be some sort of order- whether it be 2 wave/3 wave etc & where the most likely H5 anomalys land-

if someone has the link to the table that showed the Nov dec jan & feb strat temps + QBO type & warming events I will do it if I have time

S

Edited by Steve Murr
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Thats a lot of Warmings-

It will take time-

The way I will do is take the month the warming took place find the peak temp of warming ( & date ) then reanalise the H5 anomalies in the subsequent 10-30 day time frame.

Canadian warmings will be seperated - hopefully with the other warmings we can differentiate different locations where the warmings have set up.

S

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my thanks for that Steve-I am well known for suggesting we need hard evidence for using analogues or any other type of linking. Too many folk with not a great deal of knowledge are quick to either knock something or jump on a band waggon rather than settling down reading all the available information, and trying to find just what is linked and what is not, or nothing if the research finds that.

I am sure chio and GP will appreciate your results whatever they are. Maybe a private discussion between the 3 of you to suggest the best things to look for?

good luck

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Wrong, your comments in here have for the most part not contributed constructivly what so ever. At every opportunity you've posted in here basically saying that SSW is a bust, GP's forcaste is a bust etc etc. At least steve backs his post with some kind of evidence an reasoning. YOU on the other hand post one liners and not a shred of evidence to back it up. So maybe if you go and research and spend some time on your posts they wont dissapear. The Likes of Rec, GP, Chino etc etc clearly spend an enormous amount of time to give us laymen like me some kind of insite into whats happened. And i have learnt so much more in this thread than all the other threads on this forum combined

The proof is in the pudding, the winter forecast is wrong simply because December didn't pan out like GP stated. Also I've never said that the SSW is bust, I simply implied that we may still end up on the wrong side of any displaced vortex, so presuming a SSW means cold for the UK is way off base. As for researching the subject, well I know enough to realise that there are still far too many variables which we yet don't fully understand and that is why all LRF struggle.
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Anyway, just wanted to post that Cohen will be releasing a paper in January about tropospheric precursors to large AO events, sounds like it could be a very helpful read and it hopefully builds on the knowledge of existing known precursors.

https://ams.confex.c...aper219017.html

Edited by Paul
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But if we had no SSW showing at the moment, the chance of cold would be in my opinion very low for the next 2 months. The SSW which is shown again on ECM this morning does not guarantee cold but it makes it so much more likely than if we didn't. So im excited and optimistic but also cautious for positioning of any remaining residual energy. We can only hope but surely in with a good chance is better than no chance at all because this SSW will change the horrible hemispheric pattern were in at the moment, then we pray and hope everything falls in the right place Posted Image

Edited by Paul
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The EP Flux is continuing to trend poleward which, with my limited knowledge, would be a positive addition in the long run;

post-12721-0-79412100-1356701116_thumb.j

With a strong possibility of a SSW soon, here is a good read up of the relationship between SSW's & the MJO;

http://www.meteo.psu.edu/~sbf1/papers/mjosswv6.pdf

Edited by AWD
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The EP Flux is continuing to trend poleward which, with my limited knowledge, would be a positive addition in the long run;

post-12721-0-79412100-1356701116_thumb.j

With a strong possibility of a SSW soon, here is a good read up of the relationship between SSW's & the MJO;

http://www.meteo.psu.edu/~sbf1/papers/mjosswv6.pdf

Thanks for that paper link AWD. That very much confirms my thoughts as discussed with Nick S the other day, so good to see that linkage studied.
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Just a quick question. During Nov/Dec we saw a very cold strat which, did not at the time, influence the tropospheric synoptics. Is the rather depressing output we now see in the models due in any way to a lag time effect of these earlier very cold temps?

I'm guessing it's rather more complicated than that, but given that strat warmings often take time to affect the trop is it the same for coolings?

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Thanks for that steve. It seems, as we are all aware, that propogation is the key. If this does downwell, we will be hugely unlucky to miss out on a cold spell. The well split gfs runs in the upper strat have all developed a strong greeny block from the other side of the pole. to see those patterns make their way down to the lower strat would indeed be reward for all the effort on here. Just watching and waiting unless ecm is sniffing a decent transitionary period. I would love someone to comment on the momentum flux charts from the berlin site and tell me that the apparent buffers to the energy below 10hpa are nothing to worry about re propogation.

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Thanks for that steve. It seems, as we are all aware, that propogation is the key. If this does downwell, we will be hugely unlucky to miss out on a cold spell. The well split gfs runs in the upper strat have all developed a strong greeny block from the other side of the pole. to see those patterns make their way down to the lower strat would indeed be reward for all the effort on here. Just watching and waiting unless ecm is sniffing a decent transitionary period. I would love someone to comment on the momentum flux charts from the berlin site and tell me that the apparent buffers to the energy below 10hpa are nothing to worry about re propogation.

BA couldn't this be a reaction to the EP flux, so until that moves poleward then the momentum is buffered.

I could be totally wrong! hopefully Chiono et al may have a better idea.

http://www-eaps.mit....1_notes/4_1.pdf

I'm not sure if this makes any sense!

I've deleted that as I think it's not the answer, but that link if you like equations is very enjoyable!

Edited by nick sussex
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All very well but there remains a strong possibility that we could see the vortex in unfavourable position for cold, as you are aware there are no guarantees when it comes to weather.

Of course there does, 7. Indeed, one SSW does not a winter make. Having said that, it's hard to where any Arctic/continental Blasts might come from, had there been no stratospheric warming at all?

And, am I mad, or does NW's seasonal forecast not speak in terms of probability - and not certainty?

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Afternoon All-

then the date give or take a day or 3 is the 14th of Jan 2013 for our biggest shot of COLD so far this winter.

( Obviously this is for our little neck of the wods at 50N)- move closer to 90N & the propergation will be quicker-

So look for a reversal of zonal winds at 70/80n for day 10, & that to extend south further in time.....

Anything that appears before then is a bonus.

S

thanks for all that effort Steve

Funnily enough the 30mb temperature hike on 23 December would suggest +/- a day or two that around 17 January would be the period to expect some kind of blocking to be affecting the Atlantic nw Europe area. That is using my much over simplified system of trying to connect the 30mb temperature spikes with blocking. Note I point out that the first spike led to nothing for the UK if we ignore the northern half of Scotland and its occasional dips into a northerly over the period straddling Christmas Day?

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post-12276-0-30342500-1356712802_thumb.p

Ey up!

Polar high decimates the vortex on the 12z and the stratospheric high ridges well south through the arctic... by D13, a nifty Greenland warming comes into play. Lots of solutions to come but the 12z is a beaut!

edit: difference between the two suites is that the 12z has strong warmth moving in from Siberia at 10hpa, fuelling the polar high and meridional flow to split the polar vortex- it's a superb run for polar vortex 'destruction' in the upper atmosphere, though not quite yet

Edited by Isolated Frost
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Thanks for that steve. It seems, as we are all aware, that propogation is the key. If this does downwell, we will be hugely unlucky to miss out on a cold spell. The well split gfs runs in the upper strat have all developed a strong greeny block from the other side of the pole. to see those patterns make their way down to the lower strat would indeed be reward for all the effort on here. Just watching and waiting unless ecm is sniffing a decent transitionary period. I would love someone to comment on the momentum flux charts from the berlin site and tell me that the apparent buffers to the energy below 10hpa are nothing to worry about re propogation.

I think you mentioned this a couple of days ago BA,i assume this is the type of chart you are

referring to with the "brick wall"around the 20 hpa mark.

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I think you mentioned this a couple of days ago BA,i assume this is the type of chart you are

referring to with the "brick wall"around the 20 hpa mark.

I think this is something to do with eddies in the flow, this might explain it better:

As mentioned above, the stratospheric and the tropospheric circulation are connected with each other through wave mean-flow interactions. The Eliassen-Palm (E-P) flux (Eliassen and Palm, 1961) is widely used to characterize the wave activity. The direction of the E-P flux is proportional to the group velocity and indicates the direction of the propagation of the waves. Approximately, the vertical and horizontal components of the E-P flux are proportional to the eddy heat and momentum flux, respectively. The divergence of E-P flux is proportional to the northward flux of quasi-geostrophic potential vorticity, so that it is a direct measure of the total forcing of the zonal-mean flow by eddies. Therefore, the E-P flux and its divergence are important and useful to diagnose planetary waves propagation as well as the effective mean zonal force induced by the waves. Some figures on this web page display E-P fluxes under different forms, such as meridional cross-sections and time series, for monitoring the stratospheric circulation.

Thats from the JMA notes on SSW's:

http://ds.data.jma.go.jp/tcc/tcc/products/clisys/STRAT/html_e/readme.html

I think there has to be a correlation between EP flux direction and the momentum flux, so they work together, if the EP goes poleward that might exhibit greater forcing on momentum to drive the propogation.

Perhaps I've got the wrong end of the stick but it would seem a logical conclusion to make,hopefully Chiono and some of the others more versed in the strat might shed some light on this.

Edited by nick sussex
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thanks for all that effort Steve

Funnily enough the 30mb temperature hike on 23 December would suggest +/- a day or two that around 17 January would be the period to expect some kind of blocking to be affecting the Atlantic nw Europe area. That is using my much over simplified system of trying to connect the 30mb temperature spikes with blocking. Note I point out that the first spike led to nothing for the UK if we ignore the northern half of Scotland and its occasional dips into a northerly over the period straddling Christmas Day?

The warming seen in early December which almost produced a blocked and very cold spell was a

bottom up warming which had an impact almost straight away. That has now long gone. The warming

we are seeing in the strat charts is a top down warming.

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The warming seen in early December which almost produced a blocked and very cold spell was a

bottom up warming which had an impact almost straight away. That has now long gone. The warming

we are seeing in the strat charts is a top down warming.

I assume that top down is not as good/immediately effective as bottom up(so to speak) warming?

I'm very intrigued by stratospheric modelling, I'm not good at all this stuff but I would like to learn, is there a website that could help me?

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The EP Flux is continuing to trend poleward which, with my limited knowledge, would be a positive addition in the long run;

post-12721-0-79412100-1356701116_thumb.j

With a strong possibility of a SSW soon, here is a good read up of the relationship between SSW's & the MJO;

http://www.meteo.psu...rs/mjosswv6.pdf

Probably completely wrong but I get the impression that this strat warming is leading the

MJO rather than the other way around.

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||

It was the original comment that didnt belong- You should have removed that- all my original posts were related to the thread topic. IE the strat.

The comparison was rather odd- a specific synoptic set up that brings snow to the UK or an event in the stratosphere-?

All I am doing is putting a realistic slant on it- Most have been discussing some sort of warming since the start of Dec-

On Average the propergation time is circa 21 days from top to bottom-

With that in mind the discussion of this event will span from ~ 5th of december- to the event ~ 5th of Jan- through the propgation wave ~ 15th- 25th jan--

That spans ~40-50 days building an expectation from something that is only just greater than say 50% of delivering something for us.

Something MAY happen sooner for the UK- then that begs the question was it related to the strat or not..

Possibly but because of the rest of the lower trop influences we cannot be sure.

I think you need to be consistent in the moderation & comments-

S

I am glad you responded to this Steve as I was about to post something on your behalf! I really appreciated your original post - it's good to get a reality check into this thread. Whist I do appreciate this is a stratosphere temperature watch thread, I think it's most useful when this is discussed within the context of the many other variables which can affect our weather and all the associated complexities and uncertainties surrounding how these all interact. You also explain things in a way which is understanable to those of us with less technical knowledge so please keep posting!!
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