Stratosphere Temperature Watch 2012/2013

[Southern Storm]

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?

great post as always, just a quick question from me, how does this year compare with the mighty year of 1962? Or do we not have enough data from back then?

I recalled someone mentioning that there was a Canadian warming that year similar to the one that's happening now if Im not mistaken.

I know a few people have been burned this last week with the failed eastery, but some of the best winters never got going until late December early January time, and even though I'm only just starting to get to grips interpreting the models I really feel something special is just around the corner!

[mcweather]

Hi Chiono, a very interesting post indeed and certainly something to keep an eye on in the medium to longer term. As you say the models seem to be picking up on the initial nudgings west of the Siberian high in their longer range at the moment. This also ties in quite well with GP'S winter forecast.

One question, in this respect would you expect the models by the middle of next week to be showing a lot more blocking scenarios in their medium range operational and ensemble output?

[chionomaniac]

Hi Chiono, a very interesting post indeed and certainly something to keep an eye on in the medium to longer term. As you say the models seem to be picking up on the initial nudgings west of the Siberian high in their longer range at the moment. This also ties in quite well with GP'S winter forecast.

One question, in this respect would you expect the models by the middle of next week to be showing a lot more blocking scenarios in their medium range operational and ensemble output?

I don't think that we will see a lot more blocking scenarios next week. We will probably see more variations of the one blocking scenario if my premise is correct. That is the Siberian high nudging west. We may eventually see a transient ridge from the Atlantic combine with the siberian high as it crosses the UK. In all, it is a good test of what we would expect climatology to produce and what does actually occur.

Edited December 14, 2012 by chionomaniac

[chionomaniac]

great post as always, just a quick question from me, how does this year compare with the mighty year of 1962? Or do we not have enough data from back then?

I recalled someone mentioning that there was a Canadian warming that year similar to the one that's happening now if Im not mistaken.

I would say that we have not seen a warming large enough to be classified as a Canadian warming, now. There is not enough data on the 1963 event to reliably examine and compare.

[Southern Storm]

I would say that we have not seen a warming large enough to be classified as a Canadian warming, now. There is not enough data on the 1963 event to reliably examine and compare.

OK thanks for that, fingers crossed that we do get a SSW as i believe there will be a lot

More focus on the next one and all the new data it will bring.

Edited December 14, 2012 by thunderman24

[Gael_Force]

A good write-up of the stratospheric events of January 1963.

http://journals.ametsoc.org/doi/pdf/10.1175/1520-0450%281964%29003%3C0001%3ATMWSWA%3E2.0.CO%3B2

[mcweather]

I don't think that we will see a lot more blocking scenarios next week. We will probably see more variations of the one blocking scenario if my premise is correct. That is the Siberian high nudging west. We may eventually see a transient ridge from the Atlantic combine with the siberian high as it crosses the UK. In all, it is a good test of what we would expect climatology to produce and what does actually occur.

Thanks Chiono this strat stuff is really interesting.Your informative posts have hugely increased my understanding of the possible effects.

[Isolated Frost]

Unfortunately the 10hpa temp at 360 is max -2c, yesterdays 12z had it at about 9c at 384- so perhaps the warming is now seeing it's dilution begin ?

However, the latest run shows the vortex energy in Novaya Zemlya at 384- and it's notably warmer across NE Canada/Greenland- that would be more conductive to something at home

Edited December 14, 2012 by Isolated Frost

[kold weather]

Whilst no where near warm as the 06z, the key thing to note from the 12z GFS this run is how well embedded the warming air is in the arctic circle by 384hrs. We almost cut off the cold air into a bubble.

IF, I'm fairly sure -4C or so would still probably do the job, especially as its clearly getting rotated into the whole PV structure by the end.

Edited December 14, 2012 by kold weather

[lorenzo]

Just catching up to some fantastic posts and bewildering temperature figures. Stunning.

Once that warming wave gets wrapped into the core of the Vortex it will collapse, spilling out lots of cold goodness, will be fascinating to see what trop. picture develops - surely some form of instantaneous response. Good also that into the realms of 240 charts now, adds extra confidence, Let the games begin !

[phil nw.]

Just catching up to some fantastic posts and bewildering temperature figures. Stunning.

Once that warming wave gets wrapped into the core of the Vortex it will collapse, spilling out lots of cold goodness, will be fascinating to see what trop. picture develops - surely some form of instantaneous response. Good also that into the realms of 240 charts now, adds extra confidence, Let the games begin !

I have just said something similar in the model thread L.

Although the temperature of the warming is a little lower on this run i think we have some leeway havent we?

I am sure i read somewhere that we need a rise of at least 40C above the norm.to be an effective SSW or is my old memory playing tricks?

[chionomaniac]

Unfortunately the 10hpa temp at 360 is max -2c, yesterdays 12z had it at about 9c at 384- so perhaps the warming is now seeing it's dilution begin ?

However, the latest run shows the vortex energy in Novaya Zemlya at 384- and it's notably warmer across NE Canada/Greenland- that would be more conductive to something at home

That's nothing to worry about, IF. At that range there is bound to be interrun changes - and over 0ºC was incredible any way.

Here is the traditional CPC T+0 and T+240 images to compare - and remember at T+240 the warming has hardly begun (the cpc 10 hPa scale's max is -15ºC!!!)

[lorenzo]

Might have been this Phil? Looks like it is a million dollar question, or atleast one that a few have asked.

Cannot locate the paper cited in pdf form, it looks like it is online somewhere but no abstract listed and only links I can find come with a fee. I think that with temp rises at 80-100 degrees then we are safely into Major Warming if not unchartered territory!

Great breakdown of Cohen C, looking forward to watching that pan out, especially this prediction..

Looking at the Cohen bibliography, this author has been on the case with Siberian Highs since 2001 - obsession or what !!

@Recretos, some fine analog work there, no idea how you went about creating those charts on the map room. Superb stuff.

[phil nw.]

Cheers Lorenzo.Yes that paper re.the 40C rise looks familiar-that at 50hPa though.

Still as you suggest what we have forecasted is something pretty impressive.

[cooling climate]

I made several posts in the model thread in the last two weeks or so

mentioning the size of the Siberian high and then we came so close to

tasting it.

Surely this will be a big player this winter. Certainly more very

encouraging signs strat wise but then having read the various Cohen

papers given the size of the high it should come as no surprise really.

Fun times ahead hopefully.

[kold weather]

That's nothing to worry about, IF. At that range there is bound to be interrun changes - and over 0ºC was incredible any way.

Here is the traditional CPC T+0 and T+240 images to compare - and remember at T+240 the warming has hardly begun (the cpc 10 hPa scale's max is -15ºC!!!)

I've got a question, could the start of a warming event briefly strengthen the PV, IE the temp gradient increases and this briefly tightens the PV up as the cold air gets forced into a tighter and tighter ball. Eventually the thing has to 'pop' so to speak and disintergrate as the warm air is shoved into the core.

[chionomaniac]

I've got a question, could the start of a warming event briefly strengthen the PV, IE the temp gradient increases and this briefly tightens the PV up as the cold air gets forced into a tighter and tighter ball. Eventually the thing has to 'pop' so to speak and disintergrate as the warm air is shoved into the core.

I am sure that that does occur in the stratosphere - how that it may translate to the troposphere I am not too sure, looking at Cohens' works.

[Recretos]

@Recretos, some fine analog work there, no idea how you went about creating those charts on the map room. Superb stuff.

The power of NCEP/NCAR reanalysis tool is really awesome. I got the idea to make some correlations when there was talk about snow, not really knowing how much of a common understanding it is in here.

@Chionomaniac: Thanks for the link. I will have some time to spare this weekend, so I hope I will be able to go through some papers.

I cant help myself, not to wonder, if there is such a difference in the 8-10 day period, how much of a difference can there be on the 384h up in the strat. Of course because of the different idea of the action below, there could easily be some differences in the action "above".

Edited December 14, 2012 by Recretos

[Snowy Easterlies]

forgive me for my ignorance but dosen't this warming look to far away to effect us

[Recretos]

forgive me for my ignorance but dosen't this warming look to far away to effect us

http://modeles.meteo...h-10-336.png?18

To put it simple, you shouldn't look at this forecasted warming as something that would have like a direct local effect. Look at it as a feature that affects the general overall dynamics in the stratosphere. So basically it affects you locally down the road, but through succession and not directly.

IMHO of course.

Edit: I add "imho" to my posts a bit often. The reason for it is, that around this time last year I had no idea what SSW stands for, and I had no idea what an SSW is. All I knew about stratosphere a year ago, was that there is a cyclonic feature a.k.a. polar vortex present up there, and it somehow affects us down here. So I am less than a year in this whole "strat business", with lots of stuff to learn, but trying to keep a high pace.

Edited December 14, 2012 by Recretos

[bluearmy]

forgive me for my ignorance but dosen't this warming look to far away to effect us

http://modeles.meteo...h-10-336.png?18

a bit like saying that el nino or la nina is in the south pacfic so whats it got to do with us. its a global word now dont ya know !

[LomondSnowstorm]

a bit like saying that el nino or la nina is in the south pacfic so whats it got to do with us. its a global word now dont ya know !

I so despise that phrase 'a global world', but anyway yes, it has a major impact on the polar vortex which has a major impact on us. I understand why you'd think that though, because tropospheric changes in pressure patterns 'upstream' don't necessarily have a major impact on our weather patterns.

[feb1991blizzard]

forgive me for my ignorance but dosen't this warming look to far away to effect us

http://modeles.meteo...h-10-336.png?18

Without this happening you would not have got the massive dumping you recieved on 1st feb - 2nd feb 09.

It all started over the other side of the hemisphere though, as long as the PV gets blasted then it affects us all, and as long as we dont end up on the wrong side of any troughing then usually positively.

http-~~-//www.youtube.com/watch?v=mIXfYTSmBg0

Not wishing to be a party pooper but any realistic chance of a decent snowfall before xmas is receeding fast and even from a novices point of view, i suggest this is the most important thread for anyone interested in snow, i am far more interested in whats going on way above planet earth NWP wise than the surface now.

Edited December 14, 2012 by feb1991blizzard

[bluearmy]

the 18z gfs splits the vortex up to 30hpa around T300. not a great position for us with our side of the nh around ne greenland area, though it doesnt look particularly stable. (with the east siberian mother vortex stronger.)

good job the warming is coming round to interfere with it. will be interesting to see how it mixes into the p/v as mid/upper strat temps near the pole are still average out to the end of the run.

[feb1991blizzard]

the 18z gfs splits the vortex up to 30hpa around T300. not a great position for us with our side of the nh around ne greenland area, though it doesnt look particularly stable. (with the east siberian mother vortex stronger.)

good job the warming is coming round to interfere with it. will be interesting to see how it mixes into the p/v as mid/upper strat temps near the pole are still average out to the end of the run.

That split has gone on the 0z. more warmth starting to get into the core at both 10mb and 30mb.

especially at 10hpa, that massive slither of red is back as well indicating + temps.

That will do me fine, only thing worth bothering about in NWP output at the moment, lets hope it is reflected soon in the ECMWF.