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Stratosphere Temperature Watch 2012/2013


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Posted
  • Location: Skegness,lincolnshire
  • Weather Preferences: Snow Heat thundersnow heatwaves and freezing fog
  • Location: Skegness,lincolnshire

    Hello chio iv really found this thread very interesting i seem to be learning new stuff every day just a quick question is the deep lp thats in the atlantic is that part of the polar vortex thats split away after the ssw and could it open the door for a GH after its moved away or is it normal

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    Steve whilst I agree to a certain extent, more especially with regards to the difficulty in forecasting exact placement of tropospheric synoptics (particularly with regard to the UK in the overall sch

    Posted Images

    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    Hello chio iv really found this thread very interesting i seem to be learning new stuff every day just a quick question is the deep lp thats in the atlantic is that part of the polar vortex thats split away after the ssw and could it open the door for a GH after its moved away or is it normal

    The Atlantic low is influenced by the Canadian polar vortex segment breaking free from it's moorings as it where. Whether a GH can form or not depends on where the vortex tries to reform.
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    Posted
  • Location: Isle of Lewis
  • Weather Preferences: Sun in summer, snow in winter, wind in Autumn and rainbows in the spring!
  • Location: Isle of Lewis

    thanks for your reply,maybe between my hunch and your science we might just see another cold blast!

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    Posted
  • Location: E Lancs, 900ft asl
  • Weather Preferences: Snow, blizzards, cold, thunderstorms, frosts, fog, general extreme weather
  • Location: E Lancs, 900ft asl

    Ed (or anybody),

    Just a quick one but is there a proper listing something of archived SSW events online?

    Cheers, Matt.

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    Posted
  • Location: st albans
  • Location: st albans

    ed - any comment on the below taken from TWO ?

    I do think that the synoptics we have seen recently has been largely due to the SSW,trouble is,as I said on here, because the 10hPa zonal wind did not really reverse,wave energy was still able to propagate,and dissipate,up into the higher statosphere as we saw with the temperature profiles for 5hPa,1hPa.

    When you get a sudden warming in the 10hPa layer it has to be in a (closed) isotherm,and winds have to reverse.they stayed negative,so that wave energy was able to penetrate past this layer.

    When we have a situation like this the sudden warming at 10hPa should have (reversed) the zonal wind at that layer,meaning that wave energy could not penetrate a stong easterly wind,therefore it would break (below)heating the layer below,this in turn would reverse the zonal wind so that any energy reaching that level could also NOT penetrate,and so on until the enegy got to the bottom layers of the stratosphere,and finally the troposphere.

    f5

    were we living in a parallel universe where the flow didnt really reverse ?

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    Ed (or anybody),

    Just a quick one but is there a proper listing something of archived SSW events online?

    Cheers, Matt.

    Not sure there can be a definitive list because the author's can use differing selection criteria. Below are the dates I have been using -

    Cohen & Jones

    30/01/58

    30/11/58

    16/01/60

    23/03/65

    08/12/65

    24/02/66

    08/01/68

    27/11/68

    13/03/69

    02/01/70

    17/01/71

    20/03/71

    02/02/73

    22/02/79

    29/02/80

    04/12/81

    24/02/84

    02/01/85

    23/01/87

    08/12/87

    14/03/88

    22/02/89

    15/12/98

    25/02/99

    20/03/00

    16/12/00

    11/02/01

    02/01/02

    18/01/03

    07/01/04

    21/01/06

    24/02/07

    22/02/08

    24/01/09

    09/02/10

    Martineau

    27/02/52

    24/12/53

    20/03/54

    08/02/57

    31/01/58

    04/12/58

    19/03/59

    17/01/60

    17/03/61

    11/02/63

    20/03/64

    21/12/65

    27/02/66

    09/01/68

    30/11/68

    05/01/70

    20/01/71

    04/02/73

    17/03/74

    11/01/77

    27/02/79

    01/03/80

    06/02/81

    27/01/82

    04/03/84

    03/01/85

    27/03/86

    26/01/87

    12/12/87

    14/03/88

    23/02/89

    28/01/91

    19/01/92

    03/01/94

    06/02/95

    08/01/98

    18/12/98

    01/03/99

    18/02/01

    01/01/02

    18/01/03

    09/01/04

    16/03/05

    25/01/06

    24/02/08

    29/01/09

    31/01/10

    17/01/12

    Combined this gives 55 between 1952 and January last year, 10 of which are the second in the season. This list is not exhaustive - although they don't give their dates, by using an alternative selection process Nakagawa & Yamazaki isolated 51 SSW between Sept 1957 and August 2002 even after discarding some events. The joint Cohen & Jones / Martineau list only mustered 42 over the same period.

    Edited by Interitus
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    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    ed - any comment on the below taken from TWO ?

    I do think that the synoptics we have seen recently has been largely due to the SSW,trouble is,as I said on here, because the 10hPa zonal wind did not really reverse,wave energy was still able to propagate,and dissipate,up into the higher statosphere as we saw with the temperature profiles for 5hPa,1hPa.

    When you get a sudden warming in the 10hPa layer it has to be in a (closed) isotherm,and winds have to reverse.they stayed negative,so that wave energy was able to penetrate past this layer.

    When we have a situation like this the sudden warming at 10hPa should have (reversed) the zonal wind at that layer,meaning that wave energy could not penetrate a stong easterly wind,therefore it would break (below)heating the layer below,this in turn would reverse the zonal wind so that any energy reaching that level could also NOT penetrate,and so on until the enegy got to the bottom layers of the stratosphere,and finally the troposphere.

    f5

    were we living in a parallel universe where the flow didnt really reverse ?

    f5 normally quite accurate but I don't think that he is taking the direct vortex positioning into account following the SSW. As if the split vortex and subsequent tropospheric positioning and reduced vortex strength could have possibly been achieved without the SSW! This is where we see a lot of theoretical ideology about propagation of SSW's without actually just looking at how the split has directly affected the troposphere.

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    Posted
  • Location: st albans
  • Location: st albans

    f5 normally quite accurate but I don't think that he is taking the direct vortex positioning into account following the SSW. As if the split vortex and subsequent tropospheric positioning and reduced vortex strength could have possibly been achieved without the SSW! This is where we see a lot of theoretical ideology about propagation of SSW's without actually just looking at how the split has directly affected the troposphere.

    and the zonal wind reversal at 10hpa ? that didnt happen ?????? that was more my point

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    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    and the zonal wind reversal at 10hpa ? that didnt happen ?????? that was more my point

    Oh yes just reread.

    ???????

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    Posted
  • Location: Exile from Argyll
  • Location: Exile from Argyll

    Ed (or anybody),

    Just a quick one but is there a proper listing something of archived SSW events online?

    Cheers, Matt.

    I posted this in another thread - it's the tabulated form of the archive.

    Posted ImagePosted Image

    The table of events since records started being kept.

    You will get the key and comments from this article.

    http://www.geo.fu-be...pole/index.html

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    Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

    Now i know that you guys are all looking for cold however in recent springs (2009, 2011, 2012) we have seen at least one very warm spring month possibly as a result of a large stratospheric rebound. I guess my question is do you expect the stratosphere to rebound well below average as we head into spring.

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    Posted
  • Location: Netherlands
  • Weather Preferences: Hot summer, Cold winter
  • Location: Netherlands

    Stratospherically we are still seeing a NH pattern dominated by the recent SSW. Contrary to some opinions, this has downwelled from the mid stratosphere and affected the troposphere. It is always hit and miss how and where the SSW can have knock on effects in the troposphere and it appears that we have been lucky to see the split vortex favourably positioned to prevent the jet stream powering through during the two week mid January period.

    However, that is about to change as further warming of the stratospheric Canadian vortex which allows it's tropospheric counterpart to break free. West to east momentum initially is set to carry this across the Atlantic to its Siberian counterpart as can be seen in this 30 hPa chart.

    post-4523-0-08087600-1358854751_thumb.pn

    As this occurs there will be a corresponding increase in Atlantic mobility allowing the westerlies to reach the UK rather than be held at bay. The stratospheric vortex even though weak will be positioned on the Atlantic sector meaning a far less meridional jet stream whereas the Pacific sector will have a far more disturbed flow due to the upper ridge holding strong. This pattern will be as of a direct consequence to recent stratospheric events - but the wheel of fortune will be dropping off the meridional cold flow elsewhere in the NH.

    So the main question that everyone is asking is will we likely to see a pattern re- emerge that can bring back the cold and blocking to our shores. And the answer is not immediately but definitely not no!

    With the weakened vortex conditions likely to persist for a period of time then it is only a matter of time before realignment occurs in line with the MJO and GWO.

    The stratospheric forecasts during the next 10 days right up to 10 hPa are showing and will show signs of increased fluctuations in the exact position of the vortex.

    There are signs of another split occurring around day 10 and this will need to be watched carefully.

    post-4523-0-30403700-1358855796_thumb.pn

    post-4523-0-98373000-1358855810_thumb.gi

    If this does occur then we could quite easily see the door to returning cold opened back up again. I think we will need to keep an eye on the strat forecasts very closely in this period.

    Dear Chio, thanks for all your interesting and exciting posts. I think that you contributed a lot to the knowledge about stratosferical processes and the the prediction and effects of SSW's! My compliments for your work here.

    I am still struggling, though, with the developments of next week. You state that the stratosferical canadian vortex (30 hpa chart) is moving to the atlantic and is trying to move to/merge with the siberian vortex. Why is that movement so strong with a heavily weakened vortex?

    Troposferically (500 hpa) i see the same movement: a lot off LP-energie comes across the atlantic and is moving to Skandinavia, the Jet is moving further North.

    Posted Image

    It suggests that those stratosferical and troposferical movements are coupled. They coincide at least in time. You wrote in your post that due to continued warming of the stratosferical vortex above Canada, the troposferical one brakes free. Am I overseeing something or is this just coincidence.

    I am eager to learn so please forgive me my possible stupid question.

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    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    Not a stupid question, skatefan.

    The tropospheric vortex and residual stratospheric vortex is still strong enough to create this affect. The stratospheric Canadian vortex is being further warmed at 10 hpa which is higher up than 30 hpa. It is only when the vortex is weakened at this level that the tropospheric Canadian vortex begins to wander across the Atlantic.

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    Posted
  • Location: Netherlands
  • Weather Preferences: Hot summer, Cold winter
  • Location: Netherlands

    Not a stupid question, skatefan.

    The tropospheric vortex and residual stratospheric vortex is still strong enough to create this affect. The stratospheric Canadian vortex is being further warmed at 10 hpa which is higher up than 30 hpa. It is only when the vortex is weakened at this level that the tropospheric Canadian vortex begins to wander across the Atlantic.

    So, to be sure if i understand you correctly, the warming of the stratosferical Canadian vortex at 10 hpa creates the un-coupling of the troposferical one?

    It still leaves me with the question why the movements of the stratosferical vortex and the troposferical movements seem to be happening simultaneously.

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    So, to be sure if i understand you correctly, the warming of the stratosferical Canadian vortex at 10 hpa creates the un-coupling of the troposferical one?

    It still leaves me with the question why the movements of the stratosferical vortex and the troposferical movements seem to be happening simultaneously.

    Gravity waves and maybe some rayleigh-taylor instability, to be honest, it is not really somethin uncommon in hydrodynamics.

    Also look at Richtmyer–Meshkov instability. When i wrote this down i started thinkin....this Richtmyer-Meshkov instability is probably of use to predict the behavior of energy releases.

    Edited by iceicebaby
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    Posted
  • Location: Stroud, Gloucestershire
  • Weather Preferences: Extreme!
  • Location: Stroud, Gloucestershire

    10 day ECM 100hpa forecast, now I know very little about all the strat stuff, but in laymens terms does this chart represent the potential for heights to migrate from the Pacific side of the NH over the pole and into the region around Eastern Greenland/Iceland/Northern Scandi?? With a strong southerly Jet pattern??? With a renewed split to the PV?

    Or am I reading totally wrong?

    Posted Image

    Edited by chris55
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    Posted
  • Location: Essex, Southend-On-Sea
  • Weather Preferences: Warm, bright summers and Cold, snowy winters
  • Location: Essex, Southend-On-Sea

    Now I'm new when it comes to the strat towards the end of winter and I know that the strat starts to warm but I noticed this little feature?

    Posted Image

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    Posted
  • Location: Dead Centre of the Vale of Clwyd
  • Weather Preferences: Cold Sancerre.
  • Location: Dead Centre of the Vale of Clwyd

    I don't have anywhere near as much time as I would like to read the excellent posts in here, but I have a nagging question that I'm sure has been answered already - perhaps someone can point me to the answer if so?

    Anyway, I am starting to get to grips with the likely candidates that are associated with an SSW, but SSW's seem to almost pop out of nowhere, relative to the more sedate changes that occur in the drivers of an SSW e.g. QBO and on large scale Rossby stuff. You can set your watch by the QBO and Rossby waves are huge features, so why are warming events not predictable further out?

    The reason I am asking is that prior to the recent colder couple of weeks, there was a clear end result from most NWP output (i.e. cold) but at the time we learned about Shannon Entropy (which I first assumed was the place not the Mathematician) which meant even the larger-scale NWP solutions danced about like nothing I can remember. I guess this was the NWP trying to make sense of the odd input numbers it was being fed from the measured high-altitude hPa data which must already have been feeling the effects of the SSW. The other stand-out feature of NWP modelling this winter was the failed beasterly in December. That really went up to the wire before it vapourised in front of our eyes.

    The question (at last) is, in the same way as the effects of a SSW can take a few weeks to reach the surface, was something happening in the statosphere early December that (unnoticed) heralded the SSW and caused the NWP to get it so wrong? I wonder if there is any correlation between SSW's and a NWP fail 30 days earlier?

    Edited by in the vale
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    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    I don't have anywhere near as much time as I would like to read the excellent posts in here, but I have a nagging question that I'm sure has been answered already - perhaps someone can point me to the answer if so?

    Anyway, I am starting to get to grips with the likely candidates that are associated with an SSW, but SSW's seem to almost pop out of nowhere, relative to the more sedate changes that occur in the drivers of an SSW e.g. QBO and on large scale Rossby stuff. You can set your watch by the QBO and Rossby waves are huge features, so why are warming events not predictable further out?

    The reason I am asking is that prior to the recent colder couple of weeks, there was a clear end result from most NWP output (i.e. cold) but at the time we learned about Shannon Entropy (which I first assumed was the place not the Mathematician) which meant even the larger-scale NWP solutions danced about like nothing I can remember. I guess this was the NWP trying to make sense of the odd input numbers it was being fed from the measured high-altitude hPa data which must already have been feeling the effects of the SSW. The other stand-out feature of NWP modelling this winter was the failed beasterly in December. That really went up to the wire before it vapourised in front of our eyes.

    The question (at last) is, in the same way as the effects of a SSW can take a few weeks to reach the surface, was something happening in the statosphere early December that (unnoticed) heralded the SSW and caused the NWP to get it so wrong? I wonder if there is any correlation between SSW's and a NWP fail 30 days earlier?

    The best answer I can give you is to read the whole thread and that you will see the whole evolving story unfold. It was early December that something occurred in the troposphere that later fed into the stratosphere and led to the SSW!

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    Posted
  • Location: Dead Centre of the Vale of Clwyd
  • Weather Preferences: Cold Sancerre.
  • Location: Dead Centre of the Vale of Clwyd

    The best answer I can give you is to read the whole thread and that you will see the whole evolving story unfold. It was early December that something occurred in the troposphere that later fed into the stratosphere and led to the SSW!

    I was watching the increasing likelihood of a warming event that was first being talked about in November (very early signs of increasing, potentially disruptive wave activity), so I have watched things unfold as much as time allows. Something caused the spectacular easterly prediction failure in Dec which, modelling wise, was a significant event in itself. Was the failure down to a particular feature associated with the (at that time, potential only) upcoming SSW?
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    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    I was watching the increasing likelihood of a warming event that was first being talked about in November (very early signs of increasing, potentially disruptive wave activity), so I have watched things unfold as much as time allows. Something caused the spectacular easterly prediction failure in Dec which, modelling wise, was a significant event in itself. Was the failure down to a particular feature associated with the (at that time, potential only) upcoming SSW?

    I don't think that the SSW was in itself the cause of the failed easterly prediction - however the increase of the vortex strength was likely to contribute to the eventual overriding of the meridional tropospheric pattern that had existed up to that point. There have been mootings that the stratospheric vortex often increases in strength prior to a SSW, but this is just common sense to me. The wave break is always going to have a bigger effect on a stronger vortex.

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    Posted
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet
  • Location: Leeds/Bradford border, 185 metres above sea level, around 600 feet

    To ask my question again - Do you believe that we will see a rebound below average of stratospheric temperatures given the occurance in 2009, 2011 and 2012 following warming..

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    Posted
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.
  • Weather Preferences: Snow and storms
  • Location: Hayward’s Heath - home, Brighton/East Grinstead - work.

    To ask my question again - Do you believe that we will see a rebound below average of stratospheric temperatures given the occurance in 2009, 2011 and 2012 following warming..

    Yes. And would agree that a warmer early spring pattern may be likely.
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