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Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

    Thanks as always @Recretos. It feels like watching an old, respected adversary finally give way after an eternity of lobbying for them to resign.

    I await the higher-resolution version with great anticipation :good:

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    Welcome to the latest stratospheric temperature watch thread.   A bit later this year with a new thread – but better late than never! It is now the 7th winter stratospheric temperature watch threa

    I wonder, do we have a slow burner ? A slow burner that perhaps leads to a more assured route to a warming event in January ? The pattern as of yesterday and for the next 7 days is within the env

    Stratosphere forecasting is probably just as complicated as traditional weather forecasting and when you break things down there are both positive and negative factors which will affect whether a stra

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    Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)


    This vid from the Met Office talks in very general terms but it's a neat way to visualise the process by which warming occurs and then propagates downward during a successful event.

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    Posted
  • Location: Catchgate, Durham,705ft asl
  • Location: Catchgate, Durham,705ft asl

    -70 m/s near the top of the strat at day 7.Seriously?

     

    ecmwfzm_u_f168.thumb.gif.49c3bc65e72172decmwf2f168.thumb.gif.73c5042aeb44ada7fbe

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    Posted
  • Location: Wellseborne, Warwickshire
  • Weather Preferences: Southerly tracking low pressure in winter. Hot and thundery in the summer
  • Location: Wellseborne, Warwickshire
    57 minutes ago, Cloud 10 said:

    -70 m/s near the top of the strat at day 7.Seriously?

     

    ecmwfzm_u_f168.thumb.gif.49c3bc65e72172decmwf2f168.thumb.gif.73c5042aeb44ada7fbe

    Wow that's some reversal , the models haven't picked up the downwelling yet but Iv no doubt this should blow the vortex apart ? Could be a very interesting late March period !

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    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
    On ‎27‎/‎02‎/‎2016 at 8:40 AM, Cloud 10 said:

    Certainly full steam ahead from yesterday's ECM.

     

    -60m/s higher up in the strat and downwelling by the look of it.:shok:

     

    ecmwfzm_u_f240.thumb.gif.6a890952beee3bbfluxes.thumb.gif.f6d3c0c790f845b50dac519

    Yes apart from the fact its too late, it looks a near perfect SSW to me, of course it remains to be seen what happens lower down.

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    Posted
  • Location: Stroud, Gloucestershire
  • Weather Preferences: Extreme!
  • Location: Stroud, Gloucestershire

    Its never to late for a snowflake! And seeing as I haven't seen one this winter, a few in spring my suffice.

    Though it will be fascinating to see how this late SSW does actually end up affecting our weather, certainly very interesting.

    Edited by chris55
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    Posted
  • Location: Wakefield, West Yorkshire
  • Weather Preferences: Anything except blazing hot summers!
  • Location: Wakefield, West Yorkshire

    Surprising that the SSW is occurring right down (according to Ed on Twitter) and after a busy winter on this thread, there's been no posts for 3 days! :cc_confused:

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    Posted
  • Location: NorthWest Central London, United Kingdom
  • Weather Preferences: Cold and Snowy Winters, Hot and Sunny Summers - Never Mild!
  • Location: NorthWest Central London, United Kingdom
    1 hour ago, Paul_1978 said:

    Surprising that the SSW is occurring right down (according to Ed on Twitter) and after a busy winter on this thread, there's been no posts for 3 days! :cc_confused:

    As someone has already answered this question previously in this forum, I will reiterate., I think the lack of comments on the SSW has to do with the fact that many members wanted a cold/snowy winter and one way to achieve this in the UK was through the route of an SSW. Seeing how winter is now over, many have lost interest altogether (Me included). The SSW is taking affect now, but many assume that the after-effects of it will not be cold or snowy, therefore, no comments on it and lack of excitemnet; thats it in a nutshell. :sorry:

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    Posted
  • Location: Irlam
  • Location: Irlam
    6 minutes ago, mpkio2 said:

    As someone has already answered this question previously in this forum, I will reiterate., I think the lack of comments on the SSW has to do with the fact that many members wanted a cold/snowy winter and one way to achieve this in the UK was through the route of an SSW. Seeing how winter is now over, many have lost interest altogether (Me included). The SSW is taking affect now, but many assume that the after-effects of it will not be cold or snowy, therefore, no comments on it and lack of excitemnet; thats it in a nutshell. :sorry:

    I'm afraid that is just poor. We should be looking at this and see what the consequences if any, to aid our understanding of future SSW events. 

    Should look beyond just looking for cold and snow.

    Edited by Weather-history
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    Posted
  • Location: NorthWest Central London, United Kingdom
  • Weather Preferences: Cold and Snowy Winters, Hot and Sunny Summers - Never Mild!
  • Location: NorthWest Central London, United Kingdom
    25 minutes ago, Weather-history said:

    I'm afraid that is just poor. We should be looking at this and see what the consequences if any, to aid our understanding of future SSW events. 

    Should look beyond just looking for cold and snow.

    Oh don;t get me wrong; I completly understand the importance of further research and observations on cutrrent weather-patterns that are currently unfolding (Or will unfold in the future to come,) and how it affects are weather. I'm just stating why there is the lack of comments on the SSW at the moment. :good:

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    Posted
  • Location: Manchester
  • Location: Manchester
    5 hours ago, Dennis said:

    The new SSW begin  March is going through many air-layers

    86.jpg

    So far the tropospheric models are not showing any arctic outbreak for us. We look like missing out to the east.

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    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
    On ‎05‎/‎03‎/‎2016 at 0:48 PM, Weather-history said:

    I'm afraid that is just poor. We should be looking at this and see what the consequences if any, to aid our understanding of future SSW events. 

    Should look beyond just looking for cold and snow.

    I do se your point and Ed's in the MOD but given his username, I am sure that the reason he got interested in the Stratosphere in the first place (and indeed pioneered the science on here over the last 7 years or so)  was his love for blocking patterns in winter. It may well be an interesting science even if the strat had no effect whatsoever on Trop-Surface conditions but there's nothing wrong with having personal reasons for being interested in science, Teachers mottos at school should always be  'Science is fun' and 'Make learning interested.

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    The strongest 10mb 60°N wind reversal in the MERRA data is -31.08 m/s from 28/01/2009 and both ECMWF and GEOS have been forecasting stronger reversals than this with yesterday's ECM giving -32 m/s for 15/03 and GEOS with -33.52 m/s for 14/03.

    The reversal is forecast to propagate down quite well with ECM having reversals at 20mb on 08/03, 30mb on 10/03 and 50mb on 13/03 while the GEOS has 30mb on 11/03 (no 20mb data), 50mb on 13/03 and 70mb on 14/03

    This latest GEOS is more bullish than the ECM at this stage with 150mb winds down to 4.67 m/s on 14/03 and this is where things get interesting as this level, of those available, has the closest correlation with the AO though of course it can either be affected from above or below i.e. may influence the troposphere or be a reflection of it.

    Anyway, the maximum daily NCEP AO for the 64 March days with 150mb winds below 5 m/s is 0.121 on only the one day in positive territory, with a mean value of -2.529

    The ECM value of around 10 m/s is not much different than normal and gives a neutral/marginally -ve AO.

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    Posted
  • Location: Wakefield, West Yorkshire
  • Weather Preferences: Anything except blazing hot summers!
  • Location: Wakefield, West Yorkshire
    2 hours ago, Interitus said:

     

    Interesting stuff @Interitus. Here is the Met Office report for March 1980:

    http://www.metoffice.gov.uk/media/pdf/4/b/Mar1980.pdf

     

    Edit: ooops I see you've already included that link. 

    Edited by Paul_1978
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    Posted
  • Location: Surrey and SW France.
  • Location: Surrey and SW France.

    @Bring Back1962-63 posted the latest Cohen blog in the model thread.

    http://www.aer.com/science-research/climate-weather/arctic-oscillation

    I'm confused by the following passage ....

    The winds have already reversed direction in the polar stratosphere (the winds have changed direction from coming out of the west to coming out of the east).  According to our understanding of meteorology, the atmospheric vertical energy transfer should be impossible once the wind direction reverses and yet both the Global Forecast System (GFS) and European Centre for Medium Range Weather Forecasting (ECMWF) models predict more vertical energy transfer for this week.

    That does not (to me) correspond with what Adam Scaife is saying in the video on previous page - it is a gradual stage process as the reversal burrows down. Can anyone please clarify if I'm getting my waves and wave activity flux mixed up.  

    Like I did, he thinks March SSWs are rare but thanks to @Interitus that thought was quickly dispelled. Atmosphere physics is not my strong point but I do know my uncharted from unchartered. :oops:

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    6 hours ago, Nouska said:

    @Bring Back1962-63 posted the latest Cohen blog in the model thread.

    http://www.aer.com/science-research/climate-weather/arctic-oscillation

    I'm confused by the following passage ....

    The winds have already reversed direction in the polar stratosphere (the winds have changed direction from coming out of the west to coming out of the east).  According to our understanding of meteorology, the atmospheric vertical energy transfer should be impossible once the wind direction reverses and yet both the Global Forecast System (GFS) and European Centre for Medium Range Weather Forecasting (ECMWF) models predict more vertical energy transfer for this week.

    That does not (to me) correspond with what Adam Scaife is saying in the video on previous page - it is a gradual stage process as the reversal burrows down. Can anyone please clarify if I'm getting my waves and wave activity flux mixed up.  

    Like I did, he thinks March SSWs are rare but thanks to @Interitus that thought was quickly dispelled. Atmosphere physics is not my strong point but I do know my uncharted from unchartered. :oops:

    Yes the reversal 'burrows' down while the waves are propagating up from the troposphere but can't pass through the reversed layer - hence we don't see wave activity in the summer when easterly winds prevail in the polar stratosphere. The GFS wave activity flux (WAFz) chart on the Cohen blog is labelled as averaged between 40-80°N - clearly the wind isn't reversed at all these latitudes and even where it is reversed at a particular height and latitude it is a zonal mean and may still contain a proportion of westerly flow. Seems to be a surprisingly simple mistake by JC there.

    Regarding the rarity of March SSW, many influential studies which explore the frequency of SSW exclude final warmings - eg Charlton & Polvani 2007 -

    Quote

    Finally, it is important to highlight that only midwinter warmings are considered in this study. To ensure this, cases where the zonal mean zonal winds become easterly but do not return to westerly for at least 10 consecutive days before 30 April are assumed to be final warmings, and as such are discarded. This criterion ensures that following SSWs, a coherent stratospheric vortex is reestablished

    http://www.columbia.edu/~lmp/paps/charlton+polvani-JCLIM-2007.pdf

    This obviously reduces the number of March SSW and under this scheme this current likely strongest SSW on record may not be one after all by the end of next month.

    Edited by Interitus
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    Just to add that the ECM analysis chart from Berlin for yesterday has 10 mb reversal at -22 m/s which would be the strongest easterly in March in the MERRA data which goes back to 1979 and makes it 5th strongest SSW (so far) behind -

    24/01/2009 peak reversal -31.08 m/s

    21/01/2006 peak -26.15 m/s

    23/01/1987 peak -23.46 m/s

    15/12/1998 peak -22.88 m/s

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    Posted
  • Location: Hoyland,barnsley,south yorkshire(100m asl)
  • Weather Preferences: severe storms,snow wind and ice
  • Location: Hoyland,barnsley,south yorkshire(100m asl)

    Whoooooshka!!!:shok:

    30 and 10 hpa

    pole30_nh.thumb.gif.92ecb584a0ae3a90886cpole10_nh.thumb.gif.875b75aa833a8e29c209

     

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    Posted
  • Location: Hoyland,barnsley,south yorkshire(100m asl)
  • Weather Preferences: severe storms,snow wind and ice
  • Location: Hoyland,barnsley,south yorkshire(100m asl)

    Through the roof!:D

    yesterday'spole30_nh.thumb.gif.767f40b97d06b30e214atoday's56e00d829ea65_pole30_nh1.thumb.gif.d9fcf

    although the 10hpa is on it's way down but never the less it's still impressive,it's a shame it has happened a bit late in the season,let's see what transpires from this.

    pole10_nh.thumb.gif.608a04b7fa47b13a94a0

    there is curtainly some eyecandy from the latest control run,with a reversal there

    gensnh-0-1-324.thumb.png.21b6b014d73fcc0

     

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    Posted
  • Location: Hoyland,barnsley,south yorkshire(100m asl)
  • Weather Preferences: severe storms,snow wind and ice
  • Location: Hoyland,barnsley,south yorkshire(100m asl)

    Gavin has made a vid on this upcoming warming which i posted above,he explains it in good detail,better than i could anyway:)

    we just need the ball to fall in the right park now and i am hoping for a last wintry blast of the winter and then move on,take a look.

     

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    Posted
  • Location: Slovenia, Central Europe 1050m ASL
  • Location: Slovenia, Central Europe 1050m ASL

    Still too much emphasis on the temperature and too little on the other energies involved. Were all this really worthy of hype in terms of super effects, I would be among the first to jump the train. But since its not, that is the reason for my lack of activity in here.

    Edit:
    I really do hope that this season was a very good lesson for us all, how each SSW is a unique feature and we cannot handle SSWs  with "Wikipedia-ish" approach. One thing that Mr. Judah Cohen also needs to learn, with all due respect. Regardless of the impressive temperature numbers, SSWs, are simply not just temperature-only features, and much more things are involved in the whole process that can make or break a winter period. 

    Regards. :)

    Edited by Recretos
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