Jump to content
Cold?
Local
Radar
Snow?

Stratosphere and Polar Vortex Watch


Recommended Posts

Posted
  • Location: Clayton-le-Woods, Chorley, Lancs
  • Weather Preferences: Snow
  • Location: Clayton-le-Woods, Chorley, Lancs

     

    Link to post
    Share on other sites
    Spotted a post you think may be an issue? Please help the team by reporting it.
    • Replies 3.9k
    • Created
    • Last Reply

    Top Posters In This Topic

    Top Posters In This Topic

    Popular Posts

    Some useful tropospheric developments upcoming which are likely to have stratospheric impacts towards the end of November and more particularly into December. A strong convectively coupled tropic

    so after many days the GFS & FNMOC & canadian finally now follow the Euro with 44 out 64 Members with a split at day 9- The ECM is day 8. We will call it - SSW & Split for 1st Ja

    For all that watch the zonal winds. Let me urge you to look at the geopotential heights more. At least as far as weakening/strengthening trends go. Because as the polar vortex cries for help, you migh

    Posted Images

    Posted
  • Location: Clayton-le-Woods, Chorley, Lancs
  • Weather Preferences: Snow
  • Location: Clayton-le-Woods, Chorley, Lancs

     

    Link to post
    Share on other sites
    Posted
  • Location: Clayton-le-Woods, Chorley, Lancs
  • Weather Preferences: Snow
  • Location: Clayton-le-Woods, Chorley, Lancs

     

    Link to post
    Share on other sites
    Posted
  • Location: Coniston, Cumbria 90m ASL
  • Weather Preferences: wintry
  • Location: Coniston, Cumbria 90m ASL
    Posted
  • Location: st albans
  • Location: st albans

    Gfs op 12z and eps are a few m/s away from a technical ssw day 16. Would assume that will follow before year end but without the wave 2 to follow we would see the vortex re strengthen ....... good news is gems are now finding a cut off Alaskan ridge by end week 2  with eps and gefs both very amplified on a mean upper ridge same area. 

    I wonder how this would play out - with n scandi ridging continuing to be evident in the extended trop means, a quick trop response that splits the trop looks pretty straightforward though the renewed ne Canadian vortex segment looks pretty big by then and a fast break apart of the vortex runs the risk of a fragment being discarded to places we may be so keen to see it reside  ......... it’s hapoened before ..... the good news is that we wouldn’t yet be half way through winter 

    • Like 4
    Link to post
    Share on other sites
    Posted
  • Location: Beccles, Suffolk.
  • Weather Preferences: Thunder, snow, heat, sunshine...
  • Location: Beccles, Suffolk.
    6 minutes ago, Glacier Point said:

    Ticking along nicely. Big convective anomaly traversing through the Indian Ocean with clear extratropical impacts.

    Best analogues early December 1965 and early January 2004 for a strong displacement type warming,

    Day 1: 10 hPa

    2008964279_stratday1.thumb.gif.b46b8b14aebfc0f289d05d7551e91ba7.gif

    By day 26 indication of split vortex (and therefore a sustained event):

    750037027_stratday26.thumb.gif.e10d33a036f14b8e30acf470e183e25a.gif

    Tropospheric impacts start day 12 on these analogues (not allowing for fast propagation waves), running through day 30. Day 16 here for reference:

    1822339912_stratday16z500.thumb.gif.14ade5ed7c0b97eff936ffb2509b1243.gif

    If there were a split vortex, trop impacts would continue well beyond this.

    All of this occurring when tropospheric drivers signalling low pressure in the Atlantic and pressure rise over Greenland for January. The key issues will be: getting cold air embedded over Europe during the initial stages, and not to much high pressure over North Africa and Iberia and sufficient upper level flow through central Europe.

    Interestingly, 1984/5 continues to resonate here. MJO evolution that year suggests another opportunity for a strat event during February.

    diagram_40days_forecast_GEFSBC_member.thumb.gif.0f6c8258f3dd981afaf87dea5bbd6232.gif198410.phase.90days.gif.small.thumb.gif.340fbcb0d486247fc9227a707e6690af.gif

    198501.phase.90days.gif.small.thumb.gif.fc4827fb6a686417119cfc9872fbc8c7.gif

    And here, just in case anyone-else has forgotten the winter of '66, is the archive chart for January 12th...Happy Birthday to me!

    GFS Archive Image

     

    • Like 8
    Link to post
    Share on other sites
    Posted
  • Location: Longton, Stoke-on-Trent.
  • Location: Longton, Stoke-on-Trent.
    3 hours ago, Glacier Point said:

    Ticking along nicely. Big convective anomaly traversing through the Indian Ocean with clear extratropical impacts.

    Best analogues early December 1965 and early January 2004 for a strong displacement type warming,

    Day 1: 10 hPa

    2008964279_stratday1.thumb.gif.b46b8b14aebfc0f289d05d7551e91ba7.gif

    By day 26 indication of split vortex (and therefore a sustained event):

    750037027_stratday26.thumb.gif.e10d33a036f14b8e30acf470e183e25a.gif

    Tropospheric impacts start day 12 on these analogues (not allowing for fast propagation waves), running through day 30. Day 16 here for reference:

    1822339912_stratday16z500.thumb.gif.14ade5ed7c0b97eff936ffb2509b1243.gif

    If there were a split vortex, trop impacts would continue well beyond this.

    All of this occurring when tropospheric drivers signalling low pressure in the Atlantic and pressure rise over Greenland for January. The key issues will be: getting cold air embedded over Europe during the initial stages, and not to much high pressure over North Africa and Iberia and sufficient upper level flow through central Europe.

    Interestingly, 1984/5 continues to resonate here. MJO evolution that year suggests another opportunity for a strat event during February.

    diagram_40days_forecast_GEFSBC_member.thumb.gif.0f6c8258f3dd981afaf87dea5bbd6232.gif198410.phase.90days.gif.small.thumb.gif.340fbcb0d486247fc9227a707e6690af.gif

    198501.phase.90days.gif.small.thumb.gif.fc4827fb6a686417119cfc9872fbc8c7.gif

    Thanks, GP.

    Any idea on a rough timescale/date for tropospheric impacts this winter?

    You predicted major strat warming around the 26th of December, and this is now showing up on the models. Do you still expect further warming to deliver a split PV? The first warming appears to produce a displacement (not often great for NW Europe) but the GFSP is now indicating further warming after this.

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: Clayton-le-Woods, Chorley, Lancs
  • Weather Preferences: Snow
  • Location: Clayton-le-Woods, Chorley, Lancs
    2 hours ago, Glacier Point said:

    So timing looks like this:

    Stratospheric (displacement) warming 27-29th December. First tropospheric response would on that basis be around 10th January, peaking on first wave response 15th-25th January. Second wave early to mid Feb, potentially very interesting if split vortex occurs.

    Bear in mind, this doesn't take into account troposheric forcing. MJO cycles suggest mid latitude ridges early January, but GWO lagged impact of westerly inertia being deposited as of 9th December suggests more -NAO variant to this. Either way here, January and early February hold the greatest cold weather potential for this winter (and has been the case for some time).

     

    So right in the heart of Winter for maximum impact ??

    • Like 3
    Link to post
    Share on other sites
    Posted
  • Location: County end Oldham 202 m Above sea level
  • Location: County end Oldham 202 m Above sea level
    16 minutes ago, Weather-history said:

     

    Sounds interesting... MV getting quite excited!!

    Link to post
    Share on other sites
    Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

    npst30.png

    By this stage, is the vortex far east enough that it ceases to benefit Atlantic trough intensification, instead encouraging Sceuro trough development? I'm unsure as to where exactly the positive vorticity translates down from the 30 hPa level.

    If this is true then that could combine in favourable ways with the tropical forcing in terms of cold air advection across Europe and toward the UK. Across too, if we're lucky enough.

    • Like 3
    Link to post
    Share on other sites
    Posted
  • Location: Wakefield, West Yorkshire
  • Weather Preferences: Anything except blazing hot summers!
  • Location: Wakefield, West Yorkshire
    2 minutes ago, northwestsnow said:

    Sounds interesting... MV getting quite excited!!

    Sounds like it’s happening!!

    • Like 1
    Link to post
    Share on other sites
    Posted
  • Location: County end Oldham 202 m Above sea level
  • Location: County end Oldham 202 m Above sea level
    8 minutes ago, Paul_1978 said:

    Sounds like it’s happening!!

    Hope so mate!!

    I'm easily excitable so to see someone like MV getting excited is good news.. ?

    Link to post
    Share on other sites
    Posted
  • Location: Manchester Deansgate.
  • Weather Preferences: Heavy disruptive snowfall.
  • Location: Manchester Deansgate.
    1 hour ago, Singularity said:

    npst30.png

    By this stage, is the vortex far east enough that it ceases to benefit Atlantic trough intensification, instead encouraging Sceuro trough development? I'm unsure as to where exactly the positive vorticity translates down from the 30 hPa level.

    If this is true then that could combine in favourable ways with the tropical forcing in terms of cold air advection across Europe and toward the UK. Across too, if we're lucky enough.

    TBH, regardless of what happens further into January, to my fairly untrained eye, there looks to me to be no logical reason as to why we can't get a trop induced cold / snow event around late December / early Jan, even allowing for my comparable lack of knowledge with regard to AAM and the GWO, see GP's second post.

    • Like 3
    Link to post
    Share on other sites
    Posted
  • Location: Cambridge, UK
  • Weather Preferences: Anything out of the ordinary!
  • Location: Cambridge, UK

    Interestingly, Chris Fawkes has interpreted the warming and displacement translating to mild wet and windy for the UK. Make of that what you will!!

    Link to post
    Share on other sites
    Posted
  • Location: Ludgershall, Wiltshire
  • Location: Ludgershall, Wiltshire
    8 minutes ago, mb018538 said:

    Interestingly, Chris Fawkes has interpreted the warming and displacement translating to mild wet and windy for the UK. Make of that what you will!!

    Well, he is expecting a mild and wet winter.

    Link to post
    Share on other sites
    Posted
  • Location: st albans
  • Location: st albans
    9 minutes ago, mb018538 said:

    Interestingly, Chris Fawkes has interpreted the warming and displacement translating to mild wet and windy for the UK. Make of that what you will!!

    I guarantee that at some point beyond any SSW, there will be mild, wet and windy weather for the uk  .............

    Link to post
    Share on other sites
    Posted
  • Location: Burton-on-Trent
  • Location: Burton-on-Trent
    2 hours ago, mb018538 said:

    Interestingly, Chris Fawkes has interpreted the warming and displacement translating to mild wet and windy for the UK. Make of that what you will!!

    Strange. I can understand going for wet and mild in the next 3 weeks as the vortex is pushed towards our side of the globe, but some of those 300h+ charts show a noticeable lack of vortex over Canada and Greenland.

    Link to post
    Share on other sites
    Posted
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)
  • Location: Caterham-on-the-hill, Surrey, 190m asl (home), Heathrow (work)

    Even stronger signal from GEFS for zonal wind reversal now, only a few members not going for it by end of December.

    1127879645_u_65N_10hpa_gefs(2).thumb.png.494b87e6a85d7392859588581abb8126.png

    ... compare this to yesterday, albeit less a day:

    1509854486_u_65N_10hpa_gefs(1).thumb.png.8a62335c9c1ddbb554518a735dbffa03.png

    Edited by Nick F
    • Like 8
    • Thanks 1
    Link to post
    Share on other sites
    Posted
  • Location: New Forest (Western)
  • Weather Preferences: Fascinated by extreme weather. Despise drizzle.
  • Location: New Forest (Western)

    The strength of reversal seems exceptional for a displacement type event. Usually, they don't manage to shift the vortex so far south, hence the historical analysis of displacements as a whole looking so mediocre for the UK and NW Europe in terms of cold weather prospects.

    If this event really is to be on another level, then using the historical stats for displacements as a guide is likely to prove to be a fool's errand. Fascinating times are with us... yet again in 2018!

    • Like 5
    • Thanks 1
    Link to post
    Share on other sites
    Posted
  • Location: Royston , Herts
  • Weather Preferences: SNOW
  • Location: Royston , Herts
    18 minutes ago, Singularity said:

    The strength of reversal seems exceptional for a displacement type event. Usually, they don't manage to shift the vortex so far south, hence the historical analysis of displacements as a whole looking so mediocre for the UK and NW Europe in terms of cold weather prospects.

    If this event really is to be on another level, then using the historical stats for displacements as a guide is likely to prove to be a fool's errand. Fascinating times are with us... yet again in 2018!

    Yes @Singularity I was thinking the same , if it’s only a displacement why is there such a big reversal showing ? Not that I’m complaining , the bigger the better . Like you say could be a different ssw to what we’ve seen before ? 

    • Like 2
    Link to post
    Share on other sites
    Guest
    This topic is now closed to further replies.
    ×
    ×
    • Create New...