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Stratosphere watch 2018/19

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  • Registered Users Posts: 1,976 ✭✭✭Artane2002


    The GFS Para 12z splits the vortex and practically destroys it!


  • Registered Users Posts: 17,797 ✭✭✭✭hatrickpatrick


    Not a good few runs from the GFS, either op or FV3 - however, apparently it's quite the outlier:

    https://twitter.com/TradeWpower/status/1076456163271692288

    Cautiously optimistic.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Well CFSv2 continues to show the SSW event occurring (and possibly a split) with the signal becoming stronger for -NAO.

    https://twitter.com/SimonLeeWx/status/1076486230425174018


  • Registered Users Posts: 1,976 ✭✭✭Artane2002


    The ECM is showing a split again. The GFS and GFS Para aren't showing it. This Mexican standoff is getting really tiring at this stage... fingers crossed that the ECM humiliates the GFS/GFS(P)


  • Registered Users Posts: 16,550 ✭✭✭✭nacho libre


    Artane2002 wrote: »
    The ECM is showing a split again. The GFS and GFS Para aren't showing it. This Mexican standoff is getting really tiring at this stage... fingers crossed that the ECM humiliates the GFS/GFS(P)

    I would love to be able see the glosea5 model at this time. I have read that the ECM is more reliable when it comes to events in the stratosphere thread. They are probably in meltdown over on Netweather due to the latest GFS run.


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  • Moderators, Science, Health & Environment Moderators Posts: 4,466 Mod ✭✭✭✭mickger844posts


    I would always rather have the ECM on side in this type of scenario. GFS can be a bit baffling at times with its outcomes. A SSW very much ON at this stage.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Still lots of flips and flops and model disagreement.

    https://twitter.com/jhomenuk/status/1076893495896522752


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen




  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Hope everybody had a wonderful Christmas, I certainly did.

    An exercise I decided to do this morning (after taking a break yesterday) was looking at my Winter analogue years and see which years had a SSW in them. The years in the analogue were 1941-42, 1963-64, 1979-80, 1994-95, 1996-97, 2010-11, 1901-02, 1940-41, 1968-69, 1987-88, 1995-96, 2001-02, 2008-09 and 1990-91.

    Stratospheric records only go back to the 1950s so can disregard the 1940s years and 1901-02. The years with a SSW were 1979-80 (Feb), 2001-02 (Dec/Jan), 2008-09 (Jan), 1968-69 (Nov/Mar). Only 1 of these was a split - January 2009. Reanalysis of Jan and Feb below.

    January shows some high latitude blocking especially over Greenland with a trough centred in the Atlantic. Not a classic chart to delivering cold to the UK and Ireland but possibility of some cold snaps. The blocking would need to be stronger or more extensive for severe cold. Nearly a battleground scenario between the Atlantic and the blocking.

    0U39ZW7.png

    February is quite similar but different positioning. The blocking is more over to North America giving a very cold month for them but the placement of the below average heights look favourable for cold too in the UK/Ireland. Keep in mind, February 1969 is likely skewing this.

    jAy89xz.png

    If we were to break this down further and consider ENSO, well 2008-09 was weak La Nina so can count that out. 2001-02 was ENSO neutral so can leave that aside. 1968-69 and 1979-80 were both El Nino events, the former moderate whilst the latter weak.

    1968-69 became severely cold in February with some really heavy snowfalls after a mild January due to a western based -NAO. 1979-80 had a fairly chilly January but was otherwise mild with a very wet December for some.

    Keep in mind, this is an experimental exercise. Both years had different SSW events to what is likely to evolve now. 1968-69 had the displacement in November and March - also the Canadian Warming in November whilst 1979-80 had the displacement in February.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Zonal winds at 60N 10hPa set to reverse in a few days now according to the GEFS displacing the vortex away from the pole (wave 1) which is currently in progress, have some reasonable agreement now on it occurring. After this initial reversion, the zonal winds go a bit above 0 m/s (reversions are very short events) but the GFS predicts a second warming (wave 2) to occur which could reverse the zonal winds a second time much like last February though amplification not as intense as February and I do not expect them to reverse again currently. This wave 2 is looking like a split according to GFS and ECM.

    Rmc2K34.png

    https://twitter.com/Forecas55175638/status/1078257392746401792

    Here's a very recent blog post by Simon Lee that I'd recommend you to read showing that not all SSW events are equal in impact/evolution and some very useful information too on this current warming.

    https://simonleewx.com/2018/12/27/not-all-ssws-were-created-equal/


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  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen




  • Closed Accounts Posts: 4,431 ✭✭✭Mortelaro


    A daughter vortex by the way slipping south into and then from Scandinavia is exactly what you need to replicate Nov Dec 2010,was that a cold one ??
    Needs to head south though not south east,the dynamics should favour it heading south or southwest?
    But we do not and cannot know until maybe the end of next week when more strat affect options appear
    None will be right,rules of FI will still apply but there should be better pointers than now if you get me?


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    The zonal winds at 60N 10hPa are set to reverse in just two days away and there continues to be a signal for a succeeding warming occurring which will reverse the zonal winds again and more dramatically by current guidance. This is likely to involve a split of the Polar Vortex.

    0d12LYC.png

    https://twitter.com/Forecas55175638/status/1079027467539677184


  • Registered Users Posts: 721 ✭✭✭Defaulter1831


    sryanbruen wrote: »
    The zonal winds at 60N 10hPa are set to reverse in just two days away and there continues to be a signal for a succeeding warming occurring which will reverse the zonal winds again and more dramatically by current guidance. This is likely to involve a split of the Polar Vortex.

    0d12LYC.png

    https://twitter.com/Forecas55175638/status/1079027467539677184

    Thanks Sryan :) My daffodill flower heads are 7 inches above the ground! Best get some winter in winter or if not we'll have serious growth of srubbery etc and a late cold spell will burn the lush growth. Like after Feb and March 1998 and the frosts around 10th April and the Good Friday agreement, -5C in parts, burnt shrubs, foliage etc an horrendous brown/black.

    I have only one word 'Hurray!!'.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen




  • Registered Users Posts: 599 ✭✭✭Captain Snow


    Slightly higher then expected. :)

    1zva8m9.jpg


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    Split is likely to involve the PV split into three daughter vortices based on the latest guidance.

    https://twitter.com/judah47/status/1079363351677976576

    More good signs.

    https://twitter.com/judah47/status/1079364827355717632


  • Registered Users Posts: 17,797 ✭✭✭✭hatrickpatrick


    @Sryan, I'm not sure if I'm reading these charts correctly, but this graphic would seem to imply a split of the entire vortex from top to bottom by Jan 6th:

    geos_nh-vort3d_20181228_f216_rot000.png

    Or are these charts confined exclusively to the strat? It's difficult to tell based on the scale used just how far down the modelling goes into the troposphere.


  • Registered Users Posts: 8,219 ✭✭✭Gaoth Laidir


    @Sryan, I'm not sure if I'm reading these charts correctly, but this graphic would seem to imply a split of the entire vortex from top to bottom by Jan 6th:

    geos_nh-vort3d_20181228_f216_rot000.png

    Or are these charts confined exclusively to the strat? It's difficult to tell based on the scale used just how far down the modelling goes into the troposphere.

    It goes to the surface but extends to around 37 km (1200 K potential temperature). For reference, 400 K is 15 km and 800 K is 30 km.


  • Registered Users Posts: 599 ✭✭✭Captain Snow


    Who knew SSW would be the new Model Watching cause frankly Model Watching mess,s with your sanity.....:p


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  • Registered Users Posts: 9,230 ✭✭✭sdanseo


    Who knew SSW would be the new Model Watching cause frankly Model Watching mess,s with your sanity.....:p

    If anything with me it's caused model ignorance. Or maybe that was Christmas.

    Still not interested in any model output until w/c 7th, will start looking at it in earnest then.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    So 29th December was the peak for the warming at 10hPa, we now wait and see how it will fare at 30hPa.

    v6gYPCm.gif

    6z6QpsD.gif


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen




  • Registered Users Posts: 5,008 ✭✭✭mikeecho


    Be kind.

    Complete noob / idiot here.

    What will this stratospheric warming have in store for us.

    And how long before we know if it's gonna cause freezing temps. (Not even gonna ask about snow)

    This forum was invaluable to me this year, I was able to look like a complete idiot buying salt / grit and a snow shovel, getting the oil tank filled, warning friends and family, and getting laughed at.

    Who had the last laugh.. use boardsies


  • Registered Users Posts: 9,230 ✭✭✭sdanseo


    mikeecho wrote: »
    Be kind.

    Complete noob / idiot here.

    What will this stratospheric warming have in store for us.

    And how long before we know if it's gonna cause freezing temps. (Not even gonna ask about snow)

    This forum was invaluable to me this year, I was able to look like a complete idiot buying salt / grit and a snow shovel, getting the oil tank filled, warning friends and family, and getting laughed at.

    Who had the last laugh.. use boardsies

    I actually remember you saying similar last year. Wasn't it you who got strange looks in Argos buying the shovel? (To be fair, probably more than just you if so :pac: )

    Unfortunately the honest answer for another week or so is

    how-long-is-a-piece-of-string.jpg

    My gut says we will get a cold blast, probably longer in duration than Emma but not as severe. Based on other posters commenting that had last year's event happened in January it may have become more embedded.

    By not as severe I mean meteorologically. 1cm of snow every day for a month, for example, will cripple Ireland. We don't prepare even with now 3 major events in less than a decade. (cue videos of Garda cars going sideways, gangs of lads having to push a fire engine and an Ambulance with snow socks)


  • Registered Users Posts: 5,008 ✭✭✭mikeecho


    It was me in Argos, getting stupid looks,

    I walked across the car park with a snow shovel, while the local hard men were wearing t shirts


  • Registered Users Posts: 599 ✭✭✭Captain Snow


    Brief Summary:

    Sudden Stratospheric Warming underway, mid/late January could see some serious winter weather across a large part of Europe.....

    http://www.severe-weather.eu/long-range-2/sudden-stratospheric-warming-underway/


    The mid-stratosphere temperature over the pole is more than 65 °C warmer than in a normally strong polar vortex situation.

    20p38cj.png


    The strong ridging over the pole in combination with the warming will be strong enough to break down (split) the polar vortex in half, with the stronger half remaining over the European sector and the smaller vortex over North America.

    2i20ao8.png


    Looking at the NOAA/CPC analysis, the whole process has begun around a week ago and is slowly progressing from the stratosphere down into the troposphere. That is what we want to see, the progression and impact from the stratosphere down into the troposphere.

    15foyae.png


    We can expect to see colder air move into Europe in the next 2-3 weeks, with more proper winter weather and even snow for eastern and central Europe, that could continue into February.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen


    This is nearly an official SSW, mean zonal wind speed at 60N 10hPa is currently at 0 m/s.


  • Registered Users Posts: 13,477 ✭✭✭✭sryanbruen




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  • Registered Users Posts: 16,550 ✭✭✭✭nacho libre


    orthographic=-0.27,86.88,205


    Dv1wkMyUwAA4_0w.jpg



    Amy H Butler @DrAHButler

    😁 65 of 65 ensemble members with splits by Jan 3 (wind reversal should occur before then).


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