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What the heck is the polar vortex, anyway?


knocker
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Posted
  • Location: Camborne
  • Location: Camborne

    Ever since the events of last winter in the US the term 'Polar Vortex' has almost become as common as  confetti at a wedding but is it being used correctly?

     

    The definition according to the AMS updated in January.

     

     

    polar vortex
    A planetary-scale mid- to high-latitude circumpolar cyclonic circulation, extending from the middle troposphere to the stratosphere. The Northern Hemisphere vortex often features two centers—one near Baffin Island and the other over northeast Siberia—with analogous circumpolar asymmetry atypical in the Southern Hemisphere. The westerly airflow is largely a manifestation of the thermal wind above the polar frontal zone of middle and subpolar latitudes. The vortex is strongest during the winter in the upper troposphere and stratosphere when the pole-to-equator temperature gradient is strongest. The stratosphere component of the circulation may be referred to separately as the “polar stratospheric vortex.†In summer, the strongest westerly circulation is largely confined to the troposphere, and the polar stratospheric vortex reverses in the upper stratosphere because of solar heating during the polar day.
    Reference: Simmons, A., M. Hortal, G. Kelly, A. McNally, A. Untch, and S. Uppala, 2005: ECMWF analyses and forecasts of stratospheric winter polar vortex breakup: September 2002 in the Southern Hemisphere and related events. J. Atmos. Sci., 62, 668–689. [

     

    And now the arguments have started once more with the forecast of a very unusual weather event set to take place in the US next week.

     

    Cold Snap in July: Will the Real Polar Vortex Please Stand Up?

    http://mashable.com/2014/07/11/polar-vortex-in-july-explained/

    Edited by knocker
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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    so now we have an argument of what is or what is not the polar vortex!

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    Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

    A lot of fuss over nothing really.

    When all said and done it's just a deep upper trough something we see often around the UK.

    It will probably become cutoff and end up as a mid-latitude low before eventually filling.

    Temperatures struggling to reach 70f they say-wow they want to experience a cool wet Summer day here when we struggle to reach 60f(old money).

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    Posted
  • Location: Camborne
  • Location: Camborne

    A lot of fuss over nothing really.

    When all said and done it's just a deep upper trough something we see often around the UK.

    It will probably become cutoff and end up as a mid-latitude low before eventually filling.

    Temperatures struggling to reach 70f they say-wow they want to experience a cool wet Summer day here when we struggle to reach 60f(old money).

     

    Probably quite true but then it does come up regularly in the Model Discussion Thread.

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    Posted
  • Location: Nuneaton,Warks. 128m asl
  • Weather Preferences: Snow then clear and frosty.
  • Location: Nuneaton,Warks. 128m asl

    Probably quite true but then it does come up regularly in the Model Discussion Thread.

    Yep it does Knocker usually in the Winter half of the year when it does have more influence. 

    I don't think any of us amateurs would talk up the PV at this time of year though. 

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    Posted
  • Location: ILCHESTER
  • Location: ILCHESTER

    It will still be warm by Camborne standards in Chicago, 21-22c still looks on the cards despite the Arctic air....so it's all relative and a big t'do about nowt imo. Folk in Shetland would kill for a cold spell like that...

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    Posted
  • Location: Camborne
  • Location: Camborne

    Yep it does Knocker usually in the Winter half of the year when it does have more influence. 

    I don't think any of us amateurs would talk up the PV at this time of year though. 

     

    I beg to differ Phil I have seen it mentioned a fair bit in the last couple of months, It seems to wander around the N. Hemisphere. :)

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    Posted
  • Location: Camborne
  • Location: Camborne

    It will still be warm by Camborne standards in Chicago, 21-22c still looks on the cards despite the Arctic air....so it's all relative and a big t'do about nowt imo. Folk in Shetland would kill for a cold spell like that...

     

    I think you might be overestimating the temp.

    post-12275-0-21124000-1405156362_thumb.p

    Edited by knocker
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    Posted
  • Location: just south of Doncaster, Sth Yorks
  • Location: just south of Doncaster, Sth Yorks

    fact

    The trough originates in the Pacific NOT the polar region

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    Posted
  • Location: Napton on the Hill Warwickshire 500ft
  • Weather Preferences: Snow and heatwave
  • Location: Napton on the Hill Warwickshire 500ft

    Yes,  indeed. The anomaly chart is quite striking - winter pattern revisited.

     

    Posted Image

     

    Is that Washington at +14c ? abnormality

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    Posted
  • Location: Camborne
  • Location: Camborne

    Is that Washington at +14c ? abnormality

     

    Not totally sure what you nean stewfox. Washington State or D.C. Anyway the latest anomaly. Pretty nippy in Kansas. And is it a spoke of the Tropospheric Circumpolar Vortex?

    post-12275-0-58399400-1405197424_thumb.p

    post-12275-0-80095200-1405197431_thumb.j

    Edited by knocker
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    Posted
  • Location: Napton on the Hill Warwickshire 500ft
  • Weather Preferences: Snow and heatwave
  • Location: Napton on the Hill Warwickshire 500ft

    Not totally sure what you nean stewfox. Washington State or D.C. Anyway the latest anomaly. Pretty nippy in Kansas. And is it a spoke of the Tropospheric Circumpolar Vortex?

     

    Washington State perhaps I'm reading the chart wrong ? ie Lots positive anomalies in the north west

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    Posted
  • Location: Camborne
  • Location: Camborne

    Washington State perhaps I'm reading the chart wrong ? ie Lots positive anomalies in the north west

     

    No you are reading it correctly. Very positive anomalies in the north west.

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    Posted
  • Location: Rossland BC Canada
  • Location: Rossland BC Canada

    I find it bizarre that the NW spam filter changes the name of a prominent forecaster (controversial, whatever) so would suggest either tolerating the word in question (I am one and rather proud of it) or we all agree to write his name as Joe B'astardi.

     

    Not just a comment made in jest, visitors to this forum must scratch their heads and wonder who the hell Joe Laminate Floori might be, and in saying that, I will find out what Net-weather's minders prefer to the word h'ell. :)

     

    Ha, joke's on me, hell is fine to say around here. WTF!

    Edited by Roger J Smith
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