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The latest runs from both GFS and ECMWF shows a very nice and quick tropospheric respons to the SSW with rising geopotential heights in Barents and Norwegian sea and negative zonal wind anomalies propagating dowards from the stratosphere.

.U60N.thumb.png.72ecf6f1079ec6ad6dfa5989494f4d09.png   

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It's fantastic to finally see these kind of charts at t48, t72, t96, t120 and not t384 and never moving any nearer.

gfsnh-10-48.thumb.png.7650f05acd4eb42a6d21a4e50aac216f.pnggfsnh-10-72.thumb.png.afe25cca6a7224dd545ccac79a95db1d.png

gfsnh-10-96.thumb.png.906b3ed61dc7c91ec4a0ce88e42899e0.pnggfsnh-10-120.thumb.png.ef51eeefd7f2f6c95e1f2c6a4fd2ca4f.png

 

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1 hour ago, Summer Sun said:

 

I know everyone is probly busy at work etc , but isn't this tweet very impressive and going to have major impacts on the weather as in HLB . I mean as in record setting terms ?? 

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PV starting to come under pressure here - starting to take on the dumbbell look as the mother vortex gets split.

09.02.18 1200z.svg

Edited by JeffC

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1 hour ago, JeffC said:

PV starting to come under pressure here - starting to take on the dumbbell look as the mother vortex gets split.

09.02.18 1200z.svg

apologies, that link doesn't want to work...

https://earth.nullschool.net/#current/wind/isobaric/10hPa/overlay=temp/orthographic=-2.02,95.03,327

should be OK!

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Couple of quick GIFS from the Berlin site, nothing particularly exciting re: up and coming commentary, more of contributing to the thread from a historical perspective and charting developments now as we see them ahead of SSW proper, to review later, further in future. Esp. as the previous threads are such a valuable source of info.

30hPa blooming and D10 offers some intrigue for just what can the weakened, fractured parent lobe take by way of secondary pulse of warming.

The PV Plot shows the disturbance well and it's ripe for a fishing analogy, the Siberian vortex tad pole like and spun a lifeline from the Canadian daughter vortice, then reeled in to regroup. Only then to be subject to the aforementioned warming pulse.

Fascinating stuff.!

ezgif-1-90957407ab.gif

ezgif-1-7bf4274402.gif

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Can somebody please provide the complete list of Feb SSW's?

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41 minutes ago, summer blizzard said:

Can somebody please provide the complete list of Feb SSW's?

This might be useful - a complete list of SSW's from 1958 to 2014 from a paper titled: A sudden stratospheric warming compendium by Dr Amy Butler et al, published in Feb 2017. The list is in Section 2.2.  https://www.earth-syst-sci-data.net/9/63/2017/essd-9-63-2017.pdf

5a7e0c0d3c458_SSWEventsListAmyButlerCompendiumPaper.thumb.jpg.cc40cb4be10dfffad74fe9f09788913e.jpg

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Even to my untrained eye the 0z seems to be offering a SSW eventfest. Some pretty significant warming going on as it seems intent on destroying a strong polar vortex over over Canada. 

 

 

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Can anyone post the zonal gefs from the 00z run which is not latitude specific (or if it is, can they show 65N and 75N)? 

60N on the weather is cool website doesn’t show any negative flow at 500hpa. Just wondering how far south it gets. 

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15 hours ago, Blessed Weather said:

This might be useful - a complete list of SSW's from 1958 to 2014 from a paper titled: A sudden stratospheric warming compendium by Dr Amy Butler et al, published in Feb 2017. The list is in Section 2.2.  https://www.earth-syst-sci-data.net/9/63/2017/essd-9-63-2017.pdf

5a7e0c0d3c458_SSWEventsListAmyButlerCompendiumPaper.thumb.jpg.cc40cb4be10dfffad74fe9f09788913e.jpg

Thanks..

I wanted to look at the effects on March primarily (though it's notable that a lot of Feb SSW years were not that notable, a lot of Jan ones look better) and when we filter out those part of an El Nino event we get..

2008

2001

1999

1989

1984

1979

When compared to the 1981-2010 average for March and viewing 1C from average as Average) then those years had a relatively cool bias with 50% of those years near average and 50% below. The range though was actually 7.5C to 4.7C with only two of the six years actually above (hence a weighted mean would probably suggest a CET somewhere in the 5.5-5.9C range. 

 mar.thumb.png.47e70310c0f5a7a1a48371cbcaf07313.png

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I'm but a devoted learner in atmos. sci. and this modeled 10hpa distribution of winds and temps seems quite unusual (especially in the strat), and unbalanced/unstable.

By definition the SPV is a windfield encompassing the very cold temp values, which is certainly not portrayed here. Those are actual temps, not anomalies.
The lower levels show a similar distribution, but not as extreme.

Yes, I'm aware of all the public postings by strat scholars on wxtwitter describing the warming and split and "wellings" and "fluxes" attendant thereto.

I also note that there should be a destructive measure of sunlight south of 70N by now.

If this warming isn't "final" I sure don't see another down the road after this, even if there is some recovery of the westerlies as anticipated.

Thanks to each of you for your contributions. I've learned things /s.

Capture.PNG

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5 hours ago, summer blizzard said:

I wanted to look at the effects on March primarily (though it's notable that a lot of Feb SSW years were not that notable, a lot of Jan ones look better) and when we filter out those part of an El Nino event we get..

2008

All those events are in the Meteociel ERA archive. I see nothing that remotely resembles what is about to take place with the cross polar warming and splitting. There are displacements with the warming coming from the Asian sector and in some instances the warming is well before the reversal date. One advantage of the ERA set is that you can see what happened through the atmosphere .... even down to ppn charts that show snow!

http://www.meteociel.fr/modeles/archives/archives.php?day=1&month=2&hour=0&year=1979&map=4&region=nh&mode=2&type=era

PS. it's highly unlikely the cold would be conveniently encapsulated in a calendar month ...have you looked at different permutations of days?

Edited by Gael_Force

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