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#1223382 - 02/12/2013 20:57 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
N Hemp 2012

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#1223383 - 02/12/2013 20:59 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
S Hemp 2010 not a bad one there in 2010 followed by a cold burst!



Edited by bd bucketingdown (02/12/2013 21:00)

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#1223385 - 02/12/2013 21:05 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Many years in S Hemp it is just a bit of a mess really!


and this year...

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#1223387 - 02/12/2013 21:08 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
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Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
These are for the whole hemispheres 60-90N N Hemp and 60-90S S Hemp, so won't show the area near Australia, England or wherever...just the whole hemispheres


Edited by bd bucketingdown (02/12/2013 21:08)

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#1224549 - 10/12/2013 20:52 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
There is an intense surface low forecast to ramp up in the sub polar nth Pacific next week around 16th dec2013
If these things get big enough ( the wind speed gets a purple coloring 80-100knots) these lows can initiate a significant SSW

Could be an interesting watch
Probably still a little early as not in the depths of winter yet


source link
http://www.bom.gov.au/australia/charts/v...it=Refresh+View

Note the cyclone in central Indian ocean next week curently developing now near equator on southern H side
------------------

THanks BD for those stratosphere profiles smile



Edited by crikey (10/12/2013 21:00)
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#1224613 - 11/12/2013 13:24 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
CoastalStorm22 Offline
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Registered: 10/07/2006
Posts: 2701
Loc: Lane Cove, Sydney, NSW
Very interesting Crikey.

The boys over at Weather Bell have also been hinting at the possibility of SSW in the coming weeks.

Something to keep an eye on anyway.

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#1224618 - 11/12/2013 14:08 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
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Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Last years SSW in N hemp was preceded by a cold surge of sorts same as is evident now


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#1240595 - 09/02/2014 11:36 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
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Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
I posted your page on WUWT Crikey as it looked so similar to the NH event shown on their thread Cheers Ian(BD)
http://wattsupwiththat.com/2014/02/08/wh...ex/#more-102862
http://weathercycles.wordpress.com/2013/...-1/#comment-309


Edited by bd bucketingdown (09/02/2014 11:37)

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#1263033 - 08/05/2014 21:30 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
CoastalStorm22 Offline
Weatherzone Addict

Registered: 10/07/2006
Posts: 2701
Loc: Lane Cove, Sydney, NSW
Is that southern hemisphere SSW developing south of Aus??



source
http://www.cpc.ncep.noaa.gov/products/intraseasonal/temp10anim.shtml

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#1263041 - 09/05/2014 07:25 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Good spotting CS, needs to be watched!
cheers

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#1263042 - 09/05/2014 07:53 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
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Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Interestingly(see previous page for CS post re-SWW Loop, and past few posts also)
on that loop hot spot in NH which shows first on the loop corresponds to this warm temp anomaly shown in central-east Russia-North China area

and
also interestingly, my own models have been forecasting a warmer drier spell for SE australia for several weeks now, lasting for 2 to 3 weeks starting from next week onwards
cheers


Edited by bd bucketingdown (09/05/2014 08:03)

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#1263096 - 09/05/2014 16:34 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
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Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
Nice obs' CS22.!! Yes that is a nice area of SSW developing in the SAME place/longitude as last year. You would expect some nice wave activity to evolve from this disturbance
You can see the colder anomaly on the eastern side
This because this is a wave disturbance. Hot and cold anomalies adjacent
Taken a snap of that
This should get the Jetstream wavy/ meridonal as time goes on and a decent dip into -neg for the SAM

5th May 2014



and the question is . What has started this warm anomaly
Some researchers suggest strong lows underneath in the stratosphere. Some say ozone changes in the stratosphere
Could be other things

Hope to go looking
Here is the ozone anomaly time series

http://www.cpc.ncep.noaa.gov/products/CDB/Extratropics/figs5.gif
for a start. Haven't really looked in detail here so no idea really. At this stage
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#1263098 - 09/05/2014 17:06 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
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Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
Current SH MSLP showing some very strong low pressure belt at 60s currently
You can see a pair of strong sub polar cyclones siting under he warm stratospheric anomaly, raising air into the stratosphere via a convective vortex perhaps



Quite amazing how the stratospheric temps change dramatically at this time of the year.( swing bi-polar see saw April/early May)
Its our turn now.. Bring on winter wonderland. says me hopefully

The fronts were not particularly good last year
But last weeks awesome cold front could be a good start for 2014.
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#1263103 - 09/05/2014 19:29 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
Petros Offline
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Registered: 30/12/2002
Posts: 6598
Loc: Maffra, Central Gippsland, Vi...
Crikey, wouldn't a warm anomaly SW of Vic create a period of "less intensive" fronts while that anomaly is present?

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#1263129 - 10/05/2014 09:07 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
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Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
"SSW's alter the tropospheric circulation through a process called potential vorticity thinking (pretty odd, I know). PVT essentially acts like a thermal wind adjustment. During an SSW, changes to the stratospheric polar vortex in the lower stratosphere cause an imbalance. Generally speaking, when a flow is out of balance, the adjustment process ripples to regions relatively far from the location where the imbalance occurs. In this case, when there is an imbalance in the lower stratosphere, the adjustment extends all the way down to the earth's surface. Indeed, the adjustment "excites" the negative phase of the Northern Annular Mode (also known as the Arctic Oscillation) and the negative phase of the North Atlantic Oscillation. In turn, this "excitation" can pave the way for an outbreak of cold air over the Northeast States"http://www.wunderground.com/blog/24hourprof/sudden-stratospheric-warmings-ssws

Note bold, SSW's work way down to surface often, not the other way around, so the effects of the SSW are likely still to be felt, in this case as high pressure not low pressure I would expect anyway by instinct!

Also below from same source...
SSW's were discovered over Berlin in the early 1950s (the good old days). Subsequent research indicated that upward-propagating, planetary-scale Rossby waves transported energy and momentum into the stratosphere. Without getting into too much atmospheric physics, upward-propagating Rossby waves produce a meridional transverse circulation in the stratosphere, with sinking air over high latitudes and rising air closer to the equator. The dramatic compressional warming associated with the subsidence over high latitudes is the hallmark of SSW's that I mentioned earlier. As you can imagine, dramatic warming in the region of the polar vortex upsets the circulation in the stratosphere. As the normal north-south temperature gradient breaks down, winds associated with the polar-night jet weaken (thermal wind arguments) and sometimes reverse (become easterly). If stratospheric winds at this level become easterly, further upward transfer of wave energy is blocked, and the deceleration of westerly winds and subsidence warming work it way downward.


Edited by bd bucketingdown (10/05/2014 09:11)

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#1263149 - 10/05/2014 16:24 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
Fascinating phenomenon. I'm a little cautious though-until I know more-about the stratospheric warming we are currently seeing as noted.

The cdas 10hPa area of temp anomaly posted by Crikey above after mid to late April(also reflected with 30 and 50 hPa anoms animations from same site),when it seems to intensify most, seems to have drifted marginally to the north. That may be why it does not appear in the graphic linked below (apologies having trouble getting the image to post at moment)- that is, there is no sign of the warming still being in the stratospheric polar vortex at present, even though there is anomolous warming in the stratosphere in an area bordering the vortex.

Even were the anomaly in the vortex, I'm not sure that it is significant enough to make it a factor in driving anomalies within the troposphere just yet.

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/hgt.aao.shtml

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#1263152 - 10/05/2014 17:16 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
The warm anomaly is averaged out on that hemispherical chart by the cold anomaly to the east. and much of it is north of 60S also and is not shown on that chart Snowbaby.
It is quite significant and will affect the weather lower down and already is doing so on the progs with highs starting to dominate in the Australian region, and that feature is likely to continue to have affects for a couple to come yet at least I would suggest.
As I said earlier my models have forecast a drier, maybe warmer spell for SE Australia for many weeks now for this 2 to 3 week period ahead. So it fits in well imo anyway. We shall see how it develops...interesting!

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#1263157 - 10/05/2014 18:37 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
Petros. Here is a visual animation 3D of how a massive uplift in air from a sub polar vortex(low) might punch through into the upper stratosphere (10mb)and how descending air might behave
Keep in mind this is a drum animation not a real life atmospheric video

source
http://www.upscale.utoronto.ca/PVB/Harrison/Vibrations/

The air punching through is warmer than the air at 10mb
note the upward phase of this standing wave action

You can see from the animation this disturbance also causes a downwelling of colder stratospheric air toward the surface ( troposphere)
The result of the volcanic' style explosion is riplesand waves in the atmosphere at all layers and longitudes as the wave action propagates
There are dips and troughs.
As to how this current SSW will affect Gippsland. This will be a good weather watch to take notes. LAST YEAR we had the same. What happened?

Snowbaby
Last year there was some effects from the wave action as the SAM went strongly negative about 2 weeks from the initiation of the SSW and subsequent wave activity around the sub polar region
Pages 1-3 of this thread cover last years event

Here is a snap of the first SSW last year .
29th May 2013


Note that this current SSW in the SAME location is 3 weeks e earlier!!!at 5th May 2014


Here is the effect on the AAO/SAM last year. You can see the SSW commenced around the 29th May and you can see the amplitude of the SAM commenced increasing about a week later
With the dips and troughs in SAM getting stronger in successive peaks and troughs 'Look at one of the larger dips in July to August!!
SSW sending the SAM into a higher energy wave pattern with increasing amplitude.
You would expect this to happen again.?









Edited by crikey (10/05/2014 18:40)
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#1263159 - 10/05/2014 18:57 Re: Stratospheric sudden warmings (SSWs) [Re: bd bucketingdown]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 6598
Loc: Maffra, Central Gippsland, Vi...
Originally Posted By: bd bucketingdown
"SSW's alter the tropospheric circulation through a process called potential vorticity thinking (pretty odd, I know). PVT essentially acts like a thermal wind adjustment. During an SSW, changes to the stratospheric polar vortex in the lower stratosphere cause an imbalance. Generally speaking, when a flow is out of balance, the adjustment process ripples to regions relatively far from the location where the imbalance occurs. In this case, when there is an imbalance in the lower stratosphere, the adjustment extends all the way down to the earth's surface. Indeed, the adjustment "excites" the negative phase of the Northern Annular Mode (also known as the Arctic Oscillation) and the negative phase of the North Atlantic Oscillation. In turn, this "excitation" can pave the way for an outbreak of cold air over the Northeast States"http://www.wunderground.com/blog/24hourprof/sudden-stratospheric-warmings-ssws

Note bold, SSW's work way down to surface often, not the other way around, so the effects of the SSW are likely still to be felt, in this case as high pressure not low pressure I would expect anyway by instinct!

Also below from same source...
SSW's were discovered over Berlin in the early 1950s (the good old days). Subsequent research indicated that upward-propagating, planetary-scale Rossby waves transported energy and momentum into the stratosphere. Without getting into too much atmospheric physics, upward-propagating Rossby waves produce a meridional transverse circulation in the stratosphere, with sinking air over high latitudes and rising air closer to the equator. The dramatic compressional warming associated with the subsidence over high latitudes is the hallmark of SSW's that I mentioned earlier. As you can imagine, dramatic warming in the region of the polar vortex upsets the circulation in the stratosphere. As the normal north-south temperature gradient breaks down, winds associated with the polar-night jet weaken (thermal wind arguments) and sometimes reverse (become easterly). If stratospheric winds at this level become easterly, further upward transfer of wave energy is blocked, and the deceleration of westerly winds and subsidence warming work it way downward.


Thanks, but must admit I didn't understand hardly a word of it. All the quotes relate to the Southern hemisphere?

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#1263160 - 10/05/2014 19:05 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
Petros Offline
Meteorological Motor Mouth

Registered: 30/12/2002
Posts: 6598
Loc: Maffra, Central Gippsland, Vi...
Registered: 01/02/2011
Posts: 1629
Loc: Tweed Heads
Re....
Petros. Here is a visual animation 3D of how a massive uplift in air from a sub polar vortex(low) might punch through into the upper stratosphere (10mb)and how descending air might behave
Keep in mind this is a drum animation not a real life atmospheric video

source
http://www.upscale.utoronto.ca/PVB/Harrison/Vibrations/

The air punching through is warmer than the air at 10mb
note the upward phase of this standing wave action

I still don't get it, sorry to all posters above trying to help... If the uppers are warm, doesn't that make it harder for "massive uplift in air from a sub polar vortex(low) might punch through into the upper stratosphere (10mb)"???

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