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#1263166 - 10/05/2014 20:16 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
No worries Petros. some more info may help
Before the SSW event the uppers were cold( normal)(minus 70deg c) No capping ..

Suggesting the warm uplift is caused by a strong sub polar low that has no warm anomaly at the upper layer to cap it( inversion)
The warmer air (minus 38 deg c)pushes through the minus 70 deg c layer and spills over and down somewhat like a volcano. Displacing the colder air downward and outward

Mid latitude storms l believe can be capped from a warm upper air. So this is different

Just looking at some of those temps at the lower stratosphere layer 200hPa here curently

-------------------------
DIAGRAM below is lower stratosphere 200hpa below the 10hPaupper stratosphere

A warm anomaly in the SSW event at the 200hpa layer currently is minus -38 deg c

The cold anomaly tongues there on this map is minus 75 deg! c .Come DOWN from colder 10Hpa layer ( downwelling)


source
http://www.bom.gov.au/australia/charts/v...it=Refresh+View
-----------------------------------
Here is the temperatures for the 10hPa upper stratosphere layer
in the SH for 2014/2014

Notice the mean in December(summer in the SH) is minus 25 deg c
and
the mean 10hPa temp in the SH in July is minus 75 deg C

So the stratosphere naturally gets colder in winter

These SSW events are bubbles of warmer anomalies

So a bubble of air at minus 38 deg c in May is a significantly warm anomaly compared to the surrounding air

Here is the 10hPa upper stratosphere mean temps and the anomalies from 2013 into 2014

Nothing unusual here for may 2014 ..yet


source
http://www.cpc.ncep.noaa.gov/products/stratosphere/temperature/10mb6590.gif

In fact you can se that last years 2013 SSW bubble did not affect the overall mean 10 hPa Antarctic anomaly at all
It was an isolated event.
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#1263632 - 15/05/2014 07:23 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
My earlier post:
"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"

The result of SSW near Australia is this.......
"South Australia feeling the heat the most
Brett Dutschke, Wednesday May 14, 2014 - 14:50 EST

It may seem strange mentioning "heat" only a few weeks away from winter, but it is all relative - a late-autumn heatwave is developing and it is South Australia which will be feeling it the most, warming five-to-ten degrees above average.

This week has started in a warm way, at least in terms of day-time temperatures, warming a few degrees above average and it is only going to get warmer.

Maximum temperatures for the next seven-to-ten days will average five-to-seven degrees above the long-term norm across the state. Some centres will be as much as 10 degrees above average on some days.

If these anomalies occurred in summer it would mean temperatures reaching the mid-to-high 30s but at this time of year it means a relatively comfortable mid-to-high 20s.

A run of days in the mid-to-high 20s is very unusual for this time of year, it is more typical of April.

For some centres it will be the warmest week this late in the season since the 1950s. Adelaide will average a maximum of about 24 degrees and Ceduna about 27 degrees, making it the warmest week this late in the season since 1957, when heading into winter they averaged 24.5 and 27.3 degrees respectively.

Kyancutta is one of the best placed towns to beat the 1957 heat by averaging a maximum of more than 27 degrees, making it the warmest late-season week since 1934 when it averaged 28 in late May.

With days warming up this much, nights will also warm up, enough to keep frost away and significantly reduce the need for using heaters.

It is not all comforting news - the run of warmer-than-average days is largely due to clearer-than-normal skies and a lack of cold fronts which means we are also looking at an extended dry run. The warm, dry spell will lead to higher-than-normal evaporation, counteracting the recent rainfall and drying out dams and starving crops and gardens.

Evaporation will amount to as much as four-or-five millimetres per day in some areas, about twice the normal evaporation rate for this time of year, more typical of April, just like this week's temperatures.

The polar jetstream is now dipping south of mainland Australia after having just been a long way north and is leading to a "blocking" high over the Tasman Sea. As a result, cold fronts are now being forced south of mainland Australia, leaving skies fairly clear and winds northerly most of the time. Northerlies are taking advantage of the sunshine to warm each day a few degrees above average.

It won't be until at least late next week before the jetstream shifts far enough north to allow fronts to penetrate further, so significantly cooler and wetter weather is a fair way off.

- Weatherzone

© Weatherzone 2014


Edited by bd bucketingdown (15/05/2014 07:27)

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#1263634 - 15/05/2014 07:37 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 SSW has now moved east or ENE and is slowly weakening and has transferred the next upstream ridge near South America to a new SSW area...interesting...likely responsible for the easterly wind strengthening near north S American coasts ocean area maybe(as the SSW works its way downwards as per explanation post last page).


Edited by bd bucketingdown (15/05/2014 07:40)

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#1263648 - 15/05/2014 09:54 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
I'd imagine that we wont see anymore temp anomalies until there are further flux bursts into the stratosphere.

As these things go it's been fairly minor so far - but my understanding is it may help to make the stratosphere more vunerable to future penetration.

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#1263671 - 15/05/2014 13:10 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
It has not been so minor here in SA and in other eastern states Snowbaby, as we have really dried out with the SSW giving high domination and drier and warmer weather and looks like continuing for a week or two yet till things settle down...does not help crops and pasture and gardens, though good living weather!
And quoting from Blair Trewin and the SA thread
"If today's ECMWF run is correct and the warm spell remains unbroken until (at least) the end of next week, it will set records for long runs of warm days in May* in Adelaide, Melbourne and Sydney (and probably plenty of other places too, though I haven't checked).

(* - for these purposes I'm including the late May/early June 1957 event, which in some cases, e.g. Adelaide days over 22, surpasses anything contained entirely within May)."


Edited by bd bucketingdown (15/05/2014 13:11)

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#1263757 - 15/05/2014 22:59 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
mmmm...maybe high squatting on se corner will set up pump for some renewed heat flux..

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#1263782 - 16/05/2014 07:43 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Warm autumn day in Hobart sets 100-year record
Thursday May 15, 2014 - 20:29 EST

Hobart has experienced its warmest late autumn day in more than a century.

The state's capital reached 23.9 degrees in the afternoon, making it the warmest day at this time of year since records began in 1896.

Ian Barnes Keoghan of the Bureau of Meteorology says the whole country is experiencing a heatwave.

"We're certainly seeing a lot of very mild weather, that sort of whole south-east part of the country's going through a period of extended very mild weather, which looks like continuing for some little time," he said.

This week is also expected to be the warmest week for this time of year since 1934.

ABC

© ABC 2014

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#1263825 - 16/05/2014 13:57 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1694
Is the SSWs warming reflected here on the NOAA temperature anomalies shown for the past 7 days for us and well south of Australia? I'm guessing the two are linked?

http://www.esrl.noaa.gov/psd/map/images/rnl/sfctmpmer_07b.rnl.html


Edited by _Johnno_ (16/05/2014 13:57)
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#1263875 - 16/05/2014 20:37 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Yes, I would say so Johnno
cheers

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#1263879 - 16/05/2014 20:47 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
Here is a snap of that warm Antarctic temp' anomaly Johnno



The surface anomlaies warm at the Antartic pole with colder anomaly at upper stratosphere 10hpa




I think this means strong descending air compresses air under for high pressure and warming at the surface
The air pushed down is then forced out radially around the Antartic and a belt of low pressure convection emerges

The pattern is very zonal curently
Not what you would see from a SSW atmospheric wave activity. Maybe a bit early.

Last year the SAM went strongly positive first as the wave action started

SAM/AAO curently close to neutral 16th May 2014
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/verf/new.aao.shtml

The westerly belt is certainly well contracted south currently with a stalling high in the Tasman

WE still have nice looking North west cloud band arriving


Just have to sit back and see how it all 'pans out'
Thanks for the obs' and keeping the thread alive


Edited by crikey (16/05/2014 20:48)
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#1263885 - 16/05/2014 21:59 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
The SSW & warming effects are now weakening and things are likely to slowly return to normal temp wise after a while.


Edited by bd bucketingdown (16/05/2014 22:00)

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#1263919 - 17/05/2014 10:57 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
Record late Autumn warmth for Sydney
Drew Casper-Richardson, Saturday May 17, 2014 - 10:31 EST

Sydney is enjoying late Autumn warmth not experienced since temperature records began all the way back in 1859.

The working week ended in spectacular fashion with the city reaching 25 degrees under clear blue skies. Friday was the seventh day in a row where the mercury exceeded 22 degrees, the longest stretch this late in May since records began over 150 years ago. The previous record was six days which occurred in 1974.

The longest run of days exceeding 22 degrees at any time during May is nine which occurred in 1978 and again in 2007. The current forecast is for Sydney to reach 24 or higher for at least the next seven days which will eclipse the current record.

A lack of strong cold fronts has allowed the summer heat to linger over the interior. A near-stationary high pressure system over the Tasman Sea has allowed northerly component winds to filter this heat into the Sydney Basin. The high has also brought mostly sunny skies giving the sun ample time to warm the city.

The warmth isn't over yet though. Since 1859, Sydney has only had 21 days in May where it has reached 25 degrees, making it a one in every seven year event. Including Saturday, five of the next seven days are forecast to reach 25, highlighting just how unseasonably warm it is.

Sydney's average May maximum is 19.4 degrees. The average for this May so far is nearly three degrees higher at 22.1. The highest May average on record is 22.7 in 1958 and with the current forecast this could be broken this year.

- Weatherzone

© Weatherzone 2014

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#1263946 - 17/05/2014 17:47 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
Some prognosis reminiscent of the polar vortex being stretched.







There’s been a concentration(380+ du) of ozone south of us for some time which seems to pretty much match the area of the recent stratospheric temp anomaly. There are some studies suggesting an increase ozone in our patch, could be a result of fires(seasonal) in Indonesia etc.






Edited by snowbaby (17/05/2014 17:52)

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#1264369 - 22/05/2014 19:04 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
Yes. the SSW warming bubble has subsided considerably
Of note currently is the very strong sub tropical Jetstream
BUT
A VERY WEAK sub polar jet . Almost non existent currently( marked with a purple line on the diagram posted)
This sub polar jet is crucial for our cold fronts . It is looking VERY benign currently



source
http://www.bom.gov.au/australia/charts/v...it=Refresh+View
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#1264398 - 22/05/2014 23:02 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
Currently looks like a little flux activity is starting to get into the stratosphere again(19th&20th long arrows think it's wave 1) - hard to compare it to earlier recent bouts as Esrl's EPflux plotter is either not functioning properly some of the time - or when it does is only giving me reading up to 16May.




Edited by snowbaby (22/05/2014 23:11)

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#1264467 - 23/05/2014 17:12 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 2586
Loc: Tweed Heads
Ah yes 'snowbaby' I see a new SSW bubble is emerging east at 180 longitude / date line in the sub polar region of course
as seen from the CDAS animation a few posts back
A single blob of SSW curently around the SH sub polar belt
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#1264473 - 23/05/2014 17:53 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
...it's pretty quiet on the western front cold outbreak wise - it's all I can find to do of much interest at the mo...hoping that these little flux forays eventually weaken the vortex enough for an exciting late winter/spring..


Edited by snowbaby (23/05/2014 17:55)

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#1264529 - 24/05/2014 22:11 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
snowbaby Offline
Weather Freak

Registered: 05/08/2009
Posts: 295
Loc: Albany, W.A
Wow quite a spike in wave activity appearing @ 100hPa., 22nd May. Seems to be wave 2 though hard to tell if wave 1 is involved until tomorrow’s outputs perhaps. Extreme right of graph at bottom - sorry I dont have Crikey’s marker pen.



Almost certainly the biggest burst of the year so far - keen to find out whether it’s significantly anomalous or not.

Must be synopticaly induced. Any ideas?


Edited by snowbaby (24/05/2014 22:13)

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#1264544 - 25/05/2014 08:24 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6033
Loc: Eastern A/Hills SA
It does that every year peaking generally in mid winter-early spring in southern hemisphere SB (the waves they measure I mean)


Edited by bd bucketingdown (25/05/2014 08:25)

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#1264784 - 27/05/2014 10:30 Re: Stratospheric sudden warmings (SSWs) [Re: crikey]
CoastalStorm22 Offline
Weatherzone Addict

Registered: 10/07/2006
Posts: 2701
Loc: Lane Cove, Sydney, NSW
Originally Posted By: crikey
Ah yes 'snowbaby' I see a new SSW bubble is emerging east at 180 longitude / date line in the sub polar region of course
as seen from the CDAS animation a few posts back
A single blob of SSW curently around the SH sub polar belt


That bubble appears to have stalled and is gaining strength, with a weak cooler bubble moving in south of Aus now right in time for our cool down after this record heat.

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