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#1108936 - 11/06/2012 11:05 Re: Cold fronts disappearing across the SE of Australia [Re: bd bucketingdown]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 5416
Loc: Eastern A/Hills SA
Here it is if U can't be bothered going to the link!


Edited by bd bucketingdown (11/06/2012 11:06)

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#1108945 - 11/06/2012 11:31 Re: Cold fronts disappearing across the SE of Australia [Re: bd bucketingdown]
GrizzlyBear Offline
Weatherzone Addict

Registered: 23/06/2011
Posts: 2112
Loc: Yetholme [1180m] Central Table...
BD, Thanks for posting those links to historical snow data back to the 1920's, I did see that in your documentation that is very interesting.

Crikey, thanks for pointing out that ESNO and PDO cycles are not enough to explain the dropping snow levels.

Looks like historically we are already in the longest ever stretch below 3m depth, now 20 years. Also the longest ever stretch below 2m of 12 years.

There were good reasons for predictions of heavy snow packs in 2009/10 that never eventuated and also good reasons for this winter to exceed 2m. If this year does not reach 2m then the probability that the reason is AGW is at least 99.9%.

Also this...found here
http://www.mso.anu.edu.au/~peterson/snowdepth.pdf

"The predictions for 2005 through 2009 are much higher than the actual depths. One suggested explanation was that the lower snow depths were being caused by the cloud seeding that started in 2004. However, the 2004 and 2010 actual depths are near those predicted from the historical data, and a minimum of seeding was done in the lowest year, 2006. A different explanation might be
that global warming has increased the temperature sufficiently for the precipitation to fall as rain instead of as snow. Note that in 2010, most of the snow came in a short period of very cold weather, so the agreement in 2010 could still be consistent with this explanation. In 2011 the maximum snow depth came in August, and the warm weather produced poor snow conditions and no September accumulation."

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#1109009 - 11/06/2012 18:16 Re: Cold fronts disappearing across the SE of Australia [Re: bd bucketingdown]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 1070
Loc: Dunolly..VIC .. Nth central
If we think the cold fronts are gone l guess that is not true as l am hearing that the trend is ..they have gone ( migrated)south for the winter LOL
However.. Take a look at the current MSLP dynamics!!

and thanks ROVES l will check out the SAM time series

There is currently mid latitude a CAT 3 forming in the southern ocean
I think this is the second 973 hpascal low in the past few weeks.
Its centre is located latitude 40 deg C ( which is equivalent to just south of Hobart)
Now this cat 3 has winds of 190km/hr towards its centre
The front has just been on the eastern flank and WA have just been experiencing that with 140km /hr winds on the periphery of that system
It is massive and powerful
The concern or trend as far as l have read in earlier posts
ROM said they shift south before reaching Vic and BOM has some research underway as to why
If the current trending for those exceptionally strong lows at sub polar latitudes continues into winter when the westerly belt shift north. The whole southern quadrant of VIC will be pummelled with high winds rain, snow..and we might be eating our words re cold fronts in Southeast Australia
I am encouraged by this latest sat pic
This is a monster
Check out the sat pic . That low is just barrelling in
The forecast is for that low to subside south .
But my point is if the trend for these monsters continues into winter we may cop a few doozies!!
Look forward to following that low pressure belt in the sub polar region this winter .
Just wondering if winter has some super special weather events in store

and as an aside . That ECL/subtropical low east of OZ is a CAT 1





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#1109040 - 11/06/2012 20:52 Re: Cold fronts disappearing across the SE of Australia [Re: crikey]
pete28 Offline
Weather Freak

Registered: 08/01/2007
Posts: 839
Loc: Sheffield, Canterbury, NZ
On a side note, something big might be brewing cold front wise around the 21st for SE Australia, will be a nice change from the distinct lack of cold fronts we've had over the last 2 months if it occurs...

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#1109103 - 12/06/2012 09:57 Re: Cold fronts disappearing across the SE of Australia [Re: pete28]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 5416
Loc: Eastern A/Hills SA
They are just starting crikey,(the fronts and lows of winter) look at SWWA fpor last few days and next and plenty of fronts coming our way as well too soon!
These non AGW threads are so much more interesting than the to and fro and often nonsense on the AGW threads.
These are real weather and climate in action and interesting...the others are not even worth reading much of the time lately and getting worse with continual back and forth and nothing gained at all really!

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#1109184 - 12/06/2012 18:58 Re: Cold fronts disappearing across the SE of Australia [Re: bd bucketingdown]
Coxy Offline
Weather Freak

Registered: 31/01/2011
Posts: 711
Loc: Jindalee, QLD
Originally Posted By: bd bucketingdown
They are just starting crikey,(the fronts and lows of winter) look at SWWA fpor last few days and next and plenty of fronts coming our way as well too soon!
These non AGW threads are so much more interesting than the to and fro and often nonsense on the AGW threads.
These are real weather and climate in action and interesting...the others are not even worth reading much of the time lately and getting worse with continual back and forth and nothing gained at all really!


Agreed. I just mark them read and move on. This thread has been very interesting, especially to someone like me who knows very little about this particular weather aspect.

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#1109187 - 12/06/2012 19:00 Re: Cold fronts disappearing across the SE of Australia.. [Re: bd bucketingdown]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 1070
Loc: Dunolly..VIC .. Nth central
The low pressure belt around the Antarctic looks super impressive atm
http://www.bom.gov.au/australia/charts/indian_ocean.shtml
Looking quite 'inflamed and 'puffed up' around our neck of the woods
south west WA currently having the brunt of those lows atm
with SA to come
BD
I had trouble accessing your PDF's to read ?
are the links working. Could you check
Maybe l need to upgrade my adobe reader
Jane BUNN says cold front arrives over VIC on Thursday and another l think she said Sunday


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#1109191 - 12/06/2012 19:23 Re: Cold fronts disappearing across the SE of Australia.. [Re: crikey]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 1070
Loc: Dunolly..VIC .. Nth central
The SAM ( southern annular mode has just bottomed out recently
In the first 2 weeks of JUNE 2012 the SAM index has changed from positive 1.5 to minus 2 !!
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/verf/new.aao.shtml
That's a very big change in a short amount of time ,heralding in the low pressure belt having a sudden shift toward the southern mainland
I think that sudden shifts in the SAM like this are correlated strong cold fronts and big snow dumps in the SE mountain ranges

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#1109223 - 12/06/2012 21:58 Re: Cold fronts disappearing across the SE of Australia.. [Re: crikey]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 5416
Loc: Eastern A/Hills SA
No problems getting PDF files this end Crikey, maybe U need updating Adobe. Files are large though and may take a while to load.
Gusting 100km/hr Cape naturalist SW WA now as fronts and deep low go by!

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#1109233 - 12/06/2012 23:07 Re: Cold fronts disappearing across the SE of Australia.. [Re: bd bucketingdown]
roves Offline
Weatherzone Addict

Registered: 02/02/2005
Posts: 1294
Loc: Paringa-Riverland
Heres a link for the SAM graph back to 1948 http://www.lasg.ac.cn/staff/ljp/data-NAM-SAM-NAO/SAM(AAO).htm


Edited by roves (12/06/2012 23:09)
_________________________
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#1109264 - 13/06/2012 06:43 Re: Cold fronts disappearing across the SE of Australia.. [Re: roves]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 5416
Loc: Eastern A/Hills SA
Southern WA reels from third severe storm in a week
Wednesday June 13, 2012 - 06:23 EST

Emergency services will assess damage this morning from the third severe storm to hit the southern half of Western Australia in a week.

The cold front hit the Perth metropolitan area around 9:30 pm, bringing winds of more than 100 kilometres an hour as well as heavy rain and thunder for most of the night.

The storm front also brought thunder and heavy rain causing damage and power outages at about 34,000 properties.

The Fire and Emergency Services Authority (FESA) says an SES crew was told to step down as conditions became too dangerous in the south-west.

"We've got 335 SES volunteers on board at the moment and 25 crews from South Australia arriving in Perth to assist as well," FESA spokeswoman Kathy Nastov said.

More than 160,000 homes , and some 18,000 residents were still waiting for power to be reconnected.

The damages also hit the telephone network after power was cut to service towers.


- ABC

© ABC 2012

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#1109275 - 13/06/2012 08:31 Re: Cold fronts disappearing across the SE of Australia.. [Re: crikey]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Originally Posted By: crikey
The SAM ( southern annular mode has just bottomed out recently
In the first 2 weeks of JUNE 2012 the SAM index has changed from positive 1.5 to minus 2 !!
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/verf/new.aao.shtml
That's a very big change in a short amount of time ,heralding in the low pressure belt having a sudden shift toward the southern mainland
I think that sudden shifts in the SAM like this are correlated strong cold fronts and big snow dumps in the SE mountain ranges


Latest reading aproaching -3! not been taling notice of this for very long but that is a BIG drop off!

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#1109278 - 13/06/2012 08:50 Re: Cold fronts disappearing across the SE of Australia.. [Re: roves]
GrizzlyBear Offline
Weatherzone Addict

Registered: 23/06/2011
Posts: 2112
Loc: Yetholme [1180m] Central Table...
Originally Posted By: roves
Heres a link for the SAM graph back to 1948 http://wdoww.lasg.ac.cn/staff/ljp/data-NAM-SAM-NAO/SAM(AAO).htm


I am looking at that graph since 1948 with some shock. You can see that famous first bad year 1973, but look at the 7 year smoothed trend, seems to going just one way up, just like age and the warming and decreasing cold fronts.

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#1109280 - 13/06/2012 08:58 Re: Cold fronts disappearing across the SE of Australia.. [Re: GrizzlyBear]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 5416
Loc: Eastern A/Hills SA
This is the only reliable AAO data Peter

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#1109287 - 13/06/2012 09:55 Re: Cold fronts disappearing across the SE of Australia.. [Re: bd bucketingdown]
GrizzlyBear Offline
Weatherzone Addict

Registered: 23/06/2011
Posts: 2112
Loc: Yetholme [1180m] Central Table...
The data is all good BD, the monthly data listed at the bottom of the link is all the same, you can graph it in Excel and you will see its the same as in the data you posted which has a link here...
http://www.cpc.ncep.noaa.gov/products/precip/CWlink/daily_ao_index/aao/month_aao_index.shtml
Now try smoothing the SAM data over 1 years and then 7 years in Excel and you will indeed get a one way trend up.

This is hard evidence to back up what we are noticing on the ground. I was not expecting the trend to be so obvious in SAM. This is exactly what we are witnessing on the ground cold fronts getting weaker decade by decade in fact for the last 60 years. That is quite scary to me.

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#1109313 - 13/06/2012 13:32 Re: Cold fronts disappearing across the SE of Australia.. [Re: GrizzlyBear]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 5416
Loc: Eastern A/Hills SA
i was reffering to the pre-1979 data Peter which is estimated.
The AAO is responding to Solar/Ozone conected pressure change effects in the main, as that is falling away I expect the AAO to do the same slowly with time.


Edited by bd bucketingdown (13/06/2012 13:33)

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#1109426 - 13/06/2012 22:06 Re: Cold fronts disappearing across the SE of Australia.. [Re: bd bucketingdown]
crikey Offline
Weatherzone Addict

Registered: 01/02/2011
Posts: 1070
Loc: Dunolly..VIC .. Nth central
great page on the SAM ROVES ,, Thanks
I think SAM is in record negative territory today
Hasn't been this low since??
1950's.. Is that correct?
and is this a record
SAM dropping from pos 1.5 to minus 2.8 in just 2 short weeks? Haven't been able to find SAM anomaly records ??
current SAM looks very large cold frontish atm


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#1109431 - 13/06/2012 22:24 Re: Cold fronts disappearing across the SE of Australia.. [Re: crikey]
S .O. Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1266
Loc: Southern Victoria
Crikey ,

One off spikes are not sustained 3 mth running means , as what is shown in the long term Graph above posted by BD ?

Regardless its good to see a rapid down ward stroke though , which will no doubt spell SNOW in the next 14 days >...!!!! We hope . And possibly even shorter for NZ .
_________________________
" I walk around in the Summertime , saying ' how about this Heat ' !
I'm an ............ , a real ........ ............. "

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#1109496 - 14/06/2012 06:57 Re: Cold fronts disappearing across the SE of Australia.. [Re: S .O.]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1133
Since it got too -4 last Year Crickey in early August when it snowed neally all of New Zealand

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#1109560 - 14/06/2012 18:11 Re: Cold fronts disappearing across the SE of Australia.. [Re: _Johnno_]
GrizzlyBear Offline
Weatherzone Addict

Registered: 23/06/2011
Posts: 2112
Loc: Yetholme [1180m] Central Table...
wrong thread, will post a little latter


Edited by PeterDuke (14/06/2012 18:12)

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