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#1105049 - 21/05/2012 11:57 Re: ENSO Discussion 2012. [Re: CoastalStorm22]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1745
May JAMSTEC has just updated and seems to have locked in a Negative IOD for Winter and Spring if anything it has strengthened it. ENSO looks Neutral for the rest of the Year which I personally think is the most likely outcome, for some reason can't see an El Nino forming.


Edited by _Johnno_ (21/05/2012 11:58)
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#1105050 - 21/05/2012 12:11 Re: ENSO Discussion 2012. [Re: _Johnno_]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6050
Loc: Eastern A/Hills SA
Well I'll give you a reason Johnno....
see huge mass of cold water just under surface over eastern half of Pacific ocean at 5S to 8S on depth analysis TAO
http://www.pmel.noaa.gov/tao/jsdisplay/
Plus my Indices have never strayed from neutral to even very very slight La Ninaish in the odd week of prediction for rest of 2012.
cheers

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#1105052 - 21/05/2012 12:15 Re: ENSO Discussion 2012. [Re: bd bucketingdown]
Long Road Home Offline
Meteorological Motor Mouth

Registered: 08/10/2007
Posts: 8802
Loc: Northern Beaches Syd
JAMSTEC (which nailed last years cold summer predictions at this time last year) is going for a colder spring over pretty much the entire country. Summer (looks like we might actually see it this time) predicted to be a little warmer than average across the eastern half, but only by around 0.1-0.3C.. slightly higher for eastern inland), it's also predicting drier conditions in these warmer areas. Nothing spectacular, fairly average.

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#1105066 - 21/05/2012 13:24 Re: ENSO Discussion 2012. [Re: Long Road Home]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1745
Thanks Ian. Yep I remember we both went for Negative values for ENSO for Dec 1st Ian couple of months back! So be interesting to see if it still heads that way
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#1105106 - 21/05/2012 16:05 Re: ENSO Discussion 2012. [Re: bd bucketingdown]
CoastalStorm22 Offline
Weatherzone Addict

Registered: 10/07/2006
Posts: 2984
Loc: Lane Cove, Sydney, NSW
Originally Posted By: bd bucketingdown
Well I'll give you a reason Johnno....
see huge mass of cold water just under surface over eastern half of Pacific ocean at 5S to 8S on depth analysis TAO
http://www.pmel.noaa.gov/tao/jsdisplay/
Plus my Indices have never strayed from neutral to even very very slight La Ninaish in the odd week of prediction for rest of 2012.
cheers


Where on the TAO site do i find this mass of cold water?
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#1105117 - 21/05/2012 16:44 Re: ENSO Discussion 2012. [Re: CoastalStorm22]
Arnost Offline
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Registered: 10/02/2007
Posts: 3909
Go to the buoy summary plot and manually create a plot by chosing bouys/parameters. Its not easy but doable.

In the meantime, here's BOMs 150m basin wide temps / anomalies. There is colder water both sides of the equator - which is just a sliver af warmer water in the midst.



Edited by Arnost (21/05/2012 16:45)
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#1105130 - 21/05/2012 17:46 Re: ENSO Discussion 2012. [Re: Arnost]
ColdFront Offline
Meteorological Motor Mouth

Registered: 29/06/2008
Posts: 19046
Loc: The Beach.
Yeah I am starting to think my +0.8 forecast is optimistic. Winds are characteristic of nina which is ironic given they failed for the most part throughout summer at the height of the official nina. A deep easterly flow onto the Queensland coast in May is not exactly indicative of a trend towards nino that is for sure and we are approaching the end of the predictability barrier.

There would need to be a decent shift in atmospheric conditions across the Arafura Sea ( a solid WWB ) in the short term to get that warm subsurface water moving east again.
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#1105211 - 22/05/2012 10:36 Re: ENSO Discussion 2012. [Re: Arnost]
CoastalStorm22 Offline
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Registered: 10/07/2006
Posts: 2984
Loc: Lane Cove, Sydney, NSW
Originally Posted By: Arnost
Go to the buoy summary plot and manually create a plot by chosing bouys/parameters. Its not easy but doable.

In the meantime, here's BOMs 150m basin wide temps / anomalies. There is colder water both sides of the equator - which is just a sliver af warmer water in the midst.



I'd be intrested to know what the above chart looked like in May 2009 before the onset of the last El Nino? Do you have link for for those BOM charts Arnost?
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#1105225 - 22/05/2012 12:36 Re: ENSO Discussion 2012. [Re: CoastalStorm22]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6050
Loc: Eastern A/Hills SA
That bottom chart is just what I meant Arnost, a very thin band of warmer water destined to do little and get washed away by the look!

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#1105228 - 22/05/2012 12:42 Re: ENSO Discussion 2012. [Re: CoastalStorm22]
Arnost Offline
Weatherzone Addict

Registered: 10/02/2007
Posts: 3909
Originally Posted By: CoastalStorm22
[quote=Arnost]Go to the buoy summary plot and manually create a plot by chosing bouys/parameters. Its not easy but doable.

In the meantime, here's BOMs 150m basin wide temps / anomalies. There is colder water both sides of the equator - which is just a sliver af warmer water in the midst.

I'd be intrested to know what the above chart looked like in May 2009 before the onset of the last El Nino? Do you have link for for those BOM charts Arnost?


I think I once found a publically accessible directory where the charts were archived - I may have it in my favourites at home. I'll see if I do later. Otherwise, if you have time to spare then just play around with the http:// link and see if one of the higher level directories leads somewhere... [I work on the assumption that if I can find it unprotected, its in the public domain]
_________________________
“No. Not even in the face of Armageddon. Never compromise” ...

And this of course applies to scientific principles. Never compromise these. Never! [Follow the science and you will be shown correct in the end...]

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#1105539 - 24/05/2012 00:10 Re: ENSO Discussion 2012. [Re: Arnost]
Surly Bond Offline
Weatherzone Addict

Registered: 23/08/2003
Posts: 2193
Loc: Manilla, near Tamworth NSW
Log of the Southern Oscillation Index

This graph relates to a graph of the cumulative values of the Southern Oscillation Index, posted two pages back.
This graph is in a more familiar form . It may help to explain what the earlier graph means. That is, that the SOI was dominated by positive values (towards La Nina) for about fifty-nine years before 1976, and was dominated by negative values (towards El Nino) for twenty-four years after that date. Broadly, these were straight-line relationships throughout each of the two periods, as shown by the coloured trend lines. Slopes on a CUSUM plot represent offsets of the mean value of the original data: the mean SOI in the earlier period was +1.35 units, and that in the later period was -3.4 units.
These offsets are quite large, but not as large as the offsets that define El Nino and La Nina episodes. According to the Bureau of Meteorology,
* Sustained negative values of the SOI greater than −8 often indicate El Niño episodes.
* Sustained positive values of the SOI greater than +8 are typical of a La Niña episode.
Another definition uses SOI values in the first and last deciles, which are values greater than +/-13.

The trace of the raw monthly SOI values shown on this graph could be used as an example of random "white noise" as described in Wikipedia.
Like everybody else, I try to distinguish meaningful episodes with "sustained" high positive or negative values. The red line shows values smoothed by a gaussian function of half-width six months. Many of the recognised major El Nino and La Nina episodes can then be identified.
I have transferred the trend-line construction from the earlier graph in the form of a blue line, with steps at changes in the trend. It would have been impossible to estimate the shape of the blue line without doing the CUSUM plot. After drawing the blue lines, however, one can see that the red lines do move up and down with the blue ones.
The CUSUM technique was invented specifically for early identification of sudden and persistent changes in a value. In climate, this has been called a "climate shift". The SOI has suffered three climate shifts since 1876: in 1917, 1976, and 2000.
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#1105546 - 24/05/2012 02:27 Re: ENSO Discussion 2012. [Re: Surly Bond]
Ken Kato Offline
Meteorological Motor Mouth

Registered: 05/03/2012
Posts: 6090
Great post Surly Bond. The very first thought that ran through my head when I saw that graph was that of stochastic resonance/forcing i.e. adding enough white noise in the form of individual synoptic-scale weather systems to the climate system to reveal a meaningful signal, one of the theories to try and explain the abrupt Dansgaard-Oeschger climate shift events of the past.

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#1106223 - 26/05/2012 14:17 Re: ENSO Discussion 2012. [Re: Ken Kato]
Ken Kato Offline
Meteorological Motor Mouth

Registered: 05/03/2012
Posts: 6090
My own gut feel as far as the SE QLD/NE NSW region goes, remains unchanged since earlier this year i.e. wetter/cooler (daytimes) than normal into early winter but maybe drier than normal later, encouraged by the possible lean towards the El Nino'ish side of neutral by then.

Also, my subjective impression is that winter seems to be shifting forward earlier & earlier in recent years during ENSO-neutral (or thereabouts) years i.e. anomalously cold/wet conditions occurring around late autumn/early winter before suddenly shifting to anomalously warm/dry conditions from midwinter. Anyway just a wild thought.

My reasoning for the cool wet signal for early winter is due to warm SST anomalies off northern Australia, particularly pronounced around the Gulf of Carpentaria - this could encourage more moisture to stream down from the tropics if approaching synoptic systems co-operate. The Bureau's statistically-based seasonal outlook map also suggests moderate odds for wetter than normal conditions albeit averaged over winter.

Meanwhile, a number of dynamical models, as indicated by multi-model ensembles including EC, JMA, etc, are suggesting the possibility of drier than normal conditions in this region later in winter. Example from the APCC ensemble for Aug below:


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#1106226 - 26/05/2012 14:37 Re: ENSO Discussion 2012. [Re: Ken Kato]
Surly Bond Offline
Weatherzone Addict

Registered: 23/08/2003
Posts: 2193
Loc: Manilla, near Tamworth NSW
Returning the compliment, Ken.K.
Your post is written so I can understand it.
Not many posts are.
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#1106543 - 28/05/2012 12:29 Re: ENSO Discussion 2012. [Re: Surly Bond]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1745
We keep hearing and reading we are going into a Negative IOD phase but this begs to differ looks like by the ssts anomalies here we are about to go into a Positive IOD phase as we start Winter

http://www.weatherzone.com.au/climate/indicator_sst.jsp?c=ssta
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#1106549 - 28/05/2012 13:30 Re: ENSO Discussion 2012. [Re: _Johnno_]
Twister1 Offline
Weather Freak

Registered: 30/12/2006
Posts: 586
Loc: Chadstone Vic
That is a lot of Cold water and these Dry Cold SE Surges North are NOT helping

Not Good news lets hope these cut offs happen alot this winter as think it be another year of little front action
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#1106553 - 28/05/2012 13:55 Re: ENSO Discussion 2012. [Re: Twister1]
bd bucketingdown Offline
Meteorological Motor Mouth

Registered: 07/02/2008
Posts: 6050
Loc: Eastern A/Hills SA
This is encouraging the cold ocean temps up there with cold off shore winds and up-welling of cold water through that off shore wind also...(as TT suggests)
Record cold hits WA Kimberley
Brett Dutschke, Monday May 28, 2012 - 09:49 EST

Western Australia's Kimberley has been shivering during the last few nights as record-breaking cold hits the region.

On Saturday and Sunday night much of the region experienced its lowest May temperatures in more than a decade. Broome has broken the record twice in two nights, dipping to 8.1 degrees on Saturday night then 7.7 last night, both more than 10 degrees below average.

On Sunday night Fitzroy Crossing was one of the coldest centres, getting as cold as 6.0 degrees, also 10 below average. This is its coldest May night in at least 15 years.

West Roebuck dipped to 6.2 degrees on Sunday night after a chilling 5.5 on Saturday night, which was its coldest May night in at least 13 years.

Saturday night was also the coldest for May in more than a decade for Mt Elizabeth and Wyndham airport, cooling to 0.5 and 9.6 degrees respectively.

Dry southeasterly winds have been affecting the Kimberley and much of WA for a week now and have combined with mostly clear skies to bring colder-than-average nights.

Nights have also been noticeably cold in the south of the state, where Perth had its equal coldest May night in more than 100 years of records. It got as low was 1.3 degrees last Thursday night, equalling the record May low, set in 1913.

Sunday night was Esperance's coldest May night in five years, recording a minimum of 6.5 degrees, five below average...."



Edited by bd bucketingdown (28/05/2012 13:56)

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#1106835 - 30/05/2012 14:11 Re: ENSO Discussion 2012. [Re: _Johnno_]
Chris Stumer Offline
Weatherzone Addict

Registered: 28/01/2010
Posts: 1883
Loc: Kingaroy
but we've had one positive IOD after another, something must have happened to the ocean currents up there, that big earthquake and tsunami back in 2004 might have done something, let's hope that JAMSTEC is right and we do get a negative IOD this year.

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#1106861 - 30/05/2012 17:36 Re: ENSO Discussion 2012. [Re: Chris Stumer]
Arnost Offline
Weatherzone Addict

Registered: 10/02/2007
Posts: 3909
Not so sure we can say we've had a positive IOD after another:

_________________________
“No. Not even in the face of Armageddon. Never compromise” ...

And this of course applies to scientific principles. Never compromise these. Never! [Follow the science and you will be shown correct in the end...]

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#1106868 - 30/05/2012 18:11 Re: ENSO Discussion 2012. [Re: Arnost]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1745
2006, 2007 & 2008 were all regarded as Positive IOD's by the BOM and the colder than normal waters through Winter and Spring all those Years NW of OZ and through Java and Sumatra back that up


Edited by _Johnno_ (30/05/2012 18:11)
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