Page 36 of 45 < 1 2 ... 34 35 36 37 38 ... 44 45 >
Topic Options
#1015535 - 29/09/2011 01:16 Re: The Indian Ocean Dipole and the season ahead. [Re: ROM]
ROM Offline
Meteorological Motor Mouth

Registered: 29/01/2007
Posts: 6425
As many of you already know there are a whole series of surface currebnts and sub surface counter curewnts around australia's southern and western coasts with a strong subsurface westward flowing counter current running partly under the south and easterly flowing Leeuwin current.
This does lead to a whole matrix of currents and counter currents flowing in and around the main straits through the Indonesian archipelago which in turn leads to all sorts of differing ocean temperature regimes at the surface and below in the sub surface in this area.
The ARGO floats in Australia's regions are mapping these surface and sub surface ocean water masses for both temperature and salinity.

A couple of sources for this info and the local ARGO float profiles in and around to the south of Indonesia can be found at these sites; IMOS > Ocean Portal.
Click on ARGO floats in the LH column and then a float somewhere and you will get that float's dive profile if you click "latest Dive Profile Graph".

Or you can short cut it by going to this previous and alternative site which now also is under IMOS.

Go and have some fun working out the huge range and changes in the subsurface pool's temps and salinity profiles over quite short ocean distances in that Australian NW ocean regions.

Top
#1015864 - 30/09/2011 01:31 Re: The Indian Ocean Dipole and the season ahead. [Re: ROM]
S .O. Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1266
Loc: Southern Victoria
The cut off , hovering west of the west coast of WA , is drawing down some cloud/precip from Near Sumatra . And the Western Equatorial Pacific is really starting to pump out some convective clouds late this week . I'm not sure how long this positive will last . Another week of clear skies , building humidity , low pressure and little in the way of seaborne winds will no doubt help the SST's start climbing . Nina's going to start hacking into that + IOD .
_________________________
" I walk around in the Summertime , saying ' how about this Heat ' !
I'm an ............ , a real ........ ............. "

Top
#1016860 - 04/10/2011 00:07 Re: The Indian Ocean Dipole and the season ahead. [Re: S .O.]
S .O. Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1266
Loc: Southern Victoria
Way out on the edge of " The Models :- Nevernever period ( 160 hrs < ) " .

We may have a solid NW Tropical infeed , from an area nearing the southern end of Sumatra down to somewhere in the Middle of WA .
It's a long way out , but may be connected with the fallout of The latest Typhoon in the South China Sea . That being the case , could be the first ' real ' transition of Moisture from NH to SH within the Maritime quarter this Spring .
If it does come off anything like forecast ( or at all ) , it won't matter what it does when it reaches AUS , it will only add to the complexity of things as we are now staring down the Barrel of perhaps this being the Fifth Trough to Sweep From The West in a East/SthEast Direction .
The current one centred on the Norseman/ Nullarbor region , and born as mentioned in above post being the Third . Of which had very little , but just visible infeed , but more out towards the central IO .


Edited by Southern Oracle (04/10/2011 00:08)
_________________________
" I walk around in the Summertime , saying ' how about this Heat ' !
I'm an ............ , a real ........ ............. "

Top
#1018310 - 09/10/2011 21:35 Re: The Indian Ocean Dipole and the season ahead. [Re: S .O.]
S .O. Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1266
Loc: Southern Victoria
Said moisture visible on the current IR sat picture feeding down over Sumatra & Java . By the looks of it this will act as some of the fuel for late this weeks Qld precip event . !?
_________________________
" I walk around in the Summertime , saying ' how about this Heat ' !
I'm an ............ , a real ........ ............. "

Top
#1018428 - 10/10/2011 14:12 Re: The Indian Ocean Dipole and the season ahead. [Re: S .O.]
ROM Offline
Meteorological Motor Mouth

Registered: 29/01/2007
Posts: 6425
That water vapour band heading SE out of the western areas of the Maritime Continent at the moment is most likely the result of the current MJO phase.
On the sat pics note the huge gap in the central Indian Ocean that has developed in the westerly equatorial flow from out of the Pacific Warm Pool so that westerly flow of high water vapour content air mass has been diverted down SE across Australia for the moment.

From the BOM's "Weekly Tropical Climate Note" 4th Oct.
Quote:
A weak MJO over the eastern Maritime Continent
A weak Madden-Julian Oscillation (MJO) pulse has propagated east across the northern Maritime Continent over the past week, but has stalled once more over the eastern Maritime Continent/western Pacific Ocean. Similar to last week, the weak MJO pulse intensified as the eastern flank of the northern hemisphere monsoon trough continues to gain strength with the development of Typhoon Nalgae. Guidance from climate models suggests this MJO pulse will remain weak as it continues to propagate east across the Pacific Ocean and into the western hemisphere over the next fortnight.
The eastward propagation of the MJO has contributed to the attrition of the Southwest Monsoon over the Indian sub-continent and an abrupt strengthening of the Northeast Monsoon over South-east Asia.
Although enhanced convection continues near 60 °E, it has contracted and weakened over the past week. An area of suppressed convection persists near 90 °E (west of Sumatra) and has now extended to western Bay of Bengal and India. These factors continue to be indicative of a weak, positive Indian Ocean Dipole. Positive IOD events have been associated with drier conditions over parts of Australia, particularly central and southeastern Australia during winter and spring.
Across northern Australia, a trough will sweep over the country during the next week, bringing rain and a cooler change to the central regions. This will lead to a break in the fire weather conditions that have been experienced over the past few weeks across the red centre. Further north, an easterly flow will keep humidity levels and temperatures high, leading to increasing rainfall activity.

The high levels of Outgoing Long wave Radiation [ OLR ] in the current OLR charts also indicate relatively clear skies in those longitudes across the eastern Arabian Sea to the west of India which backs the BOM's analysis up.

Madden Julian Oscillation per BOM

Top
#1086825 - 07/03/2012 22:16 Re: The Indian Ocean Dipole and the season ahead. [Re: ROM]
S .O. Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1266
Loc: Southern Victoria
It is fast approaching that Time of year again when Indian Ocean Waters off NWA ( not the RAP group ) , will influence SE Australia's Precipitation Patterns .

I noted that many were discussing IOD in other Threads including The MDB .

Jamstec , are favouring a weak Negative This coming Winter - Spring . Which shall be interesting as this is already showing signs , and the La Nina Coupling will be a Magnifier untill it eases ( and some say go Nino ) or worst still for MDB stay abate then return strong Nina again to take up where the - IOD will finish off .
_________________________
" I walk around in the Summertime , saying ' how about this Heat ' !
I'm an ............ , a real ........ ............. "

Top
#1089861 - 15/03/2012 21:19 Re: The Indian Ocean Dipole and the season ahead. [Re: S .O.]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Just a bump smile

Top
#1089865 - 15/03/2012 21:23 Re: The Indian Ocean Dipole and the season ahead. [Re: adon]
Arnost Offline
Weatherzone Addict

Registered: 10/02/2007
Posts: 3572
Loc: Just a bit north of the "coath...
And about time - I'm surprised that nobody is onto this. I guess ROM the IOD King is too busy chasing trolls. LOL.
_________________________
Exceptions are pernicious, they conceal laws...

Top
#1093124 - 20/03/2012 07:47 Re: The Indian Ocean Dipole and the season ahead. [Re: Arnost]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Johno was saying JAMSTEC has been onto a neg IOD for six months now so fingers crossed it holds. It has a nasty habbit of a 180 flip in April.

Top
#1102109 - 30/04/2012 22:40 Re: The Indian Ocean Dipole and the season ahead. [Re: adon]
S .O. Offline
Weatherzone Addict

Registered: 31/01/2011
Posts: 1266
Loc: Southern Victoria
I think April is almost over Guys ....

Where do we think this is heading ?/?
_________________________
" I walk around in the Summertime , saying ' how about this Heat ' !
I'm an ............ , a real ........ ............. "

Top
#1102358 - 02/05/2012 12:42 Re: The Indian Ocean Dipole and the season ahead. [Re: S .O.]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Waiting till the may JAMSTEC to come out, it's was saying negative in April so hoping it won't change in may

Top
#1102361 - 02/05/2012 13:11 Re: The Indian Ocean Dipole and the season ahead. [Re: adon]
_Johnno_ Offline
Weatherzone Addict

Registered: 08/11/2009
Posts: 1133
Wheres ROM these days?? hasn't made a comment in here in 6-7 months!! Too busy in the other threads I'm guessing. Cmon ROM this is your bread and butter stuff! Love to hear your opinion


Edited by _Johnno_ (02/05/2012 13:11)

Top
#1102395 - 02/05/2012 15:59 Re: The Indian Ocean Dipole and the season ahead. [Re: _Johnno_]
ROM Offline
Meteorological Motor Mouth

Registered: 29/01/2007
Posts: 6425
Yeh! Your'e right Johnno. Gotta get my teeth into this sometime so i had better start looking at some of the stuff on the IODipole as it is the Weather Maker, to borrow a phrase from Flim Flannery, or the winter and spring season in SA. western and even as far as the central Vic regions.

There has been a shift in the IO's SSTs towards a slight warming in the western IO but also a slight warming in the eastern pole of the IOD regions.
Looks like neutral to me at this stage but I will have to come back and study it all before I really can have any opinion.

It's all a bit difficult when the SST's are very near that neutral range if one consults the NOAA / NESDIS SST anomaly map as there is an abrupt change in colours from yellow to blue when the SST's get above or slightly below the neutral SST mark.

At least that map is smoothed over a few days whereas the UNISYS map is a daily map with all the ups and downs that implies.

Will be back.


Edited by ROM (02/05/2012 16:01)

Top
#1104026 - 13/05/2012 18:57 Re: The Indian Ocean Dipole and the season ahead. [Re: ROM]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Any news ROM....


Edited by adon (13/05/2012 18:57)

Top
#1104051 - 13/05/2012 22:47 Re: The Indian Ocean Dipole and the season ahead. [Re: adon]
ROM Offline
Meteorological Motor Mouth

Registered: 29/01/2007
Posts: 6425
You guys are putting the pressure on grin
I've been busy chasing professional trolls hell bent on disrupting a perfectly good forum lately as some of you might have noticed.

Ok!. I've been poking around a bit into the local WA and south of Java region ARGO float arrays [click a float to get the output & explanations are bottom "real time processing" ] to try and see if much was happening down under the surface.
Another source for local ARGO float data is the Australian Ocean Data Network.
If you click through a float here and there are lots of things to explore on this site, it will give the location and the all important ARGO ID number of the float.
Say in this case float ID 5900 146 which is located some 600 or 700 kms south west of Sumatra.
Clicking through the floats "Latest Profile Graphs" takes you back to IMOS page.
Click through "Temperature and salinity down to 2000 metres" and when the map comes up just click on the bracketed WMO number on top and then find your float number in the series.

Or simpler just take down the float ID and go straight to the Float ID series,find your float and click for the temperature and salinity profile.
thats if the float you have selected is listed as reporting in during the last month as by now many, many of the 3000 floats have dissappeared or became non operational as battery life is exhausted after their initial deployment starting in 2003 but with replacements ongoing since.

The AMSR- E satellite which was used for another angle to the ARGO system and as a contrasting technology to measure a very limited distance under the surface for water temps with it's Advanced Microwave Scanning Radiometer system has given up the ghost to considerable consternation from a lot of quarters which had come to rely [ too much ] on the 9 year old sat.
So there are some gaps in the data coming in from the world's oceans now until a new sat is deployed in a another year or so.

All in all, there doesn't seem to much happening sub surface in the eastern Indian Ocean from the ARGO array.

The Western Australian Dept of Ag's Growing Season Outlook for April is suggesting average winter rains for the eastern states grain areas.
Colder than normal waters are off the NW Australian coast but warmer than normal waters are down near the SW Australian coast.

The WA Australian forecast maps; The level of forecasting skill map is on the right


The NOAA SST maps confirm the cooler waters off the NW coast, a situation that hasn't really changed for the last month or so.
The abrupt switch in colour at the zero anomaly point in the NOAA SST maps does lead to a false view on the differences in the SST's between areas.

A different and daily SST map which I hadn't come across before which is far more subtle in it's colour contrasts and probably conveys a better balance to the viewer of the differences in the SST's can be found here.
http://www.oceanweather.com/data/

Another map that I also hadn't come across before in the CPC site provides a few clues on what the CPC thinks might be the short term outcomes in the IO.
It is from the CPC's Global Tropical Hazards Outlook page.


Quote:
Last Updated: 05.08.12 Valid: 05.09.12 - 05.22.12
The MJO remained incoherent during the past week and anomalous tropical convection is scattered and generally unorganized on the large scale. The enhanced phase of an equatorial Rossby wave (ERW) is continuing to shift westward across Africa. Enhanced convection was observed over portions of northern South America and the southern Maritime continent, with suppressed convection across parts of the Indian Ocean. Tropical cyclone 19S developed north of Australia during the past week, but this system has already weakened.

Most of the dynamical model forecasts of the MJO index indicate very weak and incoherent signals during the next two weeks, so the MJO did not play any substantial role in the forecast this week. La Nina has transitioned to ENSO neutral conditions and this along with incoherent MJO activity makes the outlook primarily driven by numerical model guidance.

Enhanced rainfall is favored across much of central Africa from the Atlantic coastal areas across the central portion of the continent to the Greater Horn of Africa and is based on model guidance as well as the enhanced phase of the ERW. Greater than average odds for below-median rainfall is indicated across southern India, parts of the central and eastern Indian Ocean, primarily north of the equator and also over areas in nrothern South America. Wetter-than-average conditions are favored for portions of the southern Maritime continent (in part related to the remnants of TS19), the Caribbean, eastern Mexico and the Gulf coast states in the southern U.S. mainly based on model guidance. Above-average SST's also favor above-average rainfall for northwest South America.

During Week-2, there is lower coverage as a result of little MJO signal and the absence of La Nina. Enhanced rainfall is favored for parts of the Gulf of Guinea region in Africa associated with model guidance and the enhanced phase of the ERW. There are enhanced odds for above-average rainfall for portions of Central America and northwest South America where above-normal SSTs and model guidance indicate continued wetness. Model guidance favors below-median rainfall for an area in close proximity to the Philippines


Almost a hint of an extremely weak pos-IOD hint there in that map but nothing to really hang one's hat on in the way of a prediction.

And finally you have Bob Tisdales take on it all and he isn't biting at all as to what is going to happen this season.
La Nada, El Niņo, or Three-Peat La Niņa for 2012/13 ENSO Season?

My take is that we are heading for a very near neutral year re the IOD as something should be starting to turn up in the SST's by now although the IOD of whatever colour doesn't normally get wound up until into July.
The ENSO also looks like it might almost be a non event as it too should be showing some more serious signs of drifting one way or another .

If anything maybe a very weak El Nino which would be typical of a negative PDO phase and which is likely to be the future of the ENSO El Nino phase for most of the next 30 years or so while the PDO stays negative.
This would explain the Western Australians suggestion that Queensland might be a bit on the dry side but the SE will probably get an average season what ever that is these days as a very weak El Nino effects just don't penetrate into the western side of Vic very much or at least westward past say the Pyrenees range in central west Vic.

And for some reason, maybe the SAM phase at the moment, the water vapour out of the western Pacific Warm Pool is staying up around the equator and is not feeding down into the Southern areas of the IO. Until that starts to happen we just sit on our hands and wait as without that infeed from the westerly flowing water vapour and winds in the equatorial regions, any rain we get here in the SE will be quite light at least in the western parts of the state.
And the rainfall in the SE won't be helped by the intensifying cold of this season so far.
Sadly I strongly suspect that we had better get use to the cold if the Russians and a whole range of solar physicists are right about future solar activity.
And with cold comes dry air and reduced rainfall in man but not all regions.
But where we won't know for quite a few years yet.

I'll be back soon for another go at this so be gentle if I am wrong as usual. confused

Top
#1104075 - 14/05/2012 08:44 Re: The Indian Ocean Dipole and the season ahead. [Re: ROM]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Thanks ROM must have taken most of the night to come up with all that! wink Yeah getting quite late for a rain for all of the canola that has been sown around here and will take a big yield hit of it does not rain by June. Sheep feed for those who push it is running out and farmers are getting twitchy. I reckon if you looked at most of the browsing history of the farmers around here, 90% of it would be weather related atm! Only thing I can add is that the IO is starting to cool south of WA and From memory that will help cold fronts come up into the continent with more punch and hopefully link up to some moisture in the tropics.

Top
#1104077 - 14/05/2012 08:49 Re: The Indian Ocean Dipole and the season ahead. [Re: ROM]
ROM Offline
Meteorological Motor Mouth

Registered: 29/01/2007
Posts: 6425
For what it is worth!
The SAM index has reluctantly gone negative again over the last few days.
It seems that a rain event will often pass through the SE around ten days to a fortnight after the SAM index has reached a low negative index.
A low SAM index means that the atmospheric based SAM around Antarctica has expanded and the frontal systems and low pressure tracks are being pushed north some way which puts the SE in the path of the more intensive parts of the lows and fronts.

Hopefully, being a little further north the fronts and troughs will pick up an infeed of moisture from the tropics which will track down along the fronts and with the more intensive frontal lift nearer the centre of the low pressure, will provide enough uplift to give the SE a few good bursts of rain and heavy showers as the fronts and troughs pass through.

There was a substantial dip in the SAM index during mid February and a very moderate rain event [ at least for west Vic ] occurred in the first few days of March or about a fortnight after the dip in the SAM index, a seemingly fairly common occurrence from my observations following a good prolonged and substantial dip in the SAM index.

And the GFS 14 day forecast which is normally hardly worth the trouble of looking at has also got enthusiastic about a rain event during the last couple of runs with wide areas of precipitation predicted across SE Oz late in the 14 day forecast period so we will watch to see if this holds for the next few days.
Usually it just boils off in this 14 day GFS forecast after a few runs and we wait again but hope springs eternal.

It needs to as sowing of the crops is well underway here in western Vic and rain and lots of it is urgently needed by farmers as the surface is very dry although there are quite good reserves of moisture a half metre down in a lot of areas, still there from the 200 mm sprinkle we got in early 2011.

Top
#1104122 - 14/05/2012 14:52 Re: The Indian Ocean Dipole and the season ahead. [Re: adon]
ant Offline
Meteorological Motor Mouth

Registered: 05/10/2002
Posts: 8590
Loc: Overlooking ACT at 848m
Originally Posted By: adon
and farmers are getting twitchy.


I am, too. Whenever we get a prolongued dry spell, I get twitchy. And when it's accompanied by an onset of cold, I twitch even more. The ground has well and truly dried out, the levels on the dams are falling noticeably, the cold plus the dry means no more feed is growing. I still don't think our weather is back to what used to be "normal" and I see drought around every corner. I know the people in northern NSW/Southern QLD are sick of rain, but if we don't get some every few weeks, I worry.

Top
#1104124 - 14/05/2012 15:07 Re: The Indian Ocean Dipole and the season ahead. [Re: ant]
adon Offline
Meteorological Motor Mouth

Registered: 19/08/2004
Posts: 5038
Loc: Not tellin!
Where do you get the SAM index from ROM? Would like to keep an eye on that too

Top
#1104128 - 14/05/2012 15:27 Re: The Indian Ocean Dipole and the season ahead. [Re: adon]
ROM Offline
Meteorological Motor Mouth

Registered: 29/01/2007
Posts: 6425
Try this one Adon which is the site I get the SAM index from which is also called the AAO. [ Antarctica Oscillation ]

You will find links to the other major weather and climate oscillations on the Left

http://www.cpc.ncep.noaa.gov/products/precip/CWlink/ENSO/verf/new.aao.shtml

And the AAO / SAM outlook from that LH panel;

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

Top
Page 36 of 45 < 1 2 ... 34 35 36 37 38 ... 44 45 >


Who's Online
11 registered (Rolling thunder, Macca-wx, Things, split_city, Ms Milo, ColdsnapIII, sswanss, 4 invisible), 141 Guests and 49 Spiders online.
Key: Admin, Global Mod, Mod
Today's Birthdays
AussiePride_oioi, Bree, celina amina, Squaremeaters, Stazza_Brendan
Forum Stats
27418 Members
32 Forums
21908 Topics
1225959 Posts

Max Online: 2925 @ 02/02/2011 22:23
Satellite Image
Advertisement