Climate Driver Discussion 2019 (Enso, IOD, PDO , SAM)

All general weather related discussion & questions, including model discussions, longer-term outlooks & anything non-breaking weather.

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weathergasm
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Wed Nov 06, 2019 11:50 am

All those upper troughs won’t do us much good if they’re not meeting up with some tropical moisture, so here’s hoping the +IOD breaks down sooner rather than later.
StratoBendigo
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Wed Nov 06, 2019 4:35 pm

weathergasm wrote:
Wed Nov 06, 2019 11:50 am
All those upper troughs won’t do us much good if they’re not meeting up with some tropical moisture, so here’s hoping the +IOD breaks down sooner rather than later.
Indian Ocean Dipole is around +2c atm. Probably won't go neutral until after January.

The Central Indian Ocean is rather hot at present, which might convey some moisture into Southern Australia.
JasmineStorm
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Wed Nov 06, 2019 5:02 pm

weathergasm wrote:
Wed Nov 06, 2019 11:50 am
All those upper troughs won’t do us much good if they’re not meeting up with some tropical moisture, so here’s hoping the +IOD breaks down sooner rather than later.
It already has met moisture. That's what triggered the inland rain and storms over NSW, QLD and Vic so far in Nov.
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StratoBendigo
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Thu Nov 07, 2019 10:54 am

These strong Westerlies have dumped huge quantities of dust from the Simpson Desert and inland Australia into the Tasman Sea off NSW this morning.

Satpic is bonkers!
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Didjman
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Thu Nov 07, 2019 6:04 pm

The dust can still be seen out there in the Tasman!
StratoBendigo
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Fri Nov 08, 2019 9:49 am

Much of Vic has done well for rain in past week because of:
1) Strongly -ve AAO
2) MJO in Phase 5
3) LWT in the right spot.

Triple whammy.
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Didjman
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Fri Nov 08, 2019 6:53 pm

We can thank the SSW event back in August / September for pushing back the fire season in parts of SA and all of Vic / Tas. The same event that is scorching NSW though :o
weathergasm
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Wed Nov 20, 2019 6:36 pm

I think the front tomorrow is going to be very typical of the kind of moisture-sapped, gusty cold front we’ll see a lot of this summer here in Melbourne. Until at least January it seems - the BOM have said in their latest tropical update there is no sign of any monsoon trough south of the equator, and therefore very little tropical moisture of the kind we need for good rains unless we get lucky (as we did earlier this month).

Kind of depressing!
StratoBendigo
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Thu Nov 28, 2019 3:58 pm

BOM Outlook for summer is out. Going for a damp WA, and dry Eastern Seaboard. Hot everywhere.
JeremyP
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Sun Dec 08, 2019 9:35 am

Hello Weatherybods,

Thought I'd try out my weather eyes, and see if anyone here has a finger on the pulse of how southern South America is experiencing this extended negative SAM? I would guess that the pattern of Lows would be staying more northerly than would be usual, and possibly bringing more precipitation with it, but not having a feel for the "usual" for that region I thought I'd check in here :)

Would also add I've really enjoyed finding this forum, and floating around to see what meteorological gems I can glean!

Thanks :)
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Sean
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Tue Dec 10, 2019 12:09 am

Didjman wrote:
Tue Oct 01, 2019 6:11 pm
weathergasm wrote:
Tue Oct 01, 2019 5:44 pm
Latest ENSO wrap-up from BOM released today indicates positive IOD going from strength to strength:

“The Indian Ocean Dipole (IOD) remains positive, with the latest weekly index value to 29 September at +1.76 °C. This is the highest weekly value observed in the Bureau's dataset which extends from 2001 to present. Last week's value of +1.50 °C is the second highest on record.”

http://www.bom.gov.au/climate/enso/#tabs=Indian-Ocean

Not good news for those of us in the southeast in the next few months, at least. I’m very pessimistic about the chances of good rains before Christmas.
Couple that with SAM going -ve, and we have bad fire weather!
This prospect sure came to fruition. What a shocking start to the fire season.
StratoBendigo
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Thu Dec 12, 2019 4:09 pm

It's nice to see the +ve IOD finally dissipating. Water is boiling between Darwin and Timor at present, so something's got to give soon....
Sean
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Fri Dec 13, 2019 11:17 pm

StratoBendigo wrote:
Thu Dec 12, 2019 4:09 pm
It's nice to see the +ve IOD finally dissipating. Water is boiling between Darwin and Timor at present, so something's got to give soon....
What's the bet it's going to be dramatic given that it's a never ending run of extremes these days?

It feels like good rains are a thing of the past, yet it also seems like a switch will flick and the continent will be inundated at some point given how strong these climate drivers have been.
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windyrob
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Wed Dec 18, 2019 7:58 am

This might be of interest.
https://judithcurry.com/2019/09/01/enso ... -activity/

From what I can determine solar appears to drive alterations in the brewer Dobson circulation that weaken trade winds/polar vortex during the descending phase of the cycle (like stratospheric autumn) while doing the opposite during the ascending phase. That probably means we won’t see La Niña till 2021 with the deep solar minimum we are having.

Also a good paper on the post hiatus warming indicating it was driven by cloud changes related to PDO.
https://res.mdpi.com/d_attachment/clima ... -00062.pdf
StratoBendigo
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Wed Dec 18, 2019 2:01 pm

The extremely hot water temps of the NW coast of Australia is raising eyebrows (warmest since Feb 2011).
https://www.abc.net.au/news/2019-12-18/ ... e/11808268

Perhaps a spectacular tropical downpour on the cards in the coming weeks/months? Something's gotta give....
Sean
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Fri Dec 20, 2019 12:57 am

StratoBendigo wrote:
Wed Dec 18, 2019 2:01 pm
The extremely hot water temps of the NW coast of Australia is raising eyebrows (warmest since Feb 2011).
https://www.abc.net.au/news/2019-12-18/ ... e/11808268

Perhaps a spectacular tropical downpour on the cards in the coming weeks/months? Something's gotta give....
Came here to note the same thing. If the winds reverse, those rains flooding eastern Africa may start dumping on Australia. It's not a given, but the potential is there.

We just have to wait and see whether the temperature differential is enough to see the winds change direction (pray for a sudden cooling event in the eastern Indian ocean lol!)
StratoBendigo
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Sat Dec 21, 2019 9:46 am

MJO pulse is still several weeks away from being in the right zone. It was good last week but ITCZ was still way North (Equatorial).

Maybe something mid-late January. Horrifically hot in the meantime.
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Didjman
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Sat Dec 21, 2019 10:36 am

IOD is coming down (SSTs are almost the same across the IO), but SAM is still negative.
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Didjman
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Wed Dec 25, 2019 10:19 am

Current IOD:
Image


Current SAM:
Image


Current IO SST anomalies:
Image

We just need the monsoon to fire up and our storm season might belatedly commence :D
JasmineStorm
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Thu Dec 26, 2019 12:05 pm

The floods are coming.
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