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#1469021 - 18/08/2018 00:41 Latest outlook for SA
MGD Offline
Cloud Gazer

Registered: 13/06/2017
Posts: 15
Loc: Heathfield SA
Just looking at the latest 3 month outlook from the BOM I am a bit confused as to how it was arrived at.. Currently there is a very severe drought in NSW and also parts of Victoria and northern SA but coastal areas in the south have been spared and have been in fact quite wet this month. SAM seems to be responsible. The outlook was suggesting more of the same over the next 3/12 with possible el-nino and unfavorable Indian Ocean temperatures with again only the far southern coastal areas being spared. Yet the forecast shows the worst of the dry areas to be SW Victoria and SE SA in the next 3 months. How did they arrive at this conclusion as there is no explanation? I notice coastal NSW returning to more normal rainfalls so what is happening? Without being too critical they have got August wrong for Southern SA with many areas already reaching average and with 2 weeks left likely to surpass average so I do not have great confidence in their outlooks ( just as well because it is dismal for southern SA )

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#1469023 - 18/08/2018 00:54 Re: Latest outlook for SA [Re: MGD]
Eevo Offline
Weatherzone Addict

Registered: 02/11/2013
Posts: 1655
Loc: Bridgewater
zero faith after they said a dry outlook and it turned out to be one of the wettest years on record.

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#1469055 - 18/08/2018 16:57 Re: Latest outlook for SA [Re: MGD]
Anthony Violi Offline
Weatherzone Addict

Registered: 06/11/2001
Posts: 2336
Loc: Mt Barker - SA
Exactly the same MGD, you cant have both pieces of the pie. To be drier in the South it implies positive AAO. Clearly they don't know about teleconnections with the MJO, or Central Pacific in winter. And now we have the very embarrassing situation where this el nino, if it even develops by the numbers, is not connected with the atmosphere. The AAO has been negative and is likely to stay there in the short term until October.

This weeks trade wind burst will bring in quite a bit of upwelling of the South American coast, enhancing the cooler waters here, and putting a lid on the downwelling Kelvin Wave for a little while. Its likely to still warm, but I cant see how it will reach El nino status before Xmas at this rate, and I am not forecasting it to have any impact, in fact I believe the opposite, a weak negative IOD is going to develop, and enhance September rainfall.

It may go dry again, I have considerably less rain for October forecast, but will take a look at the end of the month how the set up looks, right now the Nino 4 region is the only one that is warm, the rest are cooling, except for Nino 1 and 2 this week which has had a bit of an uptick.


Edited by Anthony Violi (18/08/2018 16:58)
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#1469056 - 18/08/2018 17:01 Re: Latest outlook for SA [Re: MGD]
Kino Offline
Weatherzone Addict

Registered: 10/08/2017
Posts: 2618
Loc: Wollongong, NSW, Aus
Every outlook from the BoM is drier and warmer. They donít change.


Edited by Kino (18/08/2018 17:02)

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#1469059 - 18/08/2018 17:08 Re: Latest outlook for SA [Re: MGD]
Anthony Violi Offline
Weatherzone Addict

Registered: 06/11/2001
Posts: 2336
Loc: Mt Barker - SA
As far as temps go, take that with a grain of salt, pretty sure its measured against 1961-1990, exaggerating the warming. But regardless, they did have a drier winter inland which was correct mostly, but I think their September forecast is under serious heat. When do you see WA have low rainfall when its also low in the East? The SW corner especially shows weak La Nina/IOD signals, I have been forecasting it go dry their by the start of September and its already begun.
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#1469296 - 21/08/2018 19:21 Re: Latest outlook for SA [Re: MGD]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7583
Loc: Adelaide Hills
As a rough guide, if one wants a forecast for their backyard / local town, looking at regional outlooks which are on different space and time scales is probably not the way to go smile .

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#1469345 - 22/08/2018 21:23 Re: Latest outlook for SA [Re: MGD]
Seira Offline
Meteorological Motor Mouth

Registered: 27/08/2003
Posts: 7583
Loc: Adelaide Hills
Originally Posted By: MGD
Currently there is a very severe drought in NSW and also parts of Victoria and northern SA but coastal areas in the south have been spared and have been in fact quite wet this month.

Regarding rainfall being closer to average nearer coasts rather than inland smile would likely be because sources of moisture (i.e. oceans / seas) are right next to the coasts, whereas inland areas are...inland, further away from moisture, and therefore it takes longer for humidity to get there (when it does).

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