|SA Seasonal Rainfall Outlook: probabilities for November 2004 to January 2005, issued 19th October 2004|
Generally neutral odds for SA seasonal rainfall
In South Australia there are no strong shifts in the odds towards either above or below average totals for the late spring to mid-summer quarter (Nov-Jan), the Bureau of Meteorology announced today. This is despite the fact that below average seasonal rainfall is favoured for parts of Queensland and NSW.
Across SA, the chances of above median rainfall for the November to January period are mainly between 45 and 50%. So in years with ocean patterns like the current, about five November to January periods out of ten are expected to be drier than average over the State, with about five out of ten being wetter.
The current pattern of outlook probabilities is mainly due to increasing warmth in the Pacific Ocean.
Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During the November to January quarter, history shows this influence to be only weakly consistent across much of South Australia (see background information).
Progress towards a late-developing El Niño event has slowed over the past month, with consistent cloud and wind patterns failing to materialize. The central Pacific remains warmer than average and at levels consistent with El Niño, but the Southern Oscillation Index (SOI) was only weakly negative coming in at 3 for September. The approximate SOI for the 30 days ending 16th October was 5.
For routine updates on the latest data relating to El Niño, together with details on what the phenomenon is and how it has affected Australia in the past, see the El Niño Wrap-Up.
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|More information on this outlook is available from 9.00am to 5.00pm (CST) Monday to Friday by contacting the Climate and Consultancy section in the Bureau's Adelaide Office: (08) 8366 2664.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 19th NOVEMBER 2004.