|SA Seasonal Rainfall Outlook: probabilities for October to December 2005, issued 15th September 2005|
Odds generally 50:50 for a wetter than average season in SA
The odds for a wetter than average December quarter (October to December) are close to 50:50 over most of South Australia, the Bureau of Meteorology announced today. However, in the far southeast of the State the odds have swung in favour of the three-month rainfall total being below the median.
For the October to December period, the chances of above median rainfall are between 35 and 40% in the far southeast of SA (see map). This area has been suffering severe short-term rainfall deficiencies since the start of autumn. See the Drought Statement for more information.
So in years with ocean patterns like the current, about four December quarters out of ten are expected to be wetter than the median over this part of South Australia, with about six out of ten being drier.
Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During the December quarter, history shows this influence to be moderately consistent across the eastern half of SA, but only weakly consistent in the west (see background information).
The Southern Oscillation Index (SOI) fell from +1 in July to −7 in August. However, the SOI has begun to rise again with the approximate value for the 30 days ending 12th September being −1.
With all the main tropical Pacific climate indicators remaining neutral, an El Niño event developing in 2005 is not considered a realistic possibility. For routine updates and comprehensive discussion 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 ENSO Wrap-Up.
Click on the map above for a larger version of the map. Use the reload/refresh button to ensure the latest forecast map is displayed.
|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 18th OCTOBER 2005