SA Seasonal Rainfall Outlook: probabilities for October to December 2003, issued 16th September 2003

Varied odds for SA seasonal rainfall

The Bureau's rainfall outlook for the December quarter shows a generally neutral, although varying pattern of odds over South Australia. This outlook is largely the result of higher than average temperatures in the Indian Ocean.

For the October to December period, the chances of above median rainfall range from a little over 60% in the far northeast of SA, to below 40% in the southeast corner of the State (see map). So with climate patterns like the current, about 6 seasons out of 10 are expected to be wetter than average in the the far northeast, whilst about 6 out of 10 would be expected to be DRIER than average in the far southeast.

probability of exceeding median rainfall - click on the map for a larger version of the map

Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During October to December, history shows this influence to be moderate across the eastern half of SA, and weak or very weak across western areas of the State (see background information).

The tropical Indian Ocean is currently warmer than average, whilst the Pacific is showing near normal temperatures. For more detail see the El Niño Wrap-Up. The excess warmth in the Indian Ocean has had the greater influence on the overall pattern of probabilities.

August's value of the Southern Oscillation Index (SOI) was –2, five points below the July value of +3. The approximate SOI for the 30 days ending 13th September was –1.

 

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 16th OCTOBER 2003.

August 2003 rainfall in historical perspective

June to August 2003 rainfall in historical perspective

 

Background Information