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

Generally neutral odds for NT seasonal rainfall

The Bureau's rainfall outlook for the December quarter shows that wetter conditions are favoured in the northeast and west of the country, whilst a drier than average season is favoured in the far southeast. 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 across the Northern Territory are mostly between 55 and 60% (see map). The chances exceed 60% in a few small patches and along the border with Queensland. So with climate patterns like the current, about 5 or 6 seasons out of 10 are expected to be wetter than average over most of the NT, with about 4 or 5 out of 10 being drier.

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 most of the Northern Territory, although it is weak or very weak in the area around the WA/NT/SA border (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 Darwin Office: (08) 8920 3813.
 

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