|Vic Seasonal Rainfall Outlook: probabilities for October to December 2003, issued 16th September 2003|
Drier season for parts of southern Victoria
The Bureau's rainfall outlook for the December quarter shows that wetter conditions are favoured in the northeast and west of the country. In contrast, the last three months of the year are more likely to be drier than average in parts of southern Victoria. 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 are between 35 and 40% across southwest Victoria and the region between Melbourne and Wilsons Promontory (see map). So with climate patterns like the current, about 6 seasons out of 10 are expected to be DRIER than average in these parts of the State, with about 4 out of 10 being wetter. In remaining parts of Victoria, the chances of above average falls are between 40 and 55%.
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 Victoria (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
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 (EST) Monday to Friday by contacting the Climate and Consultancy section in the Bureau's Victorian Regional Office: (03) 9669 4949.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 16th OCTOBER 2003.