|NSW Seasonal Rainfall Outlook: probabilities for October to December 2005, issued 15th September 2005|
Odds 50:50 for a wetter than average season in NSW
Although parts of Queensland and Victoria have increased chances of below average December quarter (October to December) rainfall, the odds for a wetter than average season are close to 50:50 over NSW, the Bureau of Meteorology announced today.
For the October to December period, the chances of above median rainfall are mostly between 45 and 50% across NSW (see map). So in years with ocean patterns like the current, about five December quarters out of ten are expected to be wetter than the median over the State, with about five 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 western half of NSW, but generally only weakly consistent in the east (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 (EST) Monday to Friday by contacting the Climate and Consultancy section in the Bureau's Sydney Office: (02) 9296 1522.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 18th OCTOBER 2005