|NSW Seasonal Rainfall Outlook: probabilities for July to September 2006, issued 27th June 2006|
50:50 chances for above average September quarter rainfall
The current seasonal rainfall odds do not strongly favour either wetter or drier than average conditions. Therefore, the chances of accumulating at least median rain during the September quarter (July-September) are close to 50% across New South Wales, the Bureau of Meteorology announced today.
The pattern of seasonal rainfall odds across Australia is largely a result of above average temperatures in the Pacific Ocean. Conditions in the Indian Ocean are near normal and have had little influence on this outlook.
For the July to September period, the chances of above median rainfall are between 45 and 50% over NSW (see map). So in years with ocean patterns like the current, about five September quarters out of 10 are expected to be drier than average over the State, with about five out of ten being wetter.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During July to September, history shows this effect to be moderately consistent across large parts of NSW (see background information).
After moderately positive values of +14 and +15 in March and April respectively, the Southern Oscillation Index (SOI) dropped substantially in May to a value of −10. The approximate SOI for the 30 days ending 24th June is −9.
It is likely that neutral ENSO conditions will remain in place for the remainder of 2006. For routine updates and comprehensive discussion on the latest data relating to ENSO, together with details on what the phenomenon is and how it has affected Australia in the past, please 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 NSW Climate Services section in the Bureau's Sydney Office: (02) 9296 1610 or (02) 9296 1525.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 25th JULY 2006