|NSW Seasonal Rainfall Outlook: probabilities for Spring 2003, issued 19th August 2003|
NSW rainfall odds neutral for spring
The Bureau's spring rainfall outlook shows a moderate swing towards wetter conditions in southwest WA. However odds are near 50:50 for the remainder of the country with no big swings towards a wetter or drier season across any State or Territory.
For the September to November period in NSW, the chances of above median rainfall are mostly between 45 and 55% (see map). So with climate patterns like the current, about 5 seasons out of 10 are expected to be wetter than average across the State, with about 5 out of 10 being drier.
Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During spring, history shows this influence to be moderate across the state with slightly stronger influences in the south and weaker influences to the north. Users are urged to exercise caution when applying probabilites in areas where the signal is weak (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.
July's value of the Southern Oscillation Index (SOI) was +3, fifteen points above the June value of 12. The approximate SOI for the 30 days ending 16th August 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 (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 16th SEPTEMBER 2003.