|Qld Seasonal Rainfall Outlook: probabilities for August to October 2005, issued 14th July 2005|
Drier season more likely for much of Qld
Seasonal rainfall odds released today by the Bureau of Meteorology, indicate an increased likelihood of below median falls over much of Queensland. It should be noted, however, that much of the August to October period is in the dry season in Queensland when heavy rain is uncommon. The pattern of seasonal rainfall odds is mostly a result of continuing above average temperatures in the tropical Pacific Ocean.
For the August to October period, the chances of above median rainfall are between 30 and 40% over most Queensland north and west of a line from Cunnamulla to Charleville to Rockhampton (see map). In north central Queensland the probabilities drop a little below 30%. So in years with ocean patterns like the current, about three or four August to October periods out of ten are expected to be wetter than median over much of Queensland, with about six or seven out of ten being drier.
The chances of accumulating at least median rain during the late winter to mid-spring period (Aug-Oct) are between 40 and 50% across the southeast of the State.
Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During August to October, history shows this influence to be moderately consistent across most of Queensland (see background information).
The Southern Oscillation Index (SOI) rose strongly in June to a value of +3, well above the May value of −15. The approximate SOI for the 30 days ending 11th July was +4.
With the rise in the SOI, and continued neutral cloud and wind patterns across the tropical Pacific, the chances of an El Niño developing in 2005 are slim. Furthermore, the widespread rainfall over eastern Australia in June is consistent with a neutral Pacific as opposed to a developing El Niño. 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 Brisbane Office: (07) 3239 8660.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 16th AUGUST 2005