|Qld Seasonal Rainfall Outlook: probabilities for August to October 2006, issued 25th July 2006|
Below average falls indicated for north and west Queensland
There is a moderate to strong shift in the odds towards below normal seasonal rainfall across most of northern and western Queensland, the Bureau of Meteorology announced today. In the southeast, the chances are generally close to 50% for accumulating at least median rainfall over August to October.
The pattern of seasonal rainfall odds across Australia is partly a function of raised temperatures in the Pacific, but more strongly related to rapidly increasing Indian Ocean temperatures.
For the August to October period, the chances of above median rainfall are below 40% north of a line that connects the SA/NSW/QLD border region with Rockhampton in Queensland, and with Daly Waters in the NT (see map). In the Northern Goldfields district, the chances drop to about 20%. These probabilities mean that below median falls have a 60 to 80% chance of occurring throughout much of the north and west of the State.
So in years with ocean patterns like the current, about six to eight August to October periods out of 10 are expected to be drier than average in these parts of Queensland, with about two to four out of ten being wetter. However, it should be remembered that it in terms of average conditions, it is a rather dry time of year in northeastern Australia, with heavy rain being uncommon.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During August to October, history shows this effect to be moderately consistent across most of Queensland (see background information).
After falling to −10 in May, the Southern Oscillation Index (SOI) rose slightly in June to a value of −6. The approximate SOI for the 30 days ending 22nd July was −9.
Although the chances of an El Niño have risen somewhat in the past month, continued neutral ENSO conditions is the most likely outcome 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 Climate and Consultancy section in the Bureau's Brisbane Office: (07) 3239 8660.|
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 24th AUGUST 2006