|Northern Aust Seasonal Rainfall Outlook: probabilities for Winter 2008, issued 27th May 2008|
Above average winter rainfall favoured for Queensland
The northern Australian outlook for total rainfall over winter (June to August), shows a shift in the odds favouring a wetter than normal season over most of Queensland, with no strong shift in odds to favour wetter or drier conditions over the NT.
The pattern of seasonal rainfall odds across the region is mostly a result of higher than average temperatures in the Indian Ocean.
The chances of exceeding the median rainfall over winter are between 60 and 70% over most of Queensland (see map). So for every ten years with ocean patterns like the current, about six or seven winter periods are expected to be wetter than average in these parts of Queensland, while about three or four are drier. Over all of NT, the chances of exceeding the three-month median rainfall are between 50 and 55%. So the chances of being wetter than normal are about the same as the chances of being drier. It should be noted, however, that this is a relatively dry time of year over much of northern Australia.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During winter, history shows this influence to be moderately consistent across much of Queensland and the NT (see background information).
The 2007/08 La Niña event in the Pacific Basin has decayed to neutral conditions: computer models indicate a continuation of neutral conditions through the forecast period (June to August). The 30-day value of the Southern Oscillation Index (SOI) was −3 as at 24th May. For routine updates and comprehensive discussion on any developments 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 Monday to Friday from 9.00am to 5.00pm local time by contacting the Bureau's Climate Services sections in Queensland and the Northern Territory at the following numbers:
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 26th June 2008