|National Seasonal Rainfall Outlook: probabilities for April to June 2007, issued 26th March 2007|
Above-normal June quarter falls favoured in SE Qld & northeast NSW
The national outlook for total June quarter (April to June) rainfall, shows a moderate swing in the odds towards above-normal rainfall in southeast Queensland and northeast New South Wales. However, over most of the country the chances of accumulating at least average rain for the coming three months are close to 50%.
The pattern of seasonal rainfall odds across Australia is a result of recent higher than average temperatures in the equatorial Pacific Ocean and also in parts of the tropical and sub-tropical Indian Ocean. More influence has come from the Indian.
The chances of exceeding the median rainfall for the April to June period are between 60 and 70% in the region bounded by Jervis Bay, Nyngan, Augathella, Bundaberg and the east coast (see map). So in years with ocean patterns like the current, about six June quarters out of ten are wetter than average and four out of ten are drier in these regions with enhanced odds. A small part of the Gascoyne in WA also has increased chances for a wetter than average season.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the June quarter, history shows this effect to be moderately consistent in a band from northwest WA across SA, the far southwest of NSW and over most of Victoria. Moderate consistency is also evident in southeast Queensland, northeast NSW, eastern Tasmania and patches in the NT. Elsewhere the effect is only weakly or very weakly consistent (see background information).
The Southern Oscillation Index (SOI) has been rising recently with values of −7 in January, −3 in February and an approximate 30-day value of +5 as at 21st March.
The 2006/07 El Niño has ended, with central to eastern Pacific temperatures having cooled to near-average. There is an increased chance of a La Niña developing in 2007 - for routine updates and comprehensive discussion on any developments in this regard 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.
|The following climate meteorologists in the National Climate Centre can be contacted about this outlook: Grant Beard on (03) 9669 4527, Blair Trewin on (03) 9669 4623, Lyn Bettio on (03) 9669 4165.|
Regional commentary is available from the Climate Services Centres in the Bureau's Regional Offices:
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 23rd APRIL 2007