|National Seasonal Rainfall Outlook: probabilities for November 2008 to January 2009, issued 28th October 2008|
Wetter than normal conditions favoured in the north and west
The national outlook for rainfall over the November to January period shows a moderate shift in the odds favouring wetter than normal conditions over most of northern and western Australia.
The pattern of seasonal rainfall odds across Australia is mainly a result of continued warmth in the central and southeastern Indian Ocean, especially off the west coast of WA.
The chance of exceeding median rainfall over Australia for the November to January period is between 60 and 70% for most of the NT, northern and western Queensland, the Kimberley and adjacent northern interior of WA, and the Gascoyne and southwest districts of WA (see map). The odds rise to 70 to 75% in a few small areas over the Kimberley and northern NT. This means that for every ten years with ocean patterns like the current, about six or seven years are expected to be wetter than average in these regions, while about three or four years are expected to be drier.
Across the rest of the country, the chance of exceeding the median rainfall for the November to January period is between 40 and 60%, meaning that above average falls are about as equally likely as below average falls in these regions.
Outlook confidence is related to how consistently the Pacific and Indian Oceans affect Australian rainfall. During the November to January period, history shows this effect to be moderately consistent across much of Tasmania, NSW, Queensland and the NT, but generally weakly consistent elsewhere (see background information).
The tropical Pacific Ocean remains ENSO-neutral. Sea surface temperatures across most of the equatorial Pacific are near normal, however, sub-surface temperatures have recently cooled. The Southern Oscillation Index (SOI) is currently at +14 for the 30 days ending 25 October. Computer models indicate that neutral conditions are likely to continue for the rest of spring and summer. 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.
|The following climate meteorologists in the National Climate Centre can be contacted about this outlook: David Jones on (03) 9669 4085, Blair Trewin on (03) 9669 4623, Robyn Gardiner on (03) 9669 4671,|
Regional commentary is available from the Climate Services Sections in the Bureau's Regional Offices:
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 26th November 2008