National Seasonal Rainfall Outlook: probabilities for Summer 2004/2005, issued 19th November 2004

Generally neutral outlook for summer rainfall

The chances of accumulating at least average summer (Dec-Feb) rain are close to 50% for most of the country, the Bureau of Meteorology announced today. The one exception is in an area of northeast Queensland where there is a moderate shift in the odds towards below average rainfall for summer.

probability of exceeding median rainfall - click on the map for a larger version of the map

Within about 100 to 200 km of Townsville in northern Queensland, the chances of above median rainfall for the December to February period are between 35 and 40%. So in years with ocean patterns like the current, about six summers out of ten are expected to be drier than average in this region, with about four out of ten being wetter.

The current pattern of outlook probabilities is mainly due to above average temperatures in the Pacific Ocean.

Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During summer, history shows this influence to be moderately consistent across much of WA and scattered areas in eastern Australia, but generally weakly or very weakly consistent through the centre of the country (see background information).

Progress towards a late-developing El Niño event has slowed over the past two months, with consistent cloud and wind patterns failing to materialize. The central Pacific remains warmer than average and at levels consistent with El Niño, but the Southern Oscillation Index (SOI) was only weakly negative, coming in at –4 for October. The approximate SOI for the 30 days ending 16th November was –5.

For routine updates 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 El Niño 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, Felicity Gamble on (03) 9669 4256, David Jones on (03) 9669 4085
Regional versions of this media release are available: | Qld | NSW | Vic | Tas | SA | WA | NT |

Regional commentary is available from the Climate and Consultancy Sections in the Bureau's Regional Offices:
Queensland -(07) 3239 8669 or (07) 3239 8666
New South Wales -(02) 9296 1522
Victoria -(03) 9669 4949
Tasmania -(03) 6221 2043
South Australia -(08) 8366 2664
Western Australia -(08) 9263 2222
The Northern Territory -(08) 8920 3813



Corresponding temperature outlook

October 2004 rainfall in historical perspective

August to October 2004 rainfall in historical perspective


Background Information