National Seasonal Rainfall Outlook: probabilities for February to April 2004, issued 15th January 2004

Neutral seasonal rainfall odds

The Bureau's seasonal rainfall outlook for late summer to mid-autumn shows no strong swings in the odds towards wetter or drier conditions. The chances of above average seasonal falls are generally close to a neutral 50%. This outlook is due to the fact that Pacific and Indian Ocean temperatures have a varying influence on Australian rainfall during summer and autumn.

For the February to April period, the chances of above median rainfall are between 40 and 55% across all States and Territories, except for a small patch in north-central Queensland where the chances are slightly less than 40% (see map). So with climate patterns like the current, about 5 seasons out of 10 are expected to be wetter than average over Australia, with about 5 out of 10 being drier.

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

Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During the February to April period, history shows this influence to be moderately consistent through the northern halves of both Queensland and the NT, most of WA, the far west of SA and southeast NSW. Elsewhere the influence is only weakly or very weakly consistent (see background information).

The tropical Pacific Ocean cooled during December, but there was little change in tropical Indian Ocean temperatures. For more detail see the El Niño Wrap-Up. The temperature patterns in the Indian and Pacific Oceans are not extreme enough to produce large swings in the outlook probabilities.

December's value of the Southern Oscillation Index (SOI) was +10, a strong rise from the –3 recorded in November. The rise in the SOI was in part caused by below average air pressure over northern Australia associated with a strong onset to the monsoon. The approximate SOI for the 30 days ending 12th January was +2.


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 4603, David Jones on (03) 9669 4085, Felicity Gamble on (03) 9669 4256.
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

December 2003 rainfall in historical perspective

October to December 2003 rainfall in historical perspective


Background Information