National Seasonal Rainfall Outlook: probabilities for Spring 2004, issued 17th August 2004

Dry Spring more likely in parts of SA, Vic and NSW

There is a moderate shift in the odds towards below average spring rainfall in central to southeast SA and adjacent parts of western Victoria and NSW, the Bureau of Meteorology announced today.

However, due to the poor or very poor start to the southern growing season (April-November), many places in eastern and southeast Australia, have a less than 20% chance of reaching the total growing seasonal average by the end of November. Along the east coast, the chances drop below 10%. For more information on the recent dry conditions, see the Drought Statement.

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

Across central to southeast SA, northwest Victoria and the far southwest of NSW, the chances of above median rainfall for spring are below 40%, dropping below 35% in central SA. So in years with ocean patterns like the current, about six or seven spring periods out of ten are expected to be drier than average, with about three or four out of ten being wetter.

In the NT, WA, Queensland and remaining parts of southeast Australia, the chances of above average seasonal rainfall are close to 50:50.

The current pattern of outlook probabilities is due to recent temperature patterns in both the Pacific and Indian Oceans.

Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During spring, history shows this influence to be moderately consistent across most of Queensland, NSW, Victoria and the NT, and parts of SA, northern Tasmania, southwest and far northwest WA (see background information).

The Southern Oscillation Index (SOI) has remained significantly negative for the second successive month, with a July value of –7 following the June reading of –14. The approximate SOI for the 30 days ending 14th August was –12. Consistent with the negative SOI, the central Pacific has been warming over the past few months. However, given historical precedent and the current model guidance, the triggering of an El Niño event during the second half of 2004 is less likely than the persistence of neutral conditions. For more detail 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, 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

July 2004 rainfall in historical perspective

May to July 2004 rainfall in historical perspective


Background Information