|National Seasonal Rainfall Outlook: probabilities for April to June 2004, issued 17th March 2004|
Mixed June quarter rainfall odds in the east and south
The Bureau's seasonal rainfall outlook for the June quarter shows a strongly varied pattern in the odds over southern and eastern Australia. A drier than average season is more likely in SA, much of Victoria, the far southwest of NSW and Tasmania, while a wetter than average season is more likely in southeast Queensland and the northeast quarter of NSW. This outlook pattern is a result of the combined effects of above average temperatures in both the Pacific and Indian Oceans.
For the April to June period, the chances of above median rainfall are below 40% in a band extending from northwest SA across southwest NSW and Victoria (except East Gippsland) to Tasmania (see map). The probabilities drop below 30% in central SA. This means that BELOW median falls have a 60 to 75% chance of occurring across this broad region. So with climate patterns like the current, about 7 seasons out of 10 are expected to be drier than average in these parts, with about 3 out of 10 being wetter.
Conversely, the chances of above median falls are generally in the 60 to 65% range in the northeast quarter of NSW and southeast Queensland. So with climate patterns like the current, about 6 seasons out of 10 are expected to be wetter than average in these areas, with about 4 out of 10 being drier.
Across WA, the NT and the remainder of Queensland, the chances of a wetter than average June quarter are mainly between 40 and 55%.
Outlook confidence is related to the influence of Pacific and Indian Ocean temperatures on seasonal rainfall. During the June quarter, history shows this influence to be moderately consistent across most of the areas with the large probability shifts, as well as over much of central WA, parts of the northern NT and north Queensland (see background information).
Both the Indian and tropical Pacific Oceans remain warmer than average. For more detail see the the El Niño Wrap-Up.
The Southern Oscillation Index (SOI) has shown strong month-to-month variations recently, in association with active and inactive phases of the northern Australian monsoon. February's value was +9 following the 12 in January and +10 in December. The approximate SOI for the 30 days ending 14th March was +4.
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, Neil Plummer on (03) 9669 4714, Felicity Gamble on (03) 9669 4256|
|Regional versions of this media release are available: | Qld
Regional commentary is available from the Climate and Consultancy Sections in the Bureau's Regional Offices:
THE NEXT ISSUE OF THE SEASONAL OUTLOOK IS EXPECTED BY 19th APRIL 2004.