Seasonal Climate Outlook Message for December 2002 to March 2003

The bottom line

Relief Rain Forecast (Dated 11/12/02)

There has been an improvement in the rainfall outlook for summer. Currently there is around a 40% chance of getting median rainfall during December to February for the eastern half of Australia.

While these rainfall probabilities indicate useful relief rain for much of Queensland (eg. 80% chance of getting at least 95mm at Winton, 120mm at Roma and 200mm at Crow's Nest, Charters Towers, Kingaroy etc), an El Nino pattern still persists in the Pacific Ocean.

Therefore in the shorter term there remains only a low chance of getting those well above average widespread rainfall events needed to break the drought. We will continue to monitor this pattern over the next few months to provide an assessment as to when the El Nino is expected to break.

The 30-50day intra-seasonal oscillation (also know as the MJO) is a band of low atmospheric pressure that originates off the east coast of central Africa. It travels eastward across the Indian Ocean and northern Australia roughly every 30 to 50 days. While it is mainly a tropical phenomenon, it appears to indicate the timing of potential rainfall events (but not indicate rainfall amounts) over central and southern Queensland.

The use of the MJO as a reliable forecast tool is still at the research/experimental stage. The last passage of the MJO occurred in mid November as a fairly inactive event and did not help trigger any widespread rainfall events. It is next expected late in late December/early January. It will be interesting to see if it helps induce some useful widespread rain at that time.

Information from the Bureau of Meteorology www.bom.gov.au also suggests that the development of the northern Australian monsoon season is also unlikely to occur before late December/early January.

As rainfall probabilities and median rainfall levels vary across the Australia, we recommend referring to Australian Rainman for more specific rainfall data for your location. Alternatively contact me through the DPI Call Centre on 13 25 23.

The 30day average of the SOI as of the 11/12 is minus 13. ..