SOI Remains Negative (Dated 25/09/02)
The 30day average of the SOI as of the 25th of September is -8.50.
If the SOI remains negative through to the end of the month there will be a low (20-40%) chance across central and northern Queensland of above median rainfall for October to December. For southern half of Queensland the probabilities will be marginally higher (30-50%).
According to recent sea temperature reports sourced from the Climate Prediction Centre www.cpc.ncep.noaa.gov in the Unites States and the Bureau of Meteorology www.bom.gov.au an El Nino event is continuing to persist in the Pacific Ocean.
The signs that indicate the continued presence of an El Nino include warmer than normal sea temperatures throughout the central Pacific, above average rainfall over the eastern tropical Pacific and below average rainfall over much of the western Pacific especially Indonesia.
As well, strong westerly wind bursts (rather than the 'normal' south east trade winds) have been recorded along the equator east of the international dateline. Based on previous El Nino's as well as current ocean and atmospheric conditions, it is likely that this pattern will continue through to Autumn 2003.
It will be interesting to see what impact the El Nino will have on Queenslands spring and summer rainfall as each El Nino event is different in regard to rainfall patterns and drought areas.