Seasonal Climate Outlook August - October 2007
The latest Seasonal Outlook issued by the Bureau of Meteorology on 24 July reports no strong swings towards either above-normal or below-normal rainfall in Victoria over the next three months. The chance of accumulating at least average rainfall is 40% in the west increasing to 55% in the east.
The chances for a warmer than average season across Victoria is between 65 and 70%.
The Bureau issued the latest ENSO Wrap-Up on 1 August. The past three months have seen El Niño Southern Oscillation indicators fluctuate without any consistent trend being apparent. Overall, there was a slight cooling of the ocean from June to July and a decrease in the SOI to -5.
A period of consistently stronger than average Trade Winds, positive SOI values and further cooling of the ocean is required for a La Niña to develop in 2007. The latest runs from major international computer models continue to indicate a moderate chance of this occurring, but not as emphatically as a few months ago.
The chance of a La Niña occurring is about 50:50, however if neutral conditions persist it is likely that even if a La Niña fails to eventuate, conditions are expected to still be wetter than average across eastern Australia.