Seasonal Climate Outlook - March - May 2010
The Bureau of Meteorology released its rainfall outlook for March to May on 24 February. The outlook reports a neutral chance overall for total rainfall across south-east Australia being wetter or drier than an average season. For Victoria, the odds of exceeding the median rainfall during autumn are between 45 and 55%.
The Bureau issued its latest ENSO Wrap-Up on 17 February 2010. The Bureau reports conditions suggesting the gradual easing of El Niño conditions. The Bureau reports that recent rainfall patterns over Australia reflect conditions typical of past El Niño breakdowns.
However, the deterioration of El Niño conditions may be slowed by a recent weakening of the trade winds. Sea surface temperatures have eased slightly towards their mean conditions, though still remain at levels typical of an El Niño event. There has been a sharp drop in the Southern Oscillation Index over the past fortnight; however, the Bureau attributes this to a tropical cyclone near Tahiti and the decreased trade winds, rather than any renewal of El Niño conditions.
Leading climate models continue to suggest tropical ocean temperatures may gradually ease towards more average conditions in coming months, but are likely to remain above El Niño thresholds into the southern autumn. The models surveyed do not predict a reinvigoration of El Niño conditions during 2010.