Seasonal Climate Outlook March - May 2009
The rainfall outlook for the period March to May was released by the Bureau of Meteorology on 20 February 2009.
The outlook shows no strong bias towards either wetter or drier conditions for Victoria. The outlook indicates that the chances of exceeding the median rainfall across Victoria are between 45% and 55% across most of the state, with between 40% and 50% in the south and between 55% and 60% in the north. This means that the chances of being wetter than normal are about the same as the chances of being drier.
The Bureau’s latest ENSO Wrap-Up was issued on 18 February 2009. The slight warming of the equatorial Pacific Ocean has not continued into February. Sea surface temperatures in the far eastern Pacific remain neutral. Trade winds are now stronger than normal in the western half of the basin. The Southern Oscillation Index shows a stronger positive value, with a 30-day (February 16) value of +14. Below the surface, the western and eastern areas of the basin have warmed over the past three weeks, and temperatures in the central Pacific have cooled slightly.
Model outlooks suggest that the cooler sea surface conditions in the Pacific may persist only briefly into autumn 2009. The most likely scenario is for the central and eastern Pacific to warm further over the coming months and to remain neutral. The Indian Ocean Dipole is neutral, as is typical for this time of year, It will be monitored in autumn for any signs of an emerging event.