Seasonal Climate Outlook - August 2011 to October 2011
The Bureau of Meteorology released its rainfall outlook for August to October 2011 on 21 July. The outlook reports that the odds favour a drier than normal season over most of South-East Australia including Western Victoria. The outlook is based on the recent Pacific and Indian Ocean temperature patterns. The outlook factors in the decline of La Niña conditions across the Pacific during the previous season, as well as the persistence of above average temperatures over key parts of the Indian Ocean.
The Bureau’s final ENSO Wrap-Up for July was issued on 20 July. It reports that neutral ENSO conditions persist in the tropical Pacific Ocean, with most atmospheric and oceanic indicators at near normal levels. The majority of international climate models forecast neutral conditions continuing for the remainder of winter and spring.
The influence of the Indian Ocean Dipole (IOD) on Australian rainfall is currently neutral. However, forecasts by the Bureau’s POAMA model suggest there remains a chance of a positive IOD event forming during late winter. Positive IOD events in the past have been associated with drier conditions over South-East Australia during the winter and spring months.