Seasonal Climate Outlook - December to February 2010
The Bureau of Meteorology released its rainfall outlook for December to February on 24 November. The outlook reports that across the majority of the State, the odds of the coming season being wetter than normal are the same as the chance of it being drier.
The Bureau issued its latest ENSO Wrap-Up on 25 November. The Bureau reports a ‘maturing’ El Niño event, which is likely to extend into 2010. Temperatures in the central Pacific remain at the highest levels since at least the El Niño event in 2002, and the warm ocean conditions are expected to last into the first quarter of 2010. Satellite observations show increasing cloudiness near the date-line and a shift of the South Pacific’s major rainfall zones toward the northeast of the region. Although slightly higher, Southern Oscillation Index (SOI) remains at levels typical of an El Niño event. Negative SOI values are associated with El Niño events. El Niño events are usually (but not always) associated with below normal rainfall in the second half of the year across large parts of southern and inland eastern Australia.
Despite these conditions, the value of the Indian Ocean Dipole (IOD), as measured by the Dipole Mode Index (DMI) is neutral and is expected to remain neutral over the coming months. A positive IOD is typically associated with decreased rainfall across parts of central and southern Australia.