Pro Farmer Editors

Conditions continue to show signs "typical of a developing El Niño event," according to the latest update from the Australian Bureau of Meteorology.

"These indicators are driven by warm conditions in the tropical Pacific Ocean," the agency said in its latest summary. " If these warm conditions persist, as forecast by leading climate models, 2009 will be considered an El Niño year. Pacific Ocean surface temperatures continue to exceed El Niño thresholds. As a result, cloud patterns, Trade winds and rainfall along the equator have all shown signs of responding to the warmer ocean conditions."

Importantly, perhaps, the Australian agency pointed out that the Southern Oscillation Index (SOI) has fallen over the past two weeks, and is now near zero. In their prior update, they pointed out the SOI values had remained in positive territory, noting that persistent negative values are a feature of El Niño events.

"The last month has seen below average rainfall across much of eastern Australia with particularly dry conditions through Queensland," the agency said, noting, "El Niño periods 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."

The most recent value of the Indian Ocean Dipole (IOD), as measured by the Dipole Mode Index (DMI), is near zero. The Bureaus POAMA model suggests the DMI may increase over the coming months, consistent with the developing El Niño event.