The Australian Bureau of Meteorology says the retreat from El Nino thresholds over the past several weeks is "highly unusual" as September-October is typically the time when developing ENSO events consolidate and mature. The bureau says while some chances of El Nino remain, climate models suggest sea surface temperatures in the tropical Pacific Ocean will likely be warmer than usual but stay within the neutral range.
The bureau says this year has seen a positive Indian Ocean Dipole (IOD), which partly explains the unusually dry conditions experienced over much of Australia in recent months. "Outlooks from the bureau's climate model indicate the IOD is likely to return to neutral values over the next month. A positive IOD is typically associated with decreased winter and spring rainfall over parts of southern, central and northern Australia, but declines in both value and influence with the onset of the Australian monsoon at the start of summer," it states.