Despite currently neutral El Niño–Southern Oscillation levels. the possibility of a weak La Niña in 2016 remains, states Australia's Bureau of Meteorology. It reports that in the Indian Ocean, a negative Indian Ocean Dipole (IOD) continues, but has weakened in recent weeks. The current event peaked in July as the strongest negative IOD event in at least 50 years of record.
Climate models indicate the negative IOD will continue to steadily weaken over the southern hemisphere spring. This means its influence on Australian rainfall may lessen in the coming months. Rainfall has been well above average for large parts of Australia since May 2016—which is a typical rainfall pattern observed during negative IOD events. During negative IOD events, southern Australia typically experiences above average winter and spring rainfall and cooler than average daytime temperatures.
In the Pacific Ocean, only two of eight international climate models monitored by the Bureau indicate La Niña is likely to develop during the fall in the northern hemisphere, with two more indicating a possible late-forming event in winter. The remaining models suggest neutral or near-La Niña conditions. A La Niña WATCH remains, but if La Niña does develop it is likely be weak.