The Australian Bureau of Meteorology says neutral ENSO conditions -- neither El Nino or La Nina -- are currently being observed, but the agency says warming of the tropical Pacific Ocean is likely in the coming months. It warns that climate models that span the next three months have a lower level of accuracy, but says subsurface ocean temperature readings have warmed "substantially" in recent weeks.
The bureau says all models suggest warming of the tropical Pacific Ocean will occur leading into winter (June-August), with some, but not all, models either approaching or exceeding El Nino thresholds by July. "Hence neither neutral nor El Nino states can be discounted for the second half of 2014, while La Nina appears unlikely," it adds.
"A strong burst of westerly wind occurring now over the far western tropical Pacific, may cause further warming of the subsurface in the coming weeks," adds the bureau.
The Indian Ocean Dipole (IOD) typically has little influence on the Australian climate from December to April. "Current model outlooks suggest neutral IOD conditions for late (Southern Hemisphere) autumn into early winter. The risk of a positive IOD event occurring is elevated during El Niño events," says the bureau.