There is a 50% chance of an El Nino developing this autumn or winter in the southern hemisphere, the Bureau of Meteorology says.

Three out of eight climate models suggest the weather event may occur by the middle of the year.

“Tropical Pacific sea surface temperatures have cooled slightly in the past fortnight, but remain warmer than average,” the bureau says.

“Importantly, in the central to western Pacific, warmer than average subsurface waters persist. This is often a precursor to El Nino events.”

The bureau last November predicted a 70% likelihood of an El Nino forming. It will provide another forecast next week.