‘Triple La Niña’: Australia may face another summer of flooding rains, US expert warns

Seattle-based McPhaden is in Australia meeting fellow scientists and delivered a public seminar in Sydney this week on conditions in the Pacific and what they could mean for the months ahead.

McPhaden said in April, the Nino 3.4 region of the Pacific was at its coldest since 1950. In May, it was the coldest since 1988.

He said even though the world's oceans were heating up because of global heating, there was enough natural variability to overwhelm that heating for short periods, or in particular regions.

"I don't think anyone wants this to happen," he said.

"We have seen how damaging these flood events are. And it would likely be those same coastal towns up and down the coast of Queensland and New South Wales that will be hit by these events."