La Nina weather event likely to hit for the third time in a row

Australians can expect another summer of rain and floods as a ‘rare’ weather event is predicted to smash the country.

Australians hoping to avoid another wet spring and summer have been delivered a blow after the United Nations’ weather agency forecast the La Nina weather phenomenon will likely last until at least the end of the year.

The World Meteorological Organisation (WMO) advised on Wednesday that there is a 70 per cent chance that La Niña will continue into September-November 2022 before gradually decreasing to 55 per cent in December-February.

It would be the first “triple-dip” La Nina this century, a weather event spanning three consecutive southern hemisphere summers, after it started in September 2020.

Australians can expect more heavy downpours over spring and summer if La Niña continues. Picture: NCA NewsWire / David Crosling

La Nina weather events drove the heavy downpours, widespread flooding and torrid conditions that were experienced in Australia in the 2020-2021 and 2021-2022 summers.

It involves the large-scale cooling of ocean surface temperatures in the central and eastern equatorial Pacific Ocean, leading to changes in wind pressure and rainfall levels.

La Nina conditions have strengthened in the tropical Pacific after trade winds intensified from mid-July to mid-August.

WMO Secretary-General Professor Petteri Taalas said it was “exceptional” to have three consecutive years with a La Nina event.

“Its cooling influence is temporarily slowing the rise in global temperatures – but it will not halt or reverse the long-term warming trend,” he said in a statement.

“The worsening drought in the Horn of Africa and southern South America bear the hallmarks of La Nina, as does the above average rainfall in South-East Asia and Australasia.

“WMO will continue to provide tailored information to the humanitarian sector and to support sensitive sectors like agriculture, food security, health and disaster risk reduction.”

Recent conditions across the globe have made it more likely that “La Niña will continue. Picture: Monash University Climate Change Communication Research Hub

Australians were already prepared for the prospect of another La Niña after the Bureau of Meteorology (BOM) moved from “La Niña WATCH” to “La Nina ALERT” in August.

It meant there was now around a 70 per cent chance of a La Nina weather event hitting the country this spring.

Australia has only experienced three consecutive La Nina events since records started being kept.

The last instance of it occurring was more than two decades ago from 1998 to 2001.

Of the 18 La Nina events since 1900, including multi-year events, 12 have resulted in floods in some parts of Australia.

People pictured moving products out of shops in Brisbane during the floods in February. Picture: Josh Woning

BOM advised that if another La Nina event becomes established in the Pacific Ocean, “the wet conditions will persist into summer”.

“At the moment the Bureau of Meteorology is on La Niña watch, which means that we‘re more likely to see a La Nina this summer,” BOM meteorologist Laura Boekel said.

“If we do see that La Nina, then we could expect to see a wet summer as well.”

Sky News meteorologist Alison Osborne said La Niña would likely last at least until the beginning of summer.

“It’s looking like a weak one that will probably last until the beginning of summer at the earliest,” she told NCA NewsWire.

“But there’s a lot of divergence as to what it will do after January.”