Heat, rain baffle El Nino predictions in Australia

Record-high temperatures have hit Perth in western Australia, amid recent extreme weather such as storms in a country bracing for the El Nino climate phenomenon.

The capital of Western Australia state recorded on Saturday its first 40 C day since 2022, reaching up to 41.3 C, according to a report by The West Australian newspaper. The sweltering conditions brought emergency bushfires to the city, with hundreds of firefighters battling an out-of-control bushfire on Sunday.

More than 25 bushfires were burning on Sunday in the vast state, with residents in the shires of Gingin and Chittering, about 60 kilometers north of Perth, at risk from the fast-moving blaze, according to fire authorities.

Yet early this year, towns such as Broken Hill in the western part of New South Wales state, on Australia's east coast, had more than half a year's rain in just two days of early January, the biggest deluge in 63 years.

Australians were warned by scientists to brace themselves for a long, hot and very dry summer because of the El Nino effect in the second half of last year.

Between August and October, the predictions seemed to be on track, with record heat waves from Western Australia to the east coast along with bushfires.

Come November, all that started to change with violent storms and floods from Cape York in the far north of Queensland state to New South Wales and Victoria states down south, fueling questions about the much-hyped El Nino effect.

"It's a question a lot of people are trying to seek an answer for," David Karoly, professor emeritus of the School of Geography, Earth and Atmospheric Sciences at the University of Melbourne, said.

Weather conditions in November and January along the NSW and Queensland coasts are not typical for El Nino, which features conditions usually drier and hotter than normal, Karoly said.

"Yes, it's been hot in December but wetter than is typical for El Nino.

"Despite the wet conditions, climate change and global warming has meant that the maximum temperatures have been above normal in southeast Queensland and northern NSW coast, and above average almost everywhere else."

Agus Santoso, adjunct fellow with the Climate Change Research Centre at the University of New South Wales, said: "El Nino is usually associated with hot/dry weather. This was the case in Australia in the run-up to December but then we have had a series of storms and torrential rainfall along the east coast of the country."

Unusual weather

"It is not the type of weather generally associated with El Nino," he said.

"The impact of El Nino in the Southern Hemisphere is more pronounced during winter and spring and is associated with hot and dry condition over Australia. This typically tends to precondition a drier and hotter summer as well, because there would be less moisture on land available for evaporation and precipitation."

El Nino also tends to coincide with the northward displacement of the Roaring Forties winds toward southern parts of Australia, corresponding to the negative phase of the Southern Annular Mode, he said. "This brings dry air from inland into the east coast, not rain."

The Southern Annual Mode refers to the dominant atmospheric variability mode in the Southern Hemisphere that influences climate and weather conditions in Antarctica and countries such as New Zealand and Australia.

"However, recently the Southern Annular Mode has been in a positive state, so there is more moisture coming from the ocean toward the east coast," Santoso said.