La Niña system could persist into spring, new forecasts suggest

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Those hoping to put away their umbrellas will soon have to wait a bit longer, as the La Niña pattern could persist into spring, two new US-led forecasts suggest.

The new model was released last week by Columbia University’s International Research Institute for Climate and Society (IRI) and the US Climate Prediction Center (CPC).

Current sea surface temperature anomalies in the Pacific Ocean, showing a distinctive La Niña pattern with cooler than average water in the central and eastern equatorial Pacific Ocean and warmer than average water in the equatorial Pacific Ocean western. (NOAA)

“Based on the latest IRI/CPC model forecast, La Niña has a 62 percent chance of persisting through the Southern Hemisphere winter and a 58 percent chance of occurring in the spring,” Weatherzone said.

If the pattern persists as predicted, the chance of above-average rainfall in parts of Australia would increase during the winter and spring.

The Sydney Harbor Bridge seen through a car windscreen as rain pours down on the city, Monday, February 28, 2022. The state of New South Wales has seen more than 500 flood rescues and 927 requests for assistance in the last 24 hours as record rain continues to fall in the eastern states of Australia. (AP Photo/Mark Baker)
Sydney has had more rainy than dry days this year. (AP Photo/Mark Baker) (AP)
Windsor Bridge was inundated by floodwaters along the Hawkesbury River on March 9, 2022 in Sydney, Australia. (Getty)

It comes after Sydney was confirmed to have had more wet than dry days this year with 94 out of 142 rainfall records.

Two factors are driving the new forecasts.

Average winter-spring precipitation (top) of 13 combined La Niña years, indicating the average precipitation and temperature footprints of La Niña.
Average winter-spring precipitation (top) of 13 combined La Niña years, indicating the average precipitation and temperature footprints of La Niña. (Meteorology Office)

Sea surface temperatures are “near or above La Niña thresholds in late winter, and secondly, a negative Indian Ocean Dipole (IOD) appears to be developing in the coming months.

Cities isolated by floods for the second time this year

“A negative IOD also increases the likelihood of above-average rainfall and cooler-than-average daytime temperatures in Australia,” Weatherzone said.

“In fact, several forecast models suggest we could see a strong negative IOD this winter and spring.”

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