Threat of third straight La Nina summer threatens to flood Brisbane

Experts have warned the devastating La Nina weather pattern could linger for a third straight summer, bringing threats of further flooding.

Queenslanders face the possibility of an unusually wet winter and another summer devastated by heavy rain and flooding, meteorologists warn.

It was initially hoped the climax of the miserable summer would spell the end of La Nina, but the lingering weather system compounded by warmer sea conditions has created the likelihood of prolonged rainfall.

The Bureau of Meteorology said several indicators of La Nina had in fact “increased their strength over the past fortnight” and was now predicting the system to smoother the eastern states until July.

But a senior scientist at the University of New South Wales, Dr Agus Santoso, said the system could linger due to the effects of warmer water in the Indian Ocean.

“This Indian Ocean La Nina, marked by a warmer-than-normal eastern Indian Ocean, could prolong wet conditions for months ahead,” he said.

Experts warn the east coast faces another summer of devastating floods. Picture: Peter Wallis/Getty Images

Sky News chief meteorologist Tom Saunders said there was now a real possibility the weather system could extend to a third consecutive Australian summer, with an increased threat of flooding given catchments were already saturated.

“The indications from global modelling say it should start to slowly weaken over the next couple of months but that’s been the forecast pivot since summer, and that hasn’t happened,” he told The Courier-Mail.

“So I would say it’s certainly not guaranteed La Nina will weaken and indeed it could stick around right through the winter — and if it does make it through the winter, then there’s every chance it’ll continue through the spring and the summer.

“We are facing the possibility of a third consecutive La Nina year.”

Brisbane’s historic and destructive drenching in February which triggered widespread flooding combined with another heavy rain event this week has led to the wettest start to a year in nearly 50 years.

More than 1400 millimetres has drenched the city so far, which is about 300 millimetres above the annual average, and Mr Saunders said there was “most definitely” a threat of more flooding later this year.

“If we were to see a third consecutive La Nina: wet summer, tropical lows, widespread flooding — it would all be possible,” he said.