Australia's flood-ravaged communities have been dealt a new blow with heavy rain likely to return this year after the Bureau of Meteorology issued a La Nina alert on Tuesday.
Following renewed cooling in the tropical Pacific Ocean, there is now a 70 per cent chance of another La Nina forming in the coming months.
The bureau's climate outlook for the next three months now includes higher than average rainfall for all of Australia except the west, and if La Nina is established a wet summer will follow.
An increased likelihood of flooding
A ‘triple dip’ third consecutive La Nina event would lead to frequent and widespread bursts of heavy rain in eastern Australia, South Australia and the Northern Territory, Weatherzone says.
Weatherzone Senior Meteorologist Brett Dutschke says the weather pattern could spell disaster for those who’ve already been inundated this year.
“Given that eastern and central Australia has had above average rain for the past few months, certainly along the east coast, the soil is fairly saturated,” he told Yahoo News Australia.
“It is the most saturated it has been in decades so we don’t need as much rain as what we have had in order to cause flooding.”
He adds that even infrequent bursts of rain over the next few months could be problematic.
“Even moderate amounts of rain can cause water to just sit on the ground and flow across the ground, rather than soak in,” he explained.
“So if we do go into La Nina again there is an [even greater] increased chance of flooding.”
The @BOM_au has just issued a La Niña ALERT, meaning there is now a 70% chance of La Niña being declared later this year. If it is, this would be the first time on record we have seen 3 consecutive La Niña events coinciding with back-to-back negative IOD years. pic.twitter.com/q9hKMmsD4Z
— Ben Domensino (@Ben_Domensino) August 16, 2022
Records to be broken
It’s been only two months since the bureau announced an end to the last La Nina cycle.
Now widespread areas of Australia are on alert once again.
“Queensland, New South Wales, northern Victoria, the eastern interior of South Australia and eastern parts of the Northern Territory are the most likely to be affected,” Mr Dutschke said.
“They have the greatest chance of exceeding average rainfall in the next few months.”
While even in the absence of a La Nina he says Sydney is set to smash more rainfall records.
“I think even without La Nina, Sydney is highly likely to exceed its previous annual record,” he claimed.
So far more than 1,972mm of rain has fallen over the harbour city in 2022, just 222mm off the 1950 record.
“So I don't think it matters too much whether it is La Nina or not, Sydney only needs to achieve below average rainfall from here on in to achieve that.”
‘It’s not just about the rain’
While a third consecutive La Nina event could be devastating for widespread areas of Australia, Weatherzone warns that it’s “not just about rain".
Mr Dutschke says the weather pattern can have other disastrous impacts.
“A La Nina typically means there will be more clouds [so] less solar generation, it means nights will stay warmer and as we go into the warmer season, it could mean more power usage at night in order to keep buildings cool,” he explained.
“Also [it will be] more humid than it would typically be, and with water sitting on the ground there is an increased chance of the mosquito breeding season being a big one as well.”
“There are significant impacts of going into La Nina again,” he warned.
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