La Niña, the weather phenomenon that has plagued Australia with record rains and floods for months, has finally come to an end, according to the Bureau of Meteorology (BOM).
- Climate scientist says third straight La Niña could increase chance of rain for ‘already saturated’ east coast
- A triple La Niña has only happened three times before, most recently in 1998-2001
- La Niña was associated with devastating floods in NSW and Queensland earlier this year
But some models suggest La Niña could re-form in the Southern Hemisphere in the spring for the third time in a row.
“As a result, the office’s ENSO outlook status has changed to a La Niña watch,” the BOM reported in its Climate Factors Update on Tuesday.
“The La Niña watch means that there is about a 50% chance that La Niña will form later in 2022.
“That’s about double the normal probability.”
BOM long-range forecasting officer Andrew Watkins said a La Niña watch did not change the outlook for above-average rainfall for much of the country over the next few months.
“The office’s long-term outlook remains wetter than average, in line with model outlooks from other global forecast centers, reflecting a range of climate factors including a developing Indian Ocean Negative Dipole (IOD) and warmer than average waters around Australia,” said Dr Watkins.
“Sea surface temperatures are currently warmer than average across much of Australia’s coastline, particularly in the north and west.
“This pattern is likely to increase the chance of above-average winter-spring rainfall for Australia.”
A triple La Niña has only occurred three times before – in 1954-57, 1973-76 and 1998-2001 – according to Zoe Gillett, a climatologist at the ARC’s Center of Excellence for Climate Extremes.
“A third consecutive La Niña and could increase the chance of rain for an already saturated east coast,” she said.
This latest La Niña has been in place since November 2021.
Since then, eastern Australia has seen its rain and flood records plummet, with Sydney experiencing its wettest year to date and wettest autumn on record.
“November 2021 was the wettest November in 122 years for New South Wales and Australia as a whole,” Dr Gillett said.
La Niña has been associated with record flooding which hit northern New South Wales and southern Queensland in late February and early March this year.
Fifty locations in southeast Queensland and northeast New South Wales recorded more than a meter of rain in the last week of February.
Large parts of eastern and western Australia have seen above-average rainfall this year, with parts of the NSW coast and parts of the Gold Coast hinterland recording their falls the wettest on record.