La Niña is over in Australia, but there's a chance it will be back soon, according to the BOM. Pic: ABC Open contributor Daniel Marshall
22 June 22
La Niña, the weather pattern that has lashed Australia with record rain and floods for months, has finally ended, according to the Bureau of Meteorology (BOM).
But some models suggest La Niña may re-form in the southern hemisphere during spring for the third consecutive time.
"As a result, the bureau's ENSO outlook status has moved to La Niña watch ," the BOM reported on Tuesday in its climate driver update.
"La Niña watch means there is about a 50 per cent chance of La Niña forming later in 2022.
"This is approximately double the normal likelihood."The BOM's head of long-range forecasting, Andrew Watkins, said a La Niña watch did not change the outlook of above average rainfall for much of the country over the next few months.
"The bureau's long-range outlook remains wetter than average, consistent with model outlooks from other global forecast centres, reflecting a range of climate drivers including a developing negative Indian Ocean Dipole (IOD) and warmer-than-average waters around Australia," Dr Watkins said.
"Sea surface temperatures are currently warmer than average for much of the Australian coastline, particularly to 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 happened three times before – in 1954-57, 1973-76 and 1998-2001 – according ARC Centre of Excellence for Climate Extremes climatologist Zoe Gillett.
"A third consecutive La Niña and could increase the chances of rain for an already saturated east coast," she said.
This most recent La Niña has been in place since November 2021.
Since then, eastern Australia has seen rain and flood records smashed, with Sydney experiencing its wettest year to date and its 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 was associated with record floods that hit northern New South Wales and southern Queensland in late February and early March this year.
Fifty locations in south-eastern Queensland and north-east NSW recorded more than a metre of rain in the last week of February.
Large parts of eastern and western Australia recorded above-average rainfall this year, with parts of the NSW coast and parts of the Gold Coast Hinterland recording their wettest autumns on record.
- AUTHOR: BEN DEACON
- SOURCE: ABC WEATHER