La Niña has officially ended after a shift in the Pacific Ocean, but meteorologists warn it could return later this year.
The Bureau of Meteorology said the weather situation was finally over on Tuesday, after months of helping to bring heavy rainfall across Australia.
Meteorologists have observed changes in trade winds, sea surface temperatures and subsurface temperatures in the Pacific.
These factors point to a move towards neutral conditions, said the bureau’s long-range forecasting officer, Dr. Andrew Watkins.
A wetter than average season is likely for most of Australia from July to September. As 2021-22 #The girl slowly weakening, a negative Indian Ocean Dipole (IOD) is likely to develop. Find out more in our #Climate and water outlook: https://t.co/rmGKfMfch5 pic.twitter.com/4oOrO395j0
— Bureau of Meteorology, Australia (@BOM_au) June 16, 2022
“But we’re also aware that the patterns suggest we might return to La Niña later in the year, so we’ve moved to the La Niña watch,” Dr Watkins said.
There is about a 50% chance of a La Niña event happening again in 2022.
The switch to La Niña watch does not change the outlook for above-average rainfall for most of Australia over the next few months, with several other climatic factors affecting the country, Dr Watkins said.
Among them is a developing Indian Ocean dipole, which occurs when there are sustained changes in the difference between sea surface temperature for the western and eastern tropical Indian Ocean. .
A negative Indian Ocean Dipole generally brings wetter than normal conditions to central and southern Australia.
“We are also seeing quite warm temperatures in the oceans around northern Australia and off Western Australia,” Dr Watkins said.
These warmer temperatures also tend to bring wetter than normal conditions to much of Australia.
About half of the patterns studied by the bureau suggest a potential return to La Niña in the spring, and back-to-back La Niña is also not uncommon, Dr. Watkins said.
“We’ve actually been getting them about half the time since 1900,” he said.
“A three-year La Niña is less common, and we’ve only seen this three times since the middle of the last century.”