The Bureau of Meteorology has announced the end of the 2023-24 El Niño, with a growing likelihood that La Niña will return by spring. The central equatorial Pacific has returned to neutral conditions, roughly seven months after El Niño began.
El Niño usually results in below-average rainfall across much of eastern Australia, while La Niña brings wetter conditions to northern and eastern regions during the winter-spring period. Notably, August to October marked Australia’s driest three-month period ever recorded by the bureau.
The El Niño-Southern Oscillation (ENSO) is a major climate driver, measuring air pressure differences between Darwin and Tahiti. According to the bureau, international climate models suggest ENSO will likely remain neutral until at least July 2024, but there is a possibility of La Niña forming by spring.
The Bureau of Meteorology forecasts a potential La Niña forming by spring 2024.If La Niña develops later this year, it would be the fourth occurrence in five years, a sequence never recorded before. Other agencies, including the US National Oceanic and Atmospheric Administration, also forecast a high probability of La Niña later in 2024, with predictions as high as 85%.
La Niña typically strengthens easterly equatorial winds, shifting rainfall patterns toward Australia and southeast Asia. Cyclone activity in Australia often increases during La Niña years. Additionally, the Pacific absorbs more warmth than during El Niño years, compounding the effects of climate change.
Global sea surface temperatures have been record-breaking from April 2023 to March 2024, with April 2024 tracking to be warmer than the previous year. The bureau cautions that predictions made in mid-autumn are less accurate, and the unprecedented global ocean conditions may make future ENSO developments less predictable.