Australia has been put on La Niña watch by the Bureau of Meteorology, indicating a potential shift towards cooler and wetter conditions later this year.
The bureau reports a 50% chance of La Niña forming, with tropical Pacific sea surface temperatures steadily cooling since December. However, the bureau cautioned that the recent record-high global sea temperatures could make predictions less reliable.
The country experienced a rare “triple dip” La Niña from 2020 to 2022 before shifting to the drier El Niño phase last summer.
The US National Oceanic and Atmospheric Administration recently estimated a 69% chance of La Niña developing between July and September.
Bureau climate manager Dr. Karl Braganza emphasized that their long-range forecasts are not solely dependent on the El Niño Southern Oscillation (ENSO) cycle.
The current forecast for June to August indicates an increased likelihood of above-average rainfall in parts of eastern, Western, and South Australia.
For most of eastern Australia, including Queensland, New South Wales, Victoria, and Tasmania, the chances of above or below median rainfall are roughly equal. Additionally, temperatures across the country are expected to be warmer than usual.
Three out of seven climate models, including the bureau’s own, suggest the Pacific might enter La Niña territory by September.
Meanwhile, the Indian Ocean Dipole (IOD), another climate factor influencing Australia’s weather, had been moving toward a positive phase, typically associated with less rainfall and higher temperatures.
However, this development may have stalled, and the latest forecasts predict a weaker event. The bureau noted that forecasting the IOD beyond autumn is historically less accurate.