Australia’s Bureau of Meteorology has issued a warning regarding a potential “La Nia” event.

The Australian Bureau of Meteorology has issued a “La Niña watch” following observations of potential changes in the tropical Pacific Ocean.

According to the Bureau of Meteorology, the current conditions in the Pacific are neutral. However, according to the weather agency’s announcement on May 14, there are signs that La Nia could emerge in the Pacific Ocean later in 2024.

After observing the gradual cooling of sea surface temperatures in the central Pacific since December 2023, the bureau has now shifted its focus to monitoring La Niña conditions. According to experts, a La Niña event has developed approximately 50 percent of the time when these criteria have been met in the past.

The El Niño-Southern Oscillation cycle is a pattern of climate fluctuations in the Pacific that goes back and forth between a warmer phase known as El Niño and a cooler phase known as La Niña.

Located in the central and eastern tropical Pacific Ocean, the change in temperatures has far-reaching effects across the globe. It influences wind, temperature, and rainfall patterns, as well as the intensity of hurricane seasons and the distribution of fish in the seas.

Weather patterns can differ across different regions, but El Niño phases generally lead to increased global temperatures, increasing the likelihood of setting new records for warm years. Despite the cooling La Niña phase, climate change has still caused numerous years in recent history to break heat records.

During the past year, from 2023 to 2024, we have experienced an exceptionally intense El Niño phase. As a physicist would explain, the movement and extension of the Pacific jet stream towards the south due to warmer waters results in the arrival of drier and warmer weather in the northern regions of the US and Canada, while the southern states experience increased rainfall. In Australia, El Niño usually leads to increased temperatures and decreased rainfall in the eastern and northern regions of the country.

Before this, the planet experienced an unusual triple-dip La Niña that lasted from 2020–2023. In the La Niña phase, we observe the inverse of El Niño. Similar to a physicist, the cold waters in the Pacific cause the jet stream to shift northward. As a result, the southern US experiences drier weather, while the Pacific Northwest and Canada see wetter and colder conditions.

Australia is keeping a close eye on the potential resurgence of La Niña, as it was associated with significant flooding in eastern Australia during 2021 and 2022.

Other forecasters are also predicting the potential return of La Niña later this year, not just the Australian Bureau of Meteorology. According to the May forecast from the US National Weather Service’s Climate Prediction Center, there is a 49 percent probability of La Niña developing between June and August. This likelihood increases to 69 percent from July to September. According to the Japanese weather agency, there is a 60 percent probability of La Niña conditions developing during boreal autumn (September to November).