La Nina: Australia on high alert for return of major weather system – this is what the coming months could look like

After weeks of rain, Aussies could be in for months to come later this year after the Bureau of Meteorology issued a La Niña watch for Australia.

The warning comes just a month after the announcement of the end of La Niña’s opposite weather event, El Nino.

The Bureau of Meteorology said that while conditions in the tropical Pacific are currently neutral, there are some signs that a La Niña could form in the Pacific later in 2024.

‘The long-term forecast for June to August shows an increased chance of above-average rainfall across parts of eastern Australia, and parts of Western Australia and South Australia.’

Sky News meteorologist Alison Osborne said the Bureau of Meteorology’s La Niña watch means a La Nina will develop 50 per cent of the time while current conditions are observed.

Ms Osborne explained that cooling ocean temperatures have been recorded over the equatorial Pacific Ocean in recent months.

The Bureau of Meteorology said there are some signs that a La Niña could develop in the Pacific Ocean later in 2024.

The long-term forecast for June to August shows an increased chance of above-average rainfall in parts of Australia, the Bureau of Meteorology said.

The long-term forecast for June to August shows an increased chance of above-average rainfall in parts of Australia, the Bureau of Meteorology said.

Typically, La Niña sees a shift in rainfall patterns towards Southeast Asia and Australia

Typically, La Niña sees a shift in rainfall patterns towards Southeast Asia and Australia

“During a La Nina, these cold ocean temperatures also interact with the warm ocean temperatures on the other side of the Pacific Ocean and this difference helps strengthen the trade winds.”

She said strengthening trade winds over the warmer waters of the western Pacific typically generates more rain-bearing systems for Australia.

La Nina This usually happens every three to five years, but it can also occur over a number of consecutive years.

Australia had a triple La Niña event in 2020/21, 2021/22 and 2022/23.

This was only the third time in history that the event took place in Australia three years in a row.

Typically, La Niña sees a shift in rainfall patterns towards Southeast Asia and Australia and a strengthening of easterly equatorial winds.

This results in increased rainfall over most of Australia and areas south of the tropics with cooler daytime temperatures, more tropical cyclones and an earlier onset of the monsoon season.

What is a La Niña event?

La Niña occurs when equatorial trade winds strengthen, altering ocean surface currents and pulling cooler deep water up from below.

This results in a cooling of the central and eastern tropical Pacific Ocean.

La Niña typically means:

  • Increased rainfall across much of Australia Lower daytime temperatures (south of the tropics)
  • Warmer night temperatures (in the north)
  • Shift in extreme temperatures
  • Reduced frost risk
  • Greater numbers of tropical cyclones
  • Earlier onset of monsoon

Source: Bureau of Meteorology