The Bureau of Meteorology firmed up its guidance for this year for the weather pattern known in Australia to produce wet, windy summers, saying it was now under way after it previously had forecast a high chance.

The warning puts the country’s densely populated east coast on alert when many residents are still rebuilding after floods linked to the most recent La Nina which ran into early 2022.

The weather phenomenon was among factors that would “push Australia’s climate towards a wetter phase and … have shaped our outlook for the coming months that shows more than 80pc chance of above average rainfall for many parts of the eastern half of Australia”, the bureau said in a statement.

Wild weather swings in Australia brought its worst bushfires in a generation in late 2019 and early 2020, followed by two La Nina patterns which swelled rivers beyond their banks and left thousands of flooded homes uninhabitable.