The Bureau of Meteorology [BOM] has declared a La Niña event for the third year in a row, making for a muddy few months ahead.
As part of the event, there would be a high chance of above-average rainfall across the eastern half of Australia during spring and early summer.
La Niña events cause water in the western tropical Pacific Ocean to be warmer and the eastern tropical side of the Pacific Ocean to become cooler than normal, which causes changes in wind, clouds and pressure patterns across the Pacific.
BOM long-range forecasts head Dr Andrew Watkins said the atmospheric change combined with changing ocean temperatures could influence the climate and global weather patterns, which can lead to increased rainfall.
“When this change in the atmosphere combines with changes in ocean temperature, it can influence global weather patterns and climate, including increasing rainfall over large parts of Australia,” he said.
Dr Watkins said that the criteria to create a La Niña weather system have been met and most models have forecast that the event will peak in spring and ease off in summer.
“La Niña is not the only driver influencing this wet outlook,” he said.
“To our west, a significant negative Indian Ocean Dipole [IOD] event is underway.
“We expect the IOD influence will reduce in late spring or early summer.”
The Southern Annular Mode also influenced rainfall and was likely to remain in its current positive phase throughout summer, pushing the weather system south.
Dr Watkins said it would likely increase the chance of rain across New South Wales, eastern Victoria and southern parts of Queensland.
The BOM has encouraged communities to ensure they are up to date with forecasts and any weather warning as they advise catchments are already wet and flood risks will remain in place.
http://www.bom.gov.au/
