The declaration by the Bureau of Meteorology of a La Niña in the Pacific Ocean has potentially serious implications for the Goulburn Valley.
The bureau’s three-month climate outlook shows a high chance of above-average rainfall for most of the eastern half of the Australian mainland and eastern Tasmania.
According to the bureau, that means communities in eastern Australia should be prepared for above-average rainfall over spring and early summer.
In the Goulburn Valley, which is essentially a huge flood plain wedged between the Murray and Goulburn rivers and the Great Dividing Range, that has implications when many of the water courses are already high, many of the dams are almost full and with above-average rainfall predicted.
Head of long-range forecasts at the bureau Andrew Watkins said the La Niña event was likely to be weak to moderate in strength and expected to peak during spring and ease during summer.
"La Niña is not the only driver influencing this wet outlook,” Dr Watkins said.
“To our west, a significant negative Indian Ocean Dipole event is under way.
“The Southern Annular Mode is also in a positive phase, and likely to remain positive into summer. Positive SAM during summer pushes weather systems south, which increases the chance of rain in NSW, eastern Victoria and southern parts of Queensland.”
Dr Watkins said the combination of those climate influences indicated a wetter phase for the coming months, with a more than 80 per cent chance of above-average rainfall in many parts of eastern Australia.
The bureau would not be interviewed on specific forecasts for the Goulburn Valley, but the Victoria State Emergency Service is warning residents to prepare for flooding.
VICSES said 2021 was a cold and wet spring with several major storms, and similar conditions were expected this year.
“The last two years have been two of the busiest years in our organisation’s history, and our SES volunteers have continued to answer the call and I thank each and every one of them for that as they once again prepare for a busy season ahead,” VICSES chief officer Tim Wiebusch said.
“VICSES volunteers are highly trained and will be ready and prepared to respond to requests for assistance to flood and storm events as required; however, we are asking communities to also prepare.
“Make sure you stay informed, and listen to the advice of emergency services as warnings are issued.”