Wild winds are buffeting parts of Victoria, New South Wales, South Australia and Tasmania, with conditions set to worsen in some regions into the night.
Southern parts of South Australia including Adelaide, western areas of Victoria, and the whole of Tasmania were hit by intense and potentially damaging winds throughout the day.
The front was expected to cross southeast New South Wales and the southwest coast of Victoria later on Tuesday afternoon or evening, and could last into early Wednesday.
The worst gusts were expected to be in excess of 120kmh.
Some parts of Melbourne were predicted to suffer through their windiest day of the year, with thunderstorms on the horizon.
— Perrin Brown (@PerrinPezzaBrwn) July 17, 2018
In Victoria, severe thunderstorms may hit Melbourne, Mornington Peninsula, Geelong, Kyneton, Ballarat, Wonthaggi and Bacchus Marsh, the Bureau of Meteorology warned on Tuesday afternoon.
For NSW, severe winds were expected in parts of Illawarra, South Coast, Central Tablelands, Southern Tablelands and Snowy Mountains Forecast Districts.
The danger zones in South Australia were Mount Lofty Ranges, Kangaroo Island, Riverland, Murraylands, Upper South East, Lower South East and parts of Mid North districts, the bureau said.
In Tasmania, damaging northwesterly winds up to 110kmh were possible across the whole of the island.
Earlier in the day, Bureau of Meteorology senior forecaster Michael Efron said Tuesday would be “very windy” and “very chilly”.
“A strong cold front will reach the west of the state during the morning and then rapidly cross the rest of Victoria during the afternoon and evening,” he told AAP.
“Certainly very windy conditions expected. A very chilly day.”
Snow is also expected to fall at heights above 1000m along with “some useful” rain.
The State Emergency Service urged affected residents to move their cars undercover, secure loose items and keep clear of fallen powerlines.