Wind gusts of up to 100km/hr are threatening homes right across the southern part of the country, after the system made landfall at Perth earlier this week.
The Western Australian capital was battered by heavy winds and raid, with a ceiling coming down on a family overnight, and a power outage at Perth Airport leaving hundreds stranded on the tarmac and in terminals.
Power was restored just after midnight, leaving multiple flights delayed or cancelled.
Across the city, about 35,000 people lost power yesterday, with 10,000 still unable to turn on the lights this morning.
South Australia, Victoria and southern NSW are bracing for impact today.
There have already been winds of more than 110km/hr in some parts of Victoria, with warnings of gusts reaching 130km/hr.
There have also been reports of flooding in the south-east, and severe weather warnings in place across a number of areas, including the Central Highlands and Dandenong regions.
Residents are being warned they will need to take shelter as the system develops.
The weather is expected to ease through mid-morning to the afternoon – before a second one hits this evening.