Hundreds of thousands of Victorians are without power as wild winds and flooding hit the state, while NSW and Queensland are shivering through a cold snap.
Damaging overnight winds up to 120km/h have caused widespread damage across parts of Victoria including Melbourne.
The Victorian SES has had over 3000 call-outs across the state over the past 12 hours, with most for trees down (2577) and building damage (400).
Lilydale and Emerald in the city's outer southeast were among the hardest-hit areas.
The wild weather has left more than 215,000 Victorian customers without power as at 10am on Thursday, and delayed some Melbourne train services.
To the west of the state, Gippsland is on alert for major river flooding after Mt Baw Baw, Mt Tassie and the Thomson-Yarra Divide all recorded rainfall totals over 200mm.
"That water is all going to come down the hills and hit us," Gippsland South MP Danny O'Brien told reporters on Thursday.
The Traralgon Creek at Traralgon is nearing its peak and the Thomson River at Sale is likely to peak on Thursday afternoon.
Mr O'Brien, who is returning to his Sale home to monitor the situation, said a local brigade had already been called out three times for people stuck in cars trying to drive through floodwaters.
"Our emergency services have got enough to do without having to try and deal with these issues that can be avoided," the Nationals MP said.
"If you don't need to be travelling today stay at home, please be very careful on the roads slow down and don't drive through floodwaters."
Victorian SES commander Jackson Bell said he had not seen a weather event like it for some time.
"We've got one part of the state experiencing the significant rain and then we've got another part of the state, particularly metropolitan Melbourne and other parts, experiencing significant wind," he told Nine's Today.
"As you would have seen from the devastation, it will be days to come in the clean up that's for sure."
A severe weather warning for damaging winds remains current for southern parts of Victoria, and northern parts of Tasmania are in a similar boat.
In NSW, the regional NSW towns of Orange in the state's Central West and Oberon in the Central Tablelands have been turned into winter wonderlands.
The cold snap has brought widespread snow in the ranges, with the Perisher Valley receiving a dump of about half a metre.
Sydney is expected to reach only 11C on Thursday as the mercury in some NSW areas dips more than 10 degrees below average for this time of year.
With unseasonably low temperatures in Queensland as well, the Sunshine State's Granite Belt had also expected a rare dusting of snow.
But it has been a no-show thus far over the peaks around Stanthorpe, with current conditions too dry.
