Urgent 1000km-long weather warning
The Bureau of Meteorology has issued a severe weather warning stretching 1000km - with wild wind and rain expected to lash large parts of Australia.
Damaging winds of more than 90km/h are expected in some areas affected by the wild weather - which stretches from north of Kempsey in NSW's Mid North Coast to Eden in the South Coast.
Sky News Weather meteorologist Rob Sharpe said much of New South Wales would cop a drenching on Tuesday as commuters head to work, making for "tricky" conditions on the roads.
"People will very much notice that change coming through," he said.
"It's really going to bring some powerful winds. We're worried about wild winds, particularly for that Tuesday morning commute for Sydney and Wollongong."
The cold front drifting north from Tasmania is expected to bring chaotic weather conditions across southern and eastern Australia today.
Bureau of Meteorology forecaster Tom Delamotte described the weather event as "incredible".
The Bureau of Meteorology has issued a severe weather warning for today for large parts of Victoria, including the Melbourne CBD and the alpine region.
Heavy rain, which could cause flash flooding, is forecast across Victoria.
Damaging winds with gusts of 90-100km/h are forecast, and wind gusts across the Alpine peaks may reach 120km/h later today.
Sheep graziers have been warned cold and windy conditions increase the risk of stock losses.
The bureau also warned road users, citing: "The potential for areas of heavy rainfall overnight and Monday morning resulting in reduced visibility and adverse conditions."
As the first cold front passes, a second low-pressure system will drag southerly winds and heavy rain through the southeast of the country this morning.
Forecasters say Victorians can expect a 100 per cent chance of heavy showers today.
Temperatures will be frosty for much of Victoria today, four days after the state shivered through its coldest May day for 19 years.
The mercury in Melbourne will reach just 12C today and 13C on Tuesday. In Ballarat, where it got to a top of 5.7C last Wednesday - the coldest maximum since 2000 - it'll be just 8C today and 9C on Tuesday.
Mr Delamotte said last week's cold front was a "one in 10 to 15-year event", but Sky News chief meteorologist Tom Saunders said the cold southerly airstream to follow this week would be "an incredible start to the season".
New South Wales and Queensland will not be spared the brunt of the storm. After it passes Victoria, it will hit the east coast hard, bringing with it heavy rains and powerful winds.
Newcastle, which has been inundated with rain over the past 24 hours, will get more heavy rain on Tuesday.
Canberra will have one of its coldest mornings of the year on Thursday with a low of -3C. The showers that hit Victoria will pass over the capital tomorrow, where it's expected to rain throughout the day and reach just 10C.
It'll be cold in Adelaide, but South Australians will escape much of the worst of the cold front. Temperatures in the city will reach 14C today and 14C again on Tuesday.
The good news is more snow is expected to accompany the wild weather at slopes including Mount Baw Baw, Falls Creek, Mount Buller and Mount Hotham.
The heavy falls last week led some resorts to open their season a week early but also brought problems.
At Mount Baw Baw, heavy snow knocked down trees and forced the closure of a main road up to the mountain.
On the west coast of Australia, where Perth just experienced its driest May in 55 years, things are about to change.
Mr Sharpe says the "entire west coast" will get significant rain and "cold, wet and windy conditions" on Thursday, Friday and Saturday.