Thousands lose power as winds lash Vic, SA

Some Victorians may be without power until next week after wild winds lashed the state, damaging homes and causing widespread blackouts.

Victoria State Emergency Service received more than 3000 calls for help in 24 hours, with about 490 people reporting damage to their properties and 2300 reporting fallen trees.

Seven houses suffered significant damage including the home of an SES unit controller in Emerald.

"Fortunately for him and his family, nobody was injured," SES chief officer operations Tim Wiebusch told reporters on Friday.

SES crews are still dealing with half of the calls for help, and people are waiting about half an hour for calls to the 132 500 line to be answered.

At the peak of the electricity outages, about 8.30am on Friday, power was cut to almost a quarter of the state, with 520,000 households off the grid.

As of Friday afternoon, 328,000 properties are still without power.

The energy market operator AEMO said the damage to powerlines was severe and warned some customers won't have electricity this weekend or even by early next week.

It is the first weekend Victorians have been allowed to travel freely through the state, with many Melburnians planning to visit regional Victoria for the first time in months.

Some of the hardest hit areas are popular tourist destinations including Apollo Bay, the Dandenongs, and the Mornington Peninsula.

"Victorians travelling this weekend should consider their plans as storms and electricity outages are widespread," AEMO said in a statement.

Emergency Management Commissioner Andrew Crisp said there could be more wild storms in coming days.

"This is a taste, we will see more of this... we could be in this same position again next week," he said.

Bureau of Meteorology senior forecaster Christie Johnson told AAP several locations recorded their strongest wind gusts in a decade or more, including Viewbank (104 km/h), Hopetoun (83 km/h) and Ben Nevis (117 km/h).

In Bass Strait, Hogan Island clocked up wind gusts of 165 km/h, while parts of the Surf Coast recorded October wind speeds not seen in 20 years.

Ms Johnson said the damaging winds were caused by an intense low-pressure system moving across the state, with thunderstorms in the northwest developing at the same time as a storm system over Geelong.

The low-pressure system came with the lowest mean sea level pressure recorded in at least two decades, which resulted in unusually strong winds, she said.

Meanwhile, sections of several metropolitan train lines are still suspended, and there are major delays on a number of V/Line services.

Several vaccination centres were closed because of the storms, while two schools in Frankston and Pakenham were unable to run VCE exams as others proceeded without power.

"Any students who missed their exam due to the storms will be eligible to apply for a derived examination score," a Department of Education and Training spokesperson said.

A severe weather warning for damaging winds is still current in Gippsland as the weather system moves eastwards.

The storms also caused widespread damage in South Australia, leaving more than 30,000 homes and businesses in Adelaide without power.