Hundreds of Melburnians have been left without power as the squalls damage power lines while an inbound flight from Los Angeles was diverted to Sydney.

Four hundred inner-city homes are without power while over 700 in the east of the state are affected.

Severe weather warnings have been issued for most of Victoria, with heavy rain and destructive winds predicted to reach speeds of up to 130 kilometres in some parts of the state.   

If you are planning a skiing trip to the state's Alpine region, tread with caution.

The Bureau of Meteorology is predicting winds averaging 80 to 90km/h with peak gusts of up to 130 km/h expected to lash the area on Saturday evening and continue well into early hours of Sunday morning. 

Bureau of Meteorology senior forecaster Stuart Coombs said the wild northerly winds were caused by an extremely deep low pressure system moving in from Tasmania.  

"We're predicting the worst winds of the year so far," Mr Coombs said. "We will see damaging winds right across the state, in some parts they may be so strong they could potentially dislodge or bring down trees."

He said areas expected to be the worst impacted include Stawell, Hamilton, Kyneton, Ballarat, Geelong, Melbourne, Wonthaggi, Bacchus Marsh and Falls Creek, with steady winds of 60 to 70 km/h on Saturday. 

Elevated areas like the Dandenong Ranges, Kinglake and Mount Macedon are also expected to feel the wrath of the wild weather with gusts of wind reaching up to 80km/h.

"The weather should be fairly moderate as dawn approaches but then winds will start to strengthen by mid morning and continue to pick up pace into the afternoon," he said.

The fiercest winds are predicted between 11am and 3pm on Saturday. 

The state's north-east will also be hit, with winds between 90 and 109km/h an hour predicted.

"We often see wild weather events like this as we move into spring," he said. "But it's been a very calm winter so many people may be surprised by the extreme conditions over the weekend."

Healesville Sanctuary announced on Saturday that it would close for the day due to the threat of high winds.

In a statement, it said the triage centre would remain open as local native wildlife could be hit by the damaging winds.

Knox's Leisureworks has cancelled swimming classes due to an outage caused by power line being down in Boronia. Crews are currently at the scene.

Mr Coombs urged Victorians to take precautions by preparing their homes and securing loose objects.

"Driving conditions will also be windy and wet so we'd urge people to be take extra caution on the roads," he said. 

But there's light, somewhere over the rainbow, with the windy weather bringing unseasonably warm weather.

A top of 18 degrees is forecast for Melbourne on Saturday, well above average for July, but sadly the winds mean it won't feel as warm.

Horsham is expected to reach a sunny 20 degrees on Saturday while Mildura will hit 27 degrees.  

The State Emergency Service has issued a warning for people living in affected areas to move vehicles under cover or away from trees, secure or put away loose items around your house, yard and balcony, keep clear of fallen power lines and ensure pets outdoors are safe.