Victorians are advised to have their brolly at the ready with a deluge of rain forecast for the morning commute.

A cold front is expected to pass over the state early on Wednesday bringing heavy rain, possible flash flooding, thunderstorms and wild winds.

Melbourne could see up to 20mm of rain while northern Victoria is expected cop up to 45mm, the Bureau of Meteorology warns.

“We’re expecting cloudy skies with rain right across the state,” senior forecaster Dean Stewart said.

“Because it’s going to come down quickly there is the potential for flash flooding.”

Damaging winds of up to 70 km/h are forecast with possible peak gusts of about 100 km/h, while gusts in central Victoria and the alps could reach 120km/h.

A severe weather warning has been issued for almost all of Victoria, though conditions are expected to ease from the afternoon.