A severe weather warning has been issued for most of Victoria, with heavy rain and damaging winds expected to bring flash flooding.

A deep low pressure system that brought flooding to parts of central Australia and wild weather to South Australia is now moving across the state.

Winds are expected to reach up to 90 kilometres per hour but there’s a chance of 120kph gusts in elevated areas.

Heavy rain may lead to flash flooding in the Mallee, Wimmera and South West districts, with thunderstorms also forecast for the north-west.

The Bureau of Meteorology (BoM) said up to 50 millimetres of rain could fall in some areas.

Severe Weather Warning issued for Wed as a deep low pressure system approaches #Victoria. Details at https://t.co/HLs2UYFQyQ #vicweather pic.twitter.com/jVYejqiPoO

— Bureau of Meteorology, Victoria (@BOM_Vic) December 27, 2016

Damaging winds are forecast for much of the state, including Mildura, Horsham, Warrnambool, Bendigo, Seymour, Maryborough, Ballarat, Geelong and Melbourne.

Dean Stewart from the BoM said Melbourne would get a mixed bag of weather.

“It will be around the middle of the day into the afternoon that we’ll have our strongest winds and we have actually got gale warnings for Port Phillip and Western Port, so some pretty gusty conditions,” he said.

“I think we’ll also get some breaks of sunshine pushing our temperature up to a top of 35 degrees”.

The SES said it had responded to more than a dozen calls for help for fallen trees, mostly in the city’s northern suburbs.

About 4700 homes were without power around Ballarat while 275 were blacked out at Sunshine West.

Murray River campers warned of falling trees

The State Control Centre’s Andrew Murton said it was not a good time of year for dangerous weather.

“With a lot of holidaymakers and people out and about, particularly with the winds and gusts up to 90, 100 kilometres, we certainly ask all the people potentially camping along the Murray to be aware of falling trees, particularly trees down on roads,” he said.

Emergency Management Commissioner Craig Lapsley was worried campers could be caught in flash flooding.

“Stay attuned to the information so you can make a decision about your safety, as it’s going to be a pretty unstable and dynamic couple of days,” he said.

Melbourne sweated through another uncomfortable and humid night, with the mercury at 30 degrees Celisus at 7:30am.

It did not dip below 20C overnight it most suburbs.