Man dead and woman in critical condition after car crushed by tree in stormy weather in Victoria, southern Australia | Victoria

A man is dead and a woman is in critical condition after her car was crushed by a tree that was knocked down by strong winds.

Rescue workers attempted to free the couple in western Victoria's Gellibrand on Wednesday afternoon, but the male driver died at the scene.

The passenger was flown to hospital by helicopter in critical condition.

The operation was one of more than 1,000 emergency calls in several states as severe weather caused devastating damage in South Australia.

“SES volunteers have been working tirelessly with other emergency services and local councils to ensure we can remove the trees from the streets and people's buildings and properties,” Chief Operations Officer Tim Wiebusch told reporters in Melbourne on Wednesday.

Weather conditions are expected to improve starting Wednesday night, but experts warn that winter storms could continue into early spring.

In Victoria, State Emergency Service volunteers have responded to over 1,000 calls for assistance in the last 24 hours, 800 of which were related to fallen trees.

Severe warnings are also in place for parts of Western Australia, New South Wales and Tasmania, where emergency services responded to 44 calls overnight.

Wiebusch called on the population to be patient, as the operations are expected to continue into the night and the coming days.

According to SES, the damage was concentrated in southeast Victoria and parts of Melbourne.

Unusually high tides and dangerous surf are expected to continue along the south-west coast, as well as in Gippsland and Port Phillip Bay, which could lead to flooding in car parks at surf beaches.

In NSW, emergency services reported destructive gusts of over 110 km/h. The Illawarra, the south coast, the Snowy Mountains, the Blue Mountains and parts of Sydney were affected.

By 3pm, SES teams had responded to 535 incidents across the state, with Illawarra and Greater Sydney most affected.

The NSW Rural Fire Service said it had been called to 27 fires across the state.

In the west of the country, the weather continued to be unpredictable and the Western Australian Fire Service issued a “Prepare Now” warning for parts of the south and southwest coast.

In Victoria, wind gusts of 135 km/h were measured at Wilsons Promontory on the southeastern tip of Victoria and gusts of 128 km/h at Mount Buller.

According to Kevin Parkin, chief meteorologist at the Bureau of Meteorology, the situation is expected to temporarily ease on Wednesday evening.

“There is a risk on Monday as a low pressure system moves across Tasmania … which could produce similar gusts to those we are seeing today,” Parkin told reporters.

“These winter storms are here to stay.”

Victoria's two largest electricity providers, Powercor and AusNet, said they were working to restore power to about 15,000 customers.