Wild winds and tidal surges are bringing dangerous weather to Australia’s south-east, as a cold front sweeps across several states.

Wednesday is expected to be the coldest day of the current spell in Victoria and southern NSW, while eastern parts of Australia will bear the brunt on Thursday.

It follows a wintry burst that brought dust storms, rain and damaging winds to South Australia on Monday and Tuesday.

Sky News meteorologist Marina Neuman said the “entire coastline” in Australia’s south-east will be under threat.

“We are seeing very high tides right now, as well as damaging surf warnings and coastal hazard warnings from those strong wind gusts,” Neuman said on Wednesday.

There have been widespread wind gusts of more than 100km/h across SA this week, as well as more than 30 millimetres of rain in many places.

A storm surge across Gulf St Vincent peaked on Tuesday afternoon, with warnings of sea levels up to 3.8 metres – prompting reports of businesses sandbagging in Adelaide’s busy Glenelg beach area.

The State Emergency Service warned people to avoid coastal areas,  secure boat moorings for boats and be prepared for possible coastal flooding.

“We want people to keep themselves safe during this extreme weather event,’’ chief of staff Derren Halleday said.

“If a jetty is closed, please avoid it. Some jetties are still undergoing repairs following a similar extreme weather event we experienced in late March. Abnormally high tides are also forecast for later this afternoon and into the evening.’’

Among the worst affected was the jetty at Normanville, which was already storm damaged. Part of it collapsed into the sea on Tuesday.

On Wednesday, the weather bureau issued a warning for abnormally high tides along most of the Victorian coastline.

Affected locations included Geelong, Melbourne, Portland, Port Fairy, Inverloch, Port Albert, Silverleaves, Barwon Heads, Frankston and Lakes Entrance.

Conditions were expected to ease later in the day.

Source: Bureau of Meteorology

Further north, the Bureau of Meteorology has warned of hazardous surf along the NSW Hunter and Sydney coasts on Thursday.

Forecaster Weatherzone said the powerful cold front would bring strong west-to-south-west winds and showers across much of south-eastern Australia, making it feel up to seven degrees colder than actual temperature.

“Chilly mornings will take hold into the weekend as this polar airmass slowly dissipates and high pressure brings clearer skies and lighter winds,” it said.

Melbourne is predicted to reach a top of just 11 degrees on Wednesday – and will feel no warmer than about six or seven degrees.

Adelaide had a maximum of 13.6 degrees on Tuesday, but was expecting about 15 degrees on Wednesday and Thursday.

“However, the wind chill will make it feel no warmer than about 12-13 degrees,” Weatherzone said.

It will also be cold in Hobart, which was forecast to reach no more than 10 degrees on Wednesday, with showers and possible thunderstorms.

In Canberra, the mercury was tipped to get to eight degrees – “but feeling no warmer than two-three degrees throughout most of the day”.

“Conditions improve on Thursday with a maximum of 10 degrees (feeling about four degrees colder with the wind chill) and periods of sunshine,” Weatherzone said.

Sydney will enjoy a sunny day and a top of 18 on Wednesday, with 16 on Thursday. Weatherzone said strong westerly winds would make it feel four-five degrees colder.