In the worst weather outbreak this winter, a woman has tragically died, and two children and a man taken to hospital after a tree fell on the family’s car during severe storms that have wreaked havoc across three states.

Victoria Police said on Friday afternoon the woman was a front-seat passenger in the car and she died at the scene.

The male driver has been airlifted to hospital in a critical condition.

One child was airlifted to hospital with life-threatening injuries and the other child taken to hospital by road ambulance with minor injuries.

Police said a gum tree fell onto the moving car as it was driving up the Maroondah Highway at Fernshaw on the Black Spur in the Yarra Ranges about 9.30am on Friday.

The tree crashed across the front of the car, crushing its bonnet and windscreen.

Two helicopters were sent to the crash outside Healesville and the Maroondah Highway between Healesville and Narbethong remained closed on Friday afternoon.

Victoria’s State Emergency Service issued a warning at 2pm on Friday for isolated minor flooding across the Upper Yarra and Bunyip catchments with forecasts of up to 20mm of rain and snow down to 600 metres overnight. 

3 people are being taken to hospital after a horrific crash on the Black Spur near Healesville.
A tree came down on their car at about 9:40am.
One person remains trapped in the wreckage. @10NewsFirstMelb pic.twitter.com/W6lgJpOVKr

— Annie Kearney (@anniemaykearney) August 9, 2019

Earlier, rough seas out on Port Phillip Bay crashed into Frankston Pier, tearing the end structure off and washing it ashore.

The SES said it had received 424 calls for help across Victoria in 24 hours, with the Mornington Peninsula and Bass Coast bearing the brunt of the damage on Friday morning.

Frankston worker Chris Ransom saw the piece of the pier floating away from his office building and told the ABC it appeared it was heading north.

“What’s left of the pier is still copping an absolute pummelling,” the Department of Transport’s Chris Miller told 3AW radio on Friday.

The area experienced wind gusts of more than 110km/h on Friday morning as a deep polar low moved across the region, leading to flight cancellations and bringing warnings of traffic chaos and blizzards.

“This is the coldest outbreak the south-east has seen this year,” Bureau of Meteorology duty forecaster Rohan Smyth said.

The weather bureau says three low-pressure systems are to blame for the high winds and sub-zero temperatures, with a forecast of more to come over the next 24 hours.

The weather caused chaos at Sydney and Melbourne airports, with multiple cancellations on Friday morning. Melbourne Airport said 23 domestic flights had been cancelled, but international services were not affected.

In Sydney, 20 flights were delayed or cancelled, with the airport down to a single runway. Both airports urged travellers to contact their airlines for more information.

Weather conditions across south-eastern parts of Australia today may impact your flight. Please check the Qantas Flight Status page for any updates: https://t.co/6TZNOujdF9

— Qantas (@Qantas) August 9, 2019

A Newcastle nursing home had its roof torn off as winds of up to 100km/h lashed NSW’s Central Coast. None of the 30 residents was injured and alternative accommodation was being sought.

In South Australia, conditions had eased early on Friday, but more than 5500 customers remained without power after outages across the state.

SA SES state duty officer Tony Costello said the state’s emergency service received about 340 calls for assistance in a “fairly hectic” 24 hours from Thursday into Friday.

The high winds and poor visibility made it difficult for emergency services to reach the scene of a fatal truck collision on the Stuart Highway near South Australia’s Barossa Valley region.

A severe weather warning remains in place for damaging winds across most of Victoria, as gusts hit 120km/h. More than 1500 people in Victoria were without power on Friday morning.

“Be aware of potential hazards caused by the severe weather. Hazards include damaged buildings, trees down, fallen power lines, debris and coastal erosion,” the warning reads.

Winds were expected to ease from about 9am in Melbourne and midday in eastern Victoria, with rain to follow.

Blizzard conditions are expected across alpine areas, with snow expected above 500 metres and flurries possible for the Dandenong Ranges.

Not a morning to ride to work! The bike path at Brighton battered by a storm surge and wind gusts up to 87 km/hr. Photo @windjunky – latest warnings https://t.co/mMvr0NqeCD pic.twitter.com/jFAm0KD2QR

— Bureau of Meteorology, Victoria (@BOM_Vic) August 8, 2019

Snow is also possible in parts of the ACT later on Friday. Canberra’s forecast maximum for Friday was just 8 degrees.

In Melbourne, a top of 11 degrees was expected, although the weather bureau said strong winds would make it feel much colder.

Elsewhere across Victoria, Ballarat was forecast to reach just 7 degrees and Mount Dandenong four degrees.

There is also a severe weather warning in place for parts of NSW, with damaging winds and blizzard conditions forecast for much of the state’s east.

Following the passage of a major front on Thursday, a second front was crossing the eastern part of NSW on Friday. A third front is expected on Saturday, bringing a major cold snap.

Vigorous westerly winds were affecting much of the state, especially the south-east, including Sydney, the Blue Mountains and the Hunter region, the Bureau of Meteorology said.

“It appears that today is the peak of the wind event,” a bureau spokesman said.

Snow 965m Cooma NSW, about 2.5 cm. pic.twitter.com/In88QbY6oR

— Dave Stewart (@davestewart3) August 8, 2019

Thredbo has already had a 118km/h gust at 3.50am on Friday, with Albion Park recording 100km/h and Bellambi 93km/h.

NSW SES spokeswoman Sharon Fox said the service had received 183 requests for assistance since midday on Thursday, many from the Blue Mountains and the Illawarra.

“The message is really clear – secure loose items around your yard or balcony, stay indoors away from windows and, if you can, move your vehicle undercover away from trees and powerlines,” Ms Fox said.

However, Victoria’s ski resorts, which have so far had lacklustre snowfalls this season, were expecting the winter storm to bring welcome snow to bolster low base levels.

“This dump of snow will increase the risk of avalanche, so skiers outside of resort areas should assess the avalanche risk,” BOM Victorian duty forecaster Rohan Smyth said.

The Great Alpine Road in Victoria has been closed between Harrietville and Mount Hotham due to heavy snow.

Just before 5.30am on Friday, the apparent temperature at Thredbo top station was -22 degrees.

The NSW National Parks and Wildlife Service has recommended backcountry travel be postponed until conditions improve.

-with AAP