Winds of up to 140 kilometres per hour are adding to the havoc caused by heavy rain and flooding in northern New South Wales, as ex-tropical cyclone Oswald moves south.
More than 2000 people have been been cut off by floodwaters across the region, with motorists being warned to delay their travel.
A number of major roads are closed including the Pacific Highway at Grafton, the Gwydir Highway west of Glenn Innes, the Newell Highway at the Queensland border and the Bruxner Highway west of Tenterfield.
At South Murwillumbah, along the Tweed River, emergency services are door-knocking and telling people to move to higher ground.
An evacuation centre has been set up to cater for around 200 people.
Wind gusts have uplifted trees and power lines across the region. About 6,000 homes are without electricity.
Strong winds have torn part of the roof off the Tweed Hospital, with patients in the paediatric ward and a surgical ward moved as a precaution.
Richard Adams operates seven caravan parks, including one at Kingscliff, 10 kilometres south of Tweed Heads.
He says the wind has been relentless.
"Well in a word, horrendous, it's blowing I'd say 45 to 50 knots, that's probably close to 100 kilometres an hour," he said.
"The seas are turmoil, there's spume coming in, flowing into the park and we've had a fair bit of structural damage to a number of caravans and annexes.
"We've got some trees down, we've got some structural damage to some of our amenity buildings."
The New South Wales State Emergency Service (SES) has been dealing with about 1000 calls for help.
A man has been rescued from the roof of his car this morning.
The SES says he was trying to drive through a flooded creek at Murwillumbah, near Byron Bay, when he was forced to stop and climb onto the car roof and call for help.
Libby Spash from the Richmond-Tweed SES says there have been 15 rescues overnight in the region.
She says some residents are not heeding safety messages.
"That person was driving through a flooded creek,"
"As we have advised people, we don't drive through, walk through or ride through flood waters.
"It's a good example of what can happen."
There are flood warnings in place for the Tweed, Richmond and Wilson, Bellinger, Clarence, Hastings and Brunswick Rivers.
Volunteers have been sandbagging homes and businesses.
The Weather Bureau's Julie Evans says the heavy rain and strong winds are expected to reach Sydney by midnight.
"It is tracking down today, and we do expect it to reach Sydney later," she said.
"It has slowed down a little bit, so we do expect the peak in Sydney to be overnight now, rather than in the evening, which is what we were saying yesterday."
SES Commissioner Murray Kear says holiday-makers returning home after the long weekend should consider their options.
"I'm just asking people to think about their travel plans today," he said.
"If they can delay them for the next 24 hours, that would be great, but if they have to travel on the roads to be really really careful and follow the directions of emergency services throughout the day."
© ABC 2013
01:01 EDT A two-year-old boy has died and a girl suffered serious injuries after a tree fell on their house at The Patch in the Dandenong Ranges, east of Melbourne, as severe thunderstorms swept through Victoria on Saturday evening.