Three people have died in the worst storms to hit NSW in a decade with the battered Hunter region bracing for further cyclonic conditions.
A woman and two men, all believed to be elderly, reportedly died in their homes in Dungog as water surged through the town, after more than 300mm of rain fell in 24 hours.
The deaths came after dramatic footage emerged of a house floating down a Dungog street with wild weather wreaking havoc across the state, including Sydney.
Rescuers have saved more than 100 people from floodwaters, 10 of them from rooftops in Stroud, just north of Newcastle, with the SES fielding 6,200 calls since Monday morning.
Wind speeds topped 130kmh, taking down power lines and forcing three Hunter region hospitals to use back-up generators.
A man who escaped Dungog through a back route says the town is a mess as families have been left with nothing.
Animals have been floating in the streets and people have been swimming onto their roofs, David told ABC Radio after he checked on his wife's family in town.
"People don't understand, Dungog has been smashed," said David, who didn't give his surname.
"The town is a mess. People have got nothing ... it's just been horrendous."
More than 200,000 homes and businesses have been left without power as Premier Mike Baird urged people to be patient with power companies.
"Obviously getting power back to places such as our hospitals, I mean that's an absolute priority ... and people on life support," Mr Baird told ABC Radio.
The premier also urged people to check on elderly neighbours throughout the night and on Wednesday following the Dungog tragedy.
Wild weather is set to continue in Sydney, which is in for another belting as the storm cell moves south.
Transport chaos ensued across the city on Tuesday night after trees fell onto North Shore train lines and roads became clogged with workers rushing home.
A cruise ship was left stranded outside Sydney Heads because of a massive swell, while winds in Bondi whipped up sand and covered the skate park at the iconic beach.
The SES has warned Manly residents to be prepared for flooding from the Manly Dam, while Newcastle locals have received similar warnings, especially for those in low-lying streets.
"These events are going to test our emergency services," Emergency Services Minister David Elliott said.
Close to 80 public schools will remain closed across NSW on Wednesday as the east coast low is expected to start easing.
The premier called on bosses to be flexible and for people to avoid roads unless necessary.
