Sydney weather: Three killed, homes washed away in Dungog as 'cyclonic' 135kph winds batter NSW.

Three people have been killed in wild weather in NSW’s Central Hunter region, where homes have been washed off their footings in the town of Dungog, north of Newcastle.

Emergency crews have been battling “cyclonic” conditions, which have already brought heavy rain and wind gusts in excess of 135 kilometres per hour.

The State Emergency Service (SES) this afternoon sent an emergency alert to more than 100,000 people in the Newcastle area, warning of another developing storm cell.

Premier Mike Baird said the weather was likely to worsen in the coming hours, and people in affected areas should consider leaving work early.

Mr Baird said the three people killed this morning in Dungog were elderly residents.

“At the moment, the circumstances are being worked through but we do want their families to know our thoughts and prayers are with them,” Mr Baird said.

“It is too early to say what has happened.”

An evacuation centre was set up in the town following reports at least 20 homes had been damaged by flooding.

Hunter police commander Jeff Loy said several homes had been washed away in the town.

Meanwhile, a school bus had been washed off a road near Maitland, and several Hunter homes had been split in half by falling trees.

Tens of thousands of people are without power and SES crews have answered more than 4,500 emergency calls as wild weather associated with a low off the east coast batters Sydney, the Hunter and the NSW Central Coast.

The Bureau of Meteorology (BoM) reported 119 millimetres of rainfall in the 24 hours until 9:00am at the Sydney Observatory Hill – the wettest 24-hour period since 2002.

The SES said “unprecedented” wind gusts of up to 135kph had lashed the Hunter, with dozens of houses losing their roofs, thousands of trees down, and more than 200,000 properties without power across the state – the largest outage since 2007.

Dozens of people have been rescued after being trapped in buildings, on roofs and in cars.

Mr Baird said rescuers had conducted 47 flood rescues, and 3,000 people had called triple-0 on top of the thousands of requests for help from the SES.

Several hospitals were being powered by back-up generators, and crews were working to restore power to health facilities and aged care homes as a priority.

“Those requiring support, in terms of ongoing life support, is obviously the focus,” he said.

He said people in affected areas should consider leaving work early, as the weather was likely to worsen in the coming hours.

“So there is strong advice to everyone across the greater metropolitan area, that is from Illawarra to Newcastle, to start to head home as soon as possible,” he said.

“We are calling for bosses to be flexible, people to make arrangements in an orderly way to start to head home as soon as you possibly can.”

Forty-seven schools had been closed, mainly in the Hunter, and some would remain closed tomorrow, he said.

The BoM said another low pressure system wasforming off the Central Coast and was expected to move into the Hunter and coastal areas this afternoon.

A severe weather warning is in place for locally destructive winds, heavy rainfall and damaging surf in the Sydney Metropolitan, Hunter and Illawarra districts.

“Extremely busy is an understatement,” SES Deputy Commissioner Steven Pearce said.

“We’ve received just under 3,000 calls for assistance [in the Sydney, the Hunter district, Central Coast and Illawarra] within a 24-hour period, which is enormous.

“We’ve haven’t seen this sort of weather pattern, this east coast low, or one as severe as this, in years.

“The consistent gale force winds … are actually cyclonic in some areas with gusts up to 135 kilometres per hour.”

Dungog shire community centre manager Sarah U’Brien said residents had never seen anything like the extraordinary weather.

“We’ve got a lot of low lying houses in the township near rivers and unfortunately a lot of those houses have gone under,” she said.

“It sort of happened in the middle of the night, so people, there wasn’t a lot of notice.

“We’ve lost about five houses, there’s at least 20 houses had running water rush through them.

“We’ve got a lot of people who have nowhere to call ‘home’ at the moment.”

SES crews had to carry out a number of swift-water rescues after floodwaters swept through the Stroud campground in the Hunter.

Councillor Karen Hutchinson described the area around the council-owned site as a disaster zone.

“The front fences are gone, the fence around the pool is gone,” she said. “There are buildings destroyed; the grandstand has been blown out at one end. [There] is huge damage.”

One Central Coast resident, David, told 702 ABC Sydney he was at Avoca Beach when he saw fellow walkers washed into the lagoon by a giant wave.

“It was just lucky they got washed into the lagoon… rather than back into the surf,” he said.

“I think they were walking their dogs of all things.”

“The wind is just howling down there…it’s quite spectacular, but so incredibly dangerous.”

Near Gosford, local MP Lucy Wicks said she had a lucky escape when a tree flattened her car after falling through her house at Springfield.

“Hearing the crack of the tree coming across the house at seven o’clock this morning probably not the sound I wanted to hear,” she said.

“For us, the tree has gone through the lounge room, through a balcony and unfortunately onto our car.”

Power crews were battling to repair the damaged network but it is expected that some households’ electricity may not be restored until Wednesday.

Superintendent Wayne Phillips from NSW Fire and Rescue said coastal areas were bearing the brunt of the storm.

“The areas most affected are from Sydney to Newcastle. We’ve got numerous wires down, trees down,” he said.

The severe weather warning continues today for damaging and locally destructive winds, heavy rainfall and damaging surf across the Sydney, Mid North Coast, Hunter and Illawarra regions.

The Hunter and Mid North Coast are expected to suffer through the worst of today’s wild weather, with about 200 millimetres of rain and gale force winds of up to 100 kilometres per hour forecast.

Meanwhile, there were reports of an 11-metre wave off Sydney.

A number of major roads and rail lines have been closed in Sydney and around the state as a result of the wild weather.

The Princes Highway is closed at Sydenham because of a fallen power pole, the Bells Line of Road is closed at Kurrajong and flooding has closed the Wakehurst Parkway and Oxford Falls Road near Sydney’s northern beaches.

Train services have been cancelled between Newcastle and Sydney as well as between the Central Coast and Newcastle.

Brett Moore from the Transport Management Centre said the best approach may be to stay home today.

“If you can be home today, it may be a good option as the incoming weather has affected the roads and the public transport network,” he said.

“If you don’t need to be out on the road, probably best not to be.”

Transport NSW cancelled the Manly Fast Ferry service due to the weather conditions and heavy swell.

Courts are closed in Newcastle, East Maitland, Singleton and Wyong due to the wild weather, NSW Justice said.

This post originally appeared on ABC Online.