UPDATED: WILD weather lashed Sydney, the Hunter Valley and Illawarra on Tuesday with gale force winds and torrential rain flooding the Upper Hunter.
Flash flooding in Dungog claimed the lives of three elderly people, while four houses were washed away, the Dungog Chronicle reports.
NSW Police said a woman and two men were located deceased within the Dungog township this morning after heavy rain fell all of Monday night.
Two men and one woman were trapped in their residences as flood water surged through the town in the early hours of Tuesday. Emergency services could not save them.
NSW Police advised residents in Dungog and surrounding areas to leave the town to avoid floodwaters.
Residents were told to stay with with family or friends and evacuation centre has been set up at the Dungog High School, Eloiza Street, Dungog.
Dungog's Main St on Tuesday morning. Pic: Brodie White
NSW Premier Mike Baird advised people to leave work early on Tuesday afternoon, as the weather was forecast to worsen overnight.
"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."
The Premier reiterated warning from emergency service crews not to enter floodwaters.
Floodwaters in Stroud, in the Hunter Valley, on Tuesday morning.
Hunter region floods
People were rescued from Stroud Showground on Tuesday morning when floodwaters washed away campervans and caravans.
Newcastle Herald reported one woman who was trapped on a roof is understood to have suffered a cardiac arrest.
"It's basically like a flood island. They're safe but we just can't get access to them due to no light and also the ferocious winds," SES Deputy Commissioner Steven Pearce told the ABC.
Reports stated as much as 260 millimetres fell in the area in the last 32 hours.
At Martins Creek, north of Paterson, near Maitland, a school bus driver was winched out after the bus was washed off the road at Martins Creek.
NSW Police Force confirmed there were no children on the bus at the time.
The Paterson and Williams Rivers have swelled on Tuesday morning with 200mm of rain that has fallen in parts of the district on Monday night.
The Bureau reported record major flooding, which is forecast to gradually ease on Tuesday night.
The river level Gostwyck Bridge at Dungog peaked 16 metres at 4pm on Tuesday afternoon.
The Myall River at Bulahdelah has fallen below minor flooding level.
Damage at New Lambton, Newcastle. Photo: Newcastle Herald.
Sydney, Newcastle in chaos
Metropolitan areas of Sydney and Newcastle have been thrown into chaos. More than 140,000 homes were without power on Tuesday.
Wind gusts up to 100km/h felled trees took out powerlines and blocked roads.
Fire and Rescue NSW Commissioner ordered the mobilisation of 24 reserve fire trucks and the recall of off-duty firefighters.
Commissioner Greg Mullins said on Tuesday Fire and Rescue NSW had about 800 firefighters and 200 fire trucks responding to ongoing emergencies in the Sydney and the Blue Mountains, Central Coast and Newcastle areas.
A Raymond Terrace firefighter was injured last night when a large tree fell on a fire truck cabin at Heatherbrae, Port Stephens. The firefighter was transported to hospital with minor injuries and is in a stable condition.
Firefighters were trapped in the cabin of their fire truck at Morriset when a tree that brought down powerlines fell on top of their vehicle.
NSW Department of Education advises some schools in Sydney and the Hunter have been closed by the severe weather.
NSW SES are responding to over 4470 jobs across the state since 7am Monday. The worst hit regions are pictured in the infographic.
"We've haven't seen this sort of weather pattern, this east coast low or one as severe as this in years," Deputy Commissioner Pearce said.
"The consistent gale force winds which are actually cyclonic in some areas with gusts up to 135km/h."
A deepening low pressure system has caused the heavy rain and strong winds.
The Hunter and Mid North Coast are expected to bear the brunt of today's wild weather, with about 200mm of rain and gale force winds of up to 100km/h forecast.
Warning to sheep graziers
Sheep graziers in the Illawarra, Southern Tablelands, Central Tablelands and Hunter have been warned by the Bureau of Meteorology there is a high risk of losses of lambs and sheep exposed to today's weather conditions.
To report an incident phone SES on 132 500. Life-threatening jobs take priority and people are urged to be patient. In a life-threatening emergency call 000.
