Residents in south-west Sydney have been advised to evacuate as a damaging weather system wreaking havoc in New South Wales moved south.

More than six million people in the NSW capital were warned to prepare for delays, blocked roads and flash flooding.

On Friday afternoon, the SES issued ‘prepare to evacuate’ notices for Chipping Norton due to minor flooding, in particular around Rickard Road, Riverside Road and Arthur Street.

Residents of Cobbitty, south-west of Sydney, were also advised to leave.

Police warned drivers in metropolitan Sydney to exercise caution in wet weather after two deaths overnight — including a 95-year-old hit by a car in Liverpool.

It comes as the discovery of a man’s body in a vehicle near Coffs Harbour on Friday became the fourth confirmed flood death.

According to the SES, flash flooding has already impacted some areas on Sydney’s fringes.

A watch and act warning is in place for Gronos Point in north-west Sydney as the Hawkesbury River rises.

Advice warnings have been issued for areas in Liverpool, Tempe, Richmond, Windsor, Colo and Milperra.

The Warragamba Dam is at 97 per cent and could spill on Friday or Saturday.

“Water NSW are not anticipating a spill … but depending on where that rain falls, there is still a potential,” NSW SES deputy commissioner Damien Johnston said.

Authorities are also keeping a close eye on the Hawkesbury-Nepean and Warragamba rivers.

The last time they overflowed was in 2022, when around 85,000 people were displaced.

The current trough which has left 50,000 people isolated across the mid-north coast and Hunter regions, was expected to move south of Sydney on Friday afternoon.

Prime Minister Anthony Albanese and Premier Chris Minns planned to visit hard-hit Taree on Friday morning, after days of intense rain killed four people and isolated thousands across the NSW mid-north coast.

But the pair’s attempt to meet affected locals was aborted because of flooding, further highlighting the town’s isolation as it endures its second major flood in four years.

“Conditions in Taree are very tough,” Minns said from Maitland.

“We’ve heard word from local MPs and businesses that they’ve had a torrid three days, incredibly difficult circumstances.

“We know it will take a long time to get that community back up on its feet … as (12.30pm), local roads are still cut off to Taree.”

There are grave fears for a man missing in Nymboida and police have not ruled out floods as a factor in the disappearance of a man in Bellingen.

But hundreds of people would be dead without SES volunteers, the premier said.

“We’re in deep, deep gratitude to those people,” Minns said.

Four people have died and hundreds of residents have been rescued as floods wreak havoc in NSW.

The prime minister announced personal hardship assistance grants of $180 per person or $900 for a family would roll out in coming days.

Those unable to work in the hardest-hit areas will be able access a disaster recovery allowance from Monday afternoon.

“Tragically, we’re seeing more extreme weather events. They’re occurring more frequently and they’re more intense,” Albanese said.

There had been more than 675 flood rescues, including 177 in the 24 hours to 5am on Friday, the SES said.

But with the rate of flood rescue requests decreasing, the SES is focusing on getting supplies to the 50,000 people still isolated by floodwaters.

Locals in Port Macquarie also took things into their own hands, boating food to people in the city’s northern suburbs.

“There have been some communities that have been cut off for quite some time, where vehicles can’t get in,” NSW SES deputy commissioner Damien Johnson said.

The slow-moving trough that dumped months of rain over the mid-north coast has shifted south, bringing heavy falls to the Hunter, Blue Mountains, Sydney and Southern Highlands.

That will deliver dry conditions in the flood-ridden areas but residents are not out of the woods yet.

“There are waters still moving quite quickly through the river systems, a lot of debris around so it’s quite dangerous,” Bureau of Meteorology’s Jane Golding said.

Wind is also expected to pick up on Monday and Tuesday, potentially uprooting trees and buildings from sodden soil.

Heavy falls potentially totalling 150 millimetres in 24 hours could bring flash flooding at Goulburn and south to Bega, the Bureau of Meteorology has warned.

Disaster assistance from the state and commonwealth governments has been expanded, with 19 areas now eligible for support.

People who want to donate items such as clothes, food or money to those affected can do so via GIVIT, a non-profit organisation partnered with the government to support communities impacted by flooding.

The Nepean Dam is spilling while Australia’s largest urban water supply, the Warragamba Dam, may spill depending on where rain falls on Friday, the SES said.

Earlier, train services were thrown into disarray across the central region as floodwaters halted services in the city loop, Blue Mountains, Mittagong, Cockle Creek and Sandbridge.

More than 200 millimetres of rain fell in Richmond, about 90 millimetres in Camden, more than 50 millimetres in Katoomba and at least 75 millimetres at Sydney airport in the 24 hours to 9am on Friday.

Parts of the Illawarra copped more than 200 millimetres, including Clover Hill, causing localised flooding on the coast.

Sydney and Blue Mountains are expecting a further dumping of up to 100 millimetres over the next 24 hours.

“Our message is not only to the drivers in the rural areas, but drivers in metropolitan Sydney as well, please drive to the conditions,”  acting police commissioner Peter Thurtell said on Friday.

An elderly man was killed after a 36-year-old driver struck him in western Sydney on Thursday evening.

Meanwhile, two trucks collided in the city’s southwest on Friday morning, killing a passenger.

Police did not draw direct links between the crashes and wet weather but urged caution.

“Accidents increase particularly during night-time hours in wet weather,” Thurtell said.

-with AAP