Sydney expects flash floods as torrential rain sweeps south

The New South Wales flooding death toll has risen as the state braces for further flooding, while tens of thousands of residents in Queensland are still without power with more storms forecast.

Authorities have recovered the body of a man in the main street of Lismore following this week's flood emergency, the third death in NSW from the flooding.

It follows the discovery of two women, both in their 80s, found inside their homes yesterday.

At least eight people have also died in flooding in Queensland.

Some 30,000 people were still without power in south-east Queensland

In northern NSW, Ballina is isolated this morning as several evacuation orders were issued from yesterday.

The local hospital has been evacuated.

NSW State Emergency Service (SES) acting assistant commissioner Greg Swindells said the extent of the flooding forced the evacuation order to be extended to Ballina Island this morning.

"Directing people to ... evacuate as soon as they can due to the unprecedented flooding," he said.

Those living elsewhere in the state - including Sydney - are warned extreme weather is coming their way.

Dangerous weather is predicted to move south as a low tracks down the east coast, bringing with it torrential rain and damaging winds.

Authorities have issued severe weather warnings from the Hunter to the South Coast and Queanbeyan, and Premier Dominic Perrottet ominously said yesterday the "worst could be yet to come".

With the Bureau of Meteorology (BoM) saying up to 200mm of rain could fall within just six hours in parts of NSW, residents in Sydney and the Central Coast were busy sandbagging flood-prone areas last night.

This morning, a number of flood warnings have been issued for the Sydney area:

• Minor to moderate flooding is likely along the Nepean River at Menangle Bridge with further rises possible this afternoon.
• Minor flooding is occurring along the Hawkesbury River and this could increase to moderate flooding by this afternoon. North Richmond and Windsor could reach the minor flood level this afternoon and moderate flooding is possible by tonight.
• There is minor flooding along the Colo River at Putty Road.
• A minor flood warning is in place for the Georges River at Liverpool and Milperra
• The SES is advising those impacted by flooding to place moveable items like furniture and electrical items on bench tops or tables and relocate livestock and farm equipment to higher ground.

Senior meteorologist Dean Narramore said the good news was that the state's north was not expected to see any more widespread rain - even if it would take a long time for floodwaters to subside.

However, Narramore said the low-pressure system that has caused unprecedented rain and flooding was moving south and would threaten a large part of the state.

"That includes Newcastle, the Sydney metropolitan area, Wollongong, and inland toward the Blue Mountains and our communities that are sitting through the hills from the Hunter all the way down to the south coast of NSW," he said.

"A severe weather warning is current for heavy rain and damaging winds for today and tomorrow for much of this coastline, extending from Newcastle all the way down to around Bega."

Narramore said the worst of the weather would hit south of where the system crosses over the land, which remained unclear.

He flagged the Hawkesbury, which suffered major flooding just one year ago, as an area of concern.

Despite the rain moving on, SES Commissioner Carlene York said operations would stay focused on life-threatening work in the state's north for now.

"There will be storms, there will be trees down, there will be roof damages, there will power breakages," she said.

"But I ask the community to be patient because we will be doing rescue operations first and prioritise that over property damage."

Last night, the SES said people in low-level areas near waterways including the Hawkesbury, Nepean, Cooks, Georges and Woronora rivers should take measures to protect their homes against flooding.

Police and local SES crews issued an appeal to motorists in several Marrickville streets in anticipation for roads in the inner-west Sydney suburb to become inundated.

Speaking at a press conference in Sydney yesterday, Perrottet said flooding in the state's north remained a real risk to people's lives - and the danger was moving.

"I also want to say as well, we know that at the moment this is focused on the north. But very quickly, as we're seeing in metropolitan Sydney now, it will move to the south," he said.

"We say to people across our city and across our state, look after yourself, follow the advice, stay safe and we'll all get through."

The Insurance Council of Australia said more than 40,000 insurance claims had been received, mostly from Queensland, but chief executive Andrew Hall said more were starting to flow through from New South Wales.

Queensland Premier Annastacia Palaszczuk, speaking on News Breakfast, said the cost of the flood damage in the state could reach $1 billion.

"I'm expecting this will be into the millions if not hitting the billion mark. It's just phenomenal. See, it's not just people's homes and their businesses, it's also the road networks, it's the parks, it's so widespread, across such a large area."

- ABC