Flood warnings across two states as more wild weather forecast

Residents in NSW are being urged to prepare for more wild weather as the system causing dangerous flooding in Queensland travels south.

Flood warnings were in place Monday morning for large parts of Northern NSW with the first day of the week expected to be “critical” for the state and even wetter than the weekend.

Areas north of Nambucca Heads, on the Mid North NSW coast, were expected to be drenched the most, with up to 100mm set to fall by the end of today.

“We could see greater than 50mm over a broad area in that region, with potential for up to around 100mm over the 24 hours,” Weatherzone meteorologist Tom Hough told Yahoo News Australia.

“There’s still some fairly significant rainfall expected for another day across that region.”

Flooding warnings for NSW north coast

It comes after parts of South East Queensland and Northern NSW were lashed by wild rain on Sunday, with some areas receiving more than 400mm in just 24 hours.

River flooding and significant rain is due to hit the mid north coast - as far down as Forster - and the Northern Rivers region.

Minor to moderate flood warnings have also been issued for the Tweed and Bellinger Rivers and a minor flood warning has been issued for Brunswick River and Marshalls Creek.

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“The heaviest rainfall will probably be further north, north of Coffs Harbour,” Mr Hough said.

“The most significant event will be today, and it will gradually ease over the coming days.”

Some reports suggested the system could cause between 300 and 600mm to fall in the three day period from Sunday to Tuesday.

With Upper Springbrook on the Gold Coast receiving 424mm yesterday, Mr Hough said this was “certainly possible”.

The Logan, Albert and South Coast River catchments in South East Queensland are now saturated with renewed river level rises expected with forecast rainfall on Monday, the bureau said.

More than 700 calls for SES help over weekend

There were more than 50 calls for help overnight to the NSW State Emergency Services overnight as residents suffered in the torrential conditions.

The SES says more than 700 calls for help have been made since Friday and 57 overnight, while a severe weather warning for very heavy rainfall is current for the Northern River areas.

More SES personnel have been sent to the affected area to help after volunteers performed five flood rescues over the weekend in the northern rivers areas, Tweed Heads and Byron Bay.

The SES said heavy rainfall over Leycester Creek and the Wilsons River at Lismore is likely to reach the minor flood level (4.20 metres) around midday on Monday with roads and low lying farm land and rural properties most likely to be inundated with flood waters.

The SES says the flood situation is being monitored and revised warnings will be issued should the situation change.

People in areas likely to be impacted by flooding should refrain from driving or walking through flood water, take note of road closures and monitor emergency warnings and severe weather updates.

Thunderstorms could lead to dangerous flash flooding

The BOM says thunderstorms could lead to the possibility of very heavy rainfall and dangerous flash flooding.

"At this stage, the widespread heavy rainfall is expected to ease late Tuesday or early Wednesday," the BOM said.

"Thunderstorms may still produce localised heavy falls that may lead to flash flooding during Wednesday."

The BOM also warned damaging winds averaging 60-70km/h were likely along NSW's coastal fringe from Yamba to as far south as Crescent Head on Monday.

Waves possibly exceeding five metres in the surf zone could also be expected from Yamba to Port Macquarie.

Communities in flood-prone areas spent Sunday sandbagging low-lying areas and preparing properties.

A surface trough was expected to deepen off the southeast Queensland coast on either Sunday night or Monday morning, the BOM said.

Meanwhile, a flood warning is in place for Western Australia's De Grey River catchment after a tropical low dumped heavy rain from the Pilbara to the border with South Australia.

With AAP

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