NSW braces for more flash flooding as wet weather lashes Australia’s east coast

New South Wales is bracing for more flash flooding as another week of renewed rain lashes Australia’s already saturated east coast.

The Bureau of Meteorology’s Gabrielle Woodhouse said two “very significant” weather systems were moving across NSW over the coming days, with rain and thunderstorms expected over inland parts of the state from Tuesday.

A severe weather warning was active for heavy rainfall across New South Wales, northern Victoria and southern Queensland, bringing the renewed risk of flooding for parts of the east coast.

There were 15 minor to major flood warnings in place for catchments across inland NSW, with “widespread” moderate to major flooding expected.

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The BoM warned rain and thunderstorms would escalate on Tuesday night across south-west Queensland, western NSW and north-east Victoria before severe thunderstorms and heavy rain set in on Wednesday.

On Thursday, heaviest falls were predicted in south east and on the south coast of NSW, in north-east Victoria and elevated northern Tasmania, developing into severe rain and thunderstorms through central NSW and Victoria on Friday as the cold front moved east.

With a third consecutive La Niña under way, rain of up to double typical October levels was forecast in inland parts of NSW. Widespread daily totals of 20 – 40 mm were predicted on Wednesday across Queensland’s south, inland NSW and northern Victoria, with isolated totals of up to 100 mm possible.

“It’s fairly significant to get a month’s worth of rain in the space of a day or two … but that is falling on the backdrop of a really, really wet state … and fact that all of the rivers and the dams and all of waterways are so full,” Woodhouse said.

Senior meteorologist at the BoM, Dean Narramore, said with wet conditions on the ground, heavy rainfall was likely to lead to “widespread flooding” across large parts of southern Queensland, NSW and northern Victoria.

“It’s in NSW we could see widespread moderate to major flooding later this week into the weekend,” he said, predicting “even further” river level rises across saturated waterways in NSW and northern Victoria.

“A third burst of rainfall will sweep across southern Queensland, NSW and possibly eastern Victoria over the weekend with further heavy rainfall likely to further exacerbate already ongoing flooding.”

The NSW State Emergency Service commissioner, Carlene York, said the state was facing “continuous, rolling weather events” with saturated ground, overflowing dams and flooded rivers.

This week’s weather event comes off the back of a low pressure system and inland trough that brought rain and thunderstorms to Australia’s east, flooding catchments across central NSW.

The SES has received more than 60,000 requests for assistance this year, including 2,200 in September. There have been more than 100 flood rescues in the past month.

York said the SES would be concentrating on the western and central parts of the state over coming days, including the Namoi River at Gunnedah and Wee Waa, which was isolated by flooding in September.

The Barwon and Darling rivers in western NSW and the Culgoa River at Weilmoringle were also being watched, as was the Macquarie River at Warren, which was likely to peak near the major flood level of nine metres on Wednesday.

While metropolitan Sydney was not at “great risk”, according to forecasts, York said with rivers and dams full, the weather could do “unexpected things”.

“During the school holidays, it is an increasing risk of people travelling around the state,” she said.

“Every flood is different, and so, people should not assume that just because they haven’t been affected in the past, they’re not going to be affected in the future … have a plan.”

The NSW premier Dominic Perrottet said he had been in “regular contact” with the emergency services minister regarding what would be a “very difficult week” of heavy rainfall.

“We’ve got through the last flooding together and we’ll get through this together on the basis that everyone follows … instructions,” he said.