Residents across NSW are being warned thunderstorms forecast for Sunday could dump up to 150 millimetres of rain and cause further flooding across western NSW.
Bureau of Meteorology forecaster Jake Phillips said storm activity could begin this afternoon as a trough moving in from the west of the state met with a cold front, and there was a high chance storms would become severe tomorrow.
"A broad area of the state could see thunderstorms from tomorrow," Mr Phillips said.
"The nature of the system is that all the ingredients, including warm weather, are there and we could see them develop any time.
"Our biggest concern is for areas already affected by flooding."
A severe weather warning for heavy rainfall around the South West Slopes, parts of the Southern Tablelands, Riverina, Snowy Mountains, and the Australian Capital Territory has also been issued for this afternoon.
Emergency Services Minister Steph Cooke said wherever the rain fell it would have an impact, but the biggest concerns were the Murray and Murrumbidgee Rivers.
"Any additional rainfall, and we are expecting up to 150mm, will cause flash flooding and riverine flooding," she said.
"The SES remains on alert and their preparation is continuing around the clock.
"It is very difficult to say at this point in time what the impact will be because these thunderstorms are unpredictable."
Thunderstorms with heavy rain could also develop on the east coast, south of Newcastle, however Mr Phillips said the worst of them were likely to be inland.
Exhaustion is setting in, but volunteers battle on
Saturday marked the 60th consecutive day of the flood event in NSW.
Ms Cooke said emergency service volunteers were doing their best, but they were fatigued.
"There hasn't been a day in 2022 where our volunteers haven't been out helping with either a response or in the recovery phase of these events," she said.
"They are fatigued, but spirits remain high."
The SES has been working to resupply a number of communities isolated by flooding in Collarenebri, Walgett, Lightning Ridge, Goodooga, Brewarrina and parts of Bourke during the past few weeks.
NSW SES Assistant Commissioner Nicole Hogan said it was a complex and evolving situation.
"The size of the area is about 40,000 square kilometres – more than half the size of Tasmania," she said.
"Roads have intermittently been cut for several weeks now, with resupply missions needing to take place by airplane to regional depots, before being loaded onto helicopters and finally transported by vehicles and boats to the desired recipients.
"With renewed flooding expected, we anticipate this remote outreach will need to continue for some time.
"We are conducting regular flights to ensure the 5,000 or so isolated residents receive the essential foods, medicines, mail and essentials they need," Ms Hogan said.
Groundhog Day for farmers
Gunnedah Mayor Jamie Chaffey said most of the community was ready for another system, but it had been a devastating 12 months.
"It's deja vu, we've been here so many times before," Mr Chaffey said.
"Those who can harvest crops are trying to get out there and salvage what they can before this next system.
"There has been a billion dollars worth of loss in north-western NSW."
Ninety-four warnings remain in place around NSW with 11 currently at emergency status.
The weather is expected to settle across the state from Monday night.
