As much of NSW enjoys a public holiday, a band of clouds continues to pose a flooding risk across large parts of the state, with active weather warnings inland and through to the coast.
Communities on the Mid North Coast, the Hunter and the Northern Rivers have been warned of possible flooding on Thursday, with heavy falls forecast across already saturated catchments.
"Heavy rainfall for the Hunter, the Mid North Coast and even the Northern Rivers can't be ruled out," Bureau of Meteorology senior meteorologist Jenny Sturrock said on Wednesday.
Thunderstorms are likely to develop in the afternoon, with heavy localised rainfall potentially dumping up to 120mm in six hours.
The heavy rain could spark flash flooding on the Mid North Coast and Northern Rivers throughout Thursday and into Friday, with Lismore, Grafton, Taree and Coffs Harbour among areas to be affected.
The SES has warned residents and people travelling around the state to monitor the weather and road conditions and avoid unnecessary trips.
"With heavy traffic expected over the coming days, we can expect unfavourable conditions to cause extra hazards to road users," NSW SES superintendent Joanna Jones said on Thursday.
The SES has spent the week preparing, with assets deployed to the Mid North Coast near Port Macquarie and work around Casino and the Northern Rivers to respond to the evolving situation.
The service is reminding people not to enter floodwaters after it conducted two rescues on the Coffs Coast.
Multiple rescues were also conducted in Warren, west of Dubbo, where major flooding on the Macquarie River is forecast to continue for several days.
People have been rescued from vehicles submerged in floodwaters on Ellengerah Road, which runs alongside the river.
The town is protected with a levee although it has deteriorated in recent years.
The local council was awarded a $5.3 million federal grant to begin rehabilitation works in May.
The threat of further flooding comes after severe thunderstorms with large hail, heavy rain and damaging winds hit inland NSW and southern Queensland on Wednesday.
Flooding impacted the inland towns of Dubbo, Gunnedah and Tamworth on Wednesday afternoon and major flood levels were reached on the Lachlan, Narran and Macquarie rivers, Ms Sturrock said.
Helicopters prepared to deliver supplies to the town of Wee Waa, between Narrabri and Walgett, as flooding cut the Kamilaroi Highway in both directions.
Light to moderate falls across saturated catchments have the potential to trigger significant flood responses, Ms Sturrock.
She urged the community to stay up to date with warnings from the BOM.
Wee Waa is already experiencing major flooding, with water levels expected to rise further on Thursday.
Moderate flooding is also expected along the Peel River in Tamworth.
