The State Emergency Service says Saturday and Sunday are of concern for them, as the worst of the rain is expected to hit the Hunter over the next 24 hours..
Heavy rainfall which may lead to flash flooding may develop about the region from Saturday afternoon and into Sunday morning, with six hourly rainfall totals between 30 to 50mm likely, with isolated falls about 70mm also possible.
Damaging winds are also forecast, but these are expected to weaken late Sunday as the low moves away.
The Wollombi Brook and Lower Hunter River are on the radar of emergency services, as major flooding is possible over the weekend.
It comes as communities along Wollombi Brook are still mopping up the damage from the July flooding event.
The Paterson and Williams Rivers have also been put on alert for minor flooding.
Locals are being advised to stay up-to-date with the latest information and call the SES on 132 500 for emergency assistance and Triple Zero (000) for life threatening emergencies.