Heavy rain is expected to persist throughout the NSW mid north coast and in parts of the Northern Rivers region overnight but forecasters say conditions should ease on Sunday.
The state has endured a drenching with Saturday's rainfall potentially exceeding 250mm in some parts of the Northern Rivers, mid north coast, Hunter and Northern Tablelands areas, the Bureau of Meteorology said.
Forecasters on Saturday evening issued another warning for damaging winds and potential flash flooding, saying Yamba, Coffs Harbour, Port Macquarie, Taree, Sawtell and Dorrigo were all in the firing line.
But conditions on Sunday are expected to ease as the low-pressure system behind the widespread rain weakens, BOM said.
The SES on Saturday afternoon had received more than 550 calls for help since 5am and responded to at least 2750 requests since the soggy weather began earlier this week.
There have also been more than 70 flood rescues, most on the mid north coast and in the Hunter, SES spokesman Brent Hunter told AAP.
He said many rescues involved people driving in floodwaters and in one instance, the SES had to call police to stop people entering Audley Weir in the Royal National Park south of Sydney.
"We have had people disregarding the warning signs and walking across the weir, which obviously is idiotic in itself," Mr Hunter said.
"It's a quick way to end your life."
The SES had 180 teams ready to respond to further incidents, which included about 650 volunteers.
Areas of the mid north coast that had already experienced a drenching in the 24 hours to Saturday morning included Careys Peak in the Williams Range (179mm), Bellingen (142mm) and Red Hill in Coffs Harbour (135mm).
