More rain is on its way though the downpour will be less severe than the deluge which has so far battered parts of Australia's east coast and threatened to cut off roads in one state.
A severe weather warning remains current for parts of the NSW mid-north coast and Hunter districts as a low pressure system lingers off the east coast, bringing heavy rain and thunderstorms.
Bureau of Meteorology senior forecaster Miriam Bradbury said severe thunderstorms, flooding and heavy rainfall swept from inland NSW to eastern areas on Sunday, hitting the mid north coast and the Hunter districts.
In the 24 hours to 9am on Sunday, the NSW mid north coast saw widespread rainfall of 50 to 100mm with 154mm recorded at Turner's Flat and 54mm in the Sydney suburb of Randwick.
The low-pressure system will deepen off the coast later on Sunday with a severe weather warning still current for much of the Hunter and southern parts of the mid-north coast.
"It's these areas which are most likely to see the six hourly rainfall rates reaching 50 to 100mm over the coming hours," senior meteorologist Miriam Bradbury said.
"That's a lot of rain to fall in a short space of time and is likely to lead to flash flooding in some of these areas."
Damaging winds are also still possible, generating large waves and dangerous surf.
A Flood Watch and several Flood Warnings are current including for the Bellinger, Hastings, Orara, Culgoa, Nambucca, Paroo, Camden Haven, Cooks and the Warrego Rivers.
SES NSW spokesman Andrew Edmunds earlier warned holiday makers to plan their trips home in case roads were blocked by floodwaters.
"Some roads will become impassable and in the context of the long weekend, a lot of people may be travelling so it's important to plan your trips and check conditions before you get out of the car," he told AAP.
In the 24 hours to 9am, SES volunteers had received 200 calls for help and attended 85 incidents.
The low pressure system will gradually pull away from the east coast of NSW by Sunday evening, easing the risk of heavy rain.
A showery day is on the way for eastern NSW for Monday but the rainfall totals are set to be much lower than Sunday.
"We'll still see showers through the east, but they're less likely to bring those heavy falls and the flash flooding," Ms Bradbury said.
The rest of the country can expect settled conditions with partly cloudy skies and a few passing showers moving through.
