Heavy rain across much of NSW could cause flash flooding across a stretch of coastline this weekend.
The Bureau of Meteorology had 13 flood warnings in place on Saturday morning as a rain band made its way slowly across the northeast quarter of the state.
Duty forecaster Andrew Haigh said the heaviest rain was expected to fall on northern parts of the Hunter region and the mid-north coast.
A severe weather warning takes in those areas as well as the northern rivers and northern tablelands forecast districts, with flash flooding on the cards at Newcastle, Forster, Port Macquarie, Kempsey, Coffs Harbour, Grafton and Tweed Heads.
At North Richmond in Sydney's northwest, the Hawkesbury River was holding steady at nearly 6.35 metres, causing minor flooding on Saturday morning.
Minor flooding was also occurring at Putty Road, where the Colo River was expected to peak about noon.
The State Emergency Service warned that caravan parks in the area could get a soaking and the Sackville and Lower Portland ferries had closed.