Flood warnings in northern NSW as thousands stranded

A family with five children has been rescued from floods and thousands have been isolated, as heavy rain wreaks havoc in northern NSW.

The Bureau of Meteorology has issued flood warnings for several rivers including the Bellinger, Macleay and Hastings, and the State Emergency Service has issued evacuation orders for residents of Smithtown, Gladstone, Kinchela and Jerseyville, north of Port Macquarie.

State Emergency Service spokesman Phil Campbell said there are 3850 residents isolated in the area, and that number is expected to increase as the large river systems may flood and cut off roads.

Crews were particularly concerned about communities around the Macleay River, including Kempsey, Mr Campbell said.

The river is expected to exceed 6.4 metres at noon.

"There's part of the business district that could be affected by the flooding, so we're monitoring that situation very closely."

He said there had been 1320 calls for help and 16 flood rescues, including eight overnight in areas like Bellingen, Lismore and Nambucca.

Most of those were people trapped in their cars, and a family had to be rescued from their house at Glenreagh, north of Coffs Harbour, as water lapped at their doorstep.

Dorrigo, west of Coffs Harbour, has had 348mm since 9am on Friday.

Coffs Harbour has had more than 160mm of rain in the last 24 hours, which is half the average monthly rainfall for the area. Other places north of Taree have had as much as 200mm.

SES and fire crews were helping to clean up damage in Ballina, which was hit by 110km/h winds on Friday.

Meteorologist Tim Constable said the severe weather is being caused by an intense low pressure system tracking along the east coast from Queensland.

The bureau has issued a severe weather warning for heavy rain, strong winds and rough surf for much of the east coast, including Sydney, and the central tablelands.

It warns of flash flooding, damaging winds of 100km/h in some parts, and surf which may lead to damage and erosion.

Mr Constable said Sydney would be hit by two bands of rain today, one coming through the Hunter Valley and another coming from Taree.

"We will see the rainfall intensifying in Sydney over the next few hours."

He said rain across the state is due to clear up over the next two days.

This story Flood warnings in northern NSW as thousands stranded first appeared on The Sydney Morning Herald.