A man has died after his vehicle was lost in floodwaters on the NSW Central Coast overnight.

The body of the 54-year-old Matcham man was found in a Toyota LandCruiser near the Maddens Creek crossing at Matcham, east of Gosford, about 1.30am on Friday.

Emergency services were called after reports a vehicle had gone missing in floodwaters at about midnight.

A report is being prepared for the coroner.

The man’s death comes after several areas on the Mid-North Coast and Central Coast were smashed with more than 100mm of rain in 24 hours.

Between 9am Thursday and 7am Friday, Bateau Bay recorded 116mm, Erina Heights 136mm, Mount Elliott 115mm, and Wamberal Reservoir 140mm and Gosford 136mm.

Further north, Bellingen recorded 173mm, Bowraville 112mm, Dorrigo 103mm, and Glennifer 135mm.

In the two hours up to 11am on Friday, a further 18mm of rain fell at Gosford, while south of Sydney in the Illawarra, Port Kembla received 19mm.

Girralong and Thumb Creek on the Mid-North Coast both recorded 15mm as rain continued on Friday morning.

Near the border, Numinbah picked up 13mm in the same time.

Torrential rain is expected to continue on the north coast of NSW on Friday as Sydney rounds out what is likely to be its wettest summer in three decades.

An offshore surface trough near the Qld-NSW border is expected to bring further downpours to southeast Qld and northern NSW on Friday.

Bureau of Meteorology meteorologist Dean Narramore says isolated rainfall totals in some areas stretching from Byron Bay in NSW up to the Fraser Coast in Qld could exceed 300 millimetres in the coming days.

“This is a dangerous set-up as very heavy rainfall falls over already saturated soils,” Mr Narramore said.

The SES has issued an evacuation warning for low lying areas along the Nambucca River and door knocked homes overnight.

Some 630 callouts were received by the SES in the 24 hours up to 6am Thursday, with 27 flood rescues, predominantly from vehicles.

Many of the calls for help were for sandbagging to protect against flooding and for damaged roofs.

The Northern Rivers, Mid North Coast and Central Coast are the areas of concern for the SES on Friday.

The wet weather is set to continue for months, with BOM advising autumn is likely to be warmer and wetter than usual in most parts of the country.

This includes areas already hit by floods over summer.

The La Nina oscillation is also expected to end sometime in autumn and has already showed signs of waning, the bureau says.

Some small parts of eastern NSW may have a cooler than usual autumn, but across Australia night time temperatures are expected to be higher than average.

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