Severe weather in NSW is expected to intensify, with coastal regions facing destructive wind and flash flooding, state Emergency Services Minister Jihad Dib says.

“We have got a rain and a wind combination ... and the situation will deteriorate over the next 24 hours, particularly later this afternoon through to the evening,” he told a briefing today.

Emergency workers were doorknocking in some communities and the state government has pre-deployed personnel, high-clearance vehicles and aerial resources.

The worst conditions are south of the Taree region, which was hit hard by riverine flooding in May. This week’s large and complex system is different to conditions that brought the previous severe weather, Mr Dib says.

“What we will see in the next 24 hours is rain but also very strong winds.”

The State Emergency Service says it has already responded to more than 900 incidents, mostly in the Central Coast and Newcastle regions but with calls for help increasing through Sydney and the Illawarra this afternoon.

Jarvis Bay had received more than 150mm of rain in the 24 hours to 2.30pm today.

The Bureau of Meteorology has warned of wind above 90km/h from southern Queensland to the NSW South Coast and says damaging gusts of more than 125km/h are possible around Sydney’s eastern suburbs and south along the coastal fringe.

“With those winds, we could see significant damage to trees and property,” meteorologist Jonathan How said this afternoon.

A low-pressure system is expected to draw “very vigorous winds” onto the coast, plus widespread rain, and the bureau warns of potential flooding in several catchments from tonight.

The Upper Nepean and the Hawkesbury and Lower Nepean rivers could be affected by minor to moderate flooding, while minor flooding is possible for rivers including the Cooks and Shoalhaven. Hazardous coastal conditions are expected from the Hunter region south.

“Later Wednesday, we see another low-pressure system really dumb-belling around that first one and that will really intensify and reinforce some of those winds and rain across the south coast in NSW,” Mr How said. “It’s not until late Thursday that we finally see the conditions easing up.”

The heaviest rainfall is forecast south of Wollongong, with totals by Thursday night potentially exceeding 200mm.

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