A woman is still missing after being swept away by floodwaters in the Hunter Valley while about 20,000 properties are without power after a weekend of wild weather across parts of NSW.

The 26-year-old was swept away on Saturday evening after escaping a car that became stuck when it was driven into floodwater at Rothbury, near Cessnock.

NSW Police said a multi-agency search was suspended yesterday due to severe weather conditions and poor visibility, but the search resumed this morning. 

The SES said it received more than 3,600 calls for help across the state since the start of the severe weather event on Saturday, with its crews responding to 2,092 jobs.

SES crews work to remove a fallen tree from a road in the dark.

The SES has responded to more than 2,000 incidents, including this fallen tree near Wyong, on the Central Coast. (Supplied: SES Wyong)

There were 25 flood rescues included in those jobs.

Four flood emergency warnings are in place: one in the Hunter region for parts of Raymond Terrace; and three for different areas of Gunnedah in the state’s north west.

The SES has issued 15 watch and act warnings across the wider Hunter region and New England and north-west areas.

SES Northern Zone Deputy Commander Superintendent Ian Robinson said an evacuation order for some homes at Raymond Terrace would likely remain in place “for a while yet”, as parts of the Hunter River continued to rise upstream.

“We’ve got a bit of a focal point up around the Singleton area … we’ve issued three prepare to evacuate warnings this morning very early,” he told ABC Newcastle Breakfast.

“It’s not imminent, but we’re expecting the flood water there to reach around about 12.5 metres which is quite significant … that is under the major flood level, but it’s certainly over the minor and into the moderate.”

Superintendent Robinson said the flood water would eventually come down the Hunter through Maitland and also affect Raymond Terrace, so the evacuation order would “stay in place for the time being”.

Snow on trees and powerlines.

Snow caused localised power outages over the weekend. (Supplied: Essential Energy)

In the state’s north west and northern tablelands, towns like Uralla were peppered by snow over the weekend, leading to power outages and road closures.

SES North West Command Acting Chief Superintendent Stuart Fisher said about 500 people were affected by evacuation orders in the emergency warning areas of Gunnedah.

“We do have an evacuation centre open up for those who wish to go, and that’s at the PCYC in Gunnedah,” he told ABC New England North West Breakfast.

Acting Chief Superintendent Fisher said the Namoi River at Gunnedah was at about 8.2 metres on Monday morning, at major flood level.

“There’s a whole heap of water behind that coming out of the Keepit Dam and working its way through Tamworth and down, and we’re just watching to see what that does,” he said.

“We’ve had two flood rescues overnight for three or four people stuck in flood water, so people are persistently still trying to get through flooded water.

“Again, it’s the same message we give every time, do not enter flood waters.”

power pole down across white house surrounded by green fields.

More than 20,000 people across NSW remain without power after a weekend of wild weather. (Supplied: Essential Energy)

Power provider Essential Energy has reported more than 21,000 homes were impacted by power outages on Sunday evening, with most outages continuing into this morning.

Most of the outages were at Kempsey, South West Rocks and Smithtown on the Mid North Coast, with more than 10,000 properties impacted.

Armidale, Walcha, Guyra, Bendemeer and surrounds had more than 8,200 properties without power, while 3,000 were without power at Smiths Lake, Pacific Palms, Coomba Park and surrounds.