Dozens of people are stranded on roofs and towns have been inundated amid major flooding in NSW – with worse on the way.

NSW Emergency Services Minister Jihad Dib said 284 people had been rescued in the past 24 hours, including 150 since midnight.

“We have seen an enormous amount of rainfall over the Hunter and mid-north coast area,” he said.

More than 1600 SES volunteers are on the ground, with 20 multiagency flood rescue teams. The Defence Force has also responded to a request for assistance.

“What we’re seeing is a clear example of throwing every single thing we have at this event,” Dib said.

SES spokesperson Andrew Edmunds said 52 people were believed to be trapped by floodwaters at Glenthorne.

“As soon as we are safely able to do so we will be getting to those people and helping them to safety,” he told the ABC.

Jordan Halloran was among those stranded in Glenthorne. She, her husband Sam and their two-year-old son were stuck on the upper level of their home on Wednesday, with water just 600 millimetres below.

“We are awaiting a rescue and we have been waiting since 1am,” she told ABC TV.

“They said the only way to get us out at the moment is with a chopper and there aren’t any.

“We have seven neighbours next door. There is people from the street that are all in that house, that is about to go under water. If there is anything at all that can be done to support, that would be great.”

Later on Wednesday, Sam Halloran posted a video of the family’s rescue to Facebook.

“We are now all out and safe, including our two doggos. Can’t thank everyone enough for your kind words and efforts to help us,” he wrote.

“Huge thanks to NSW police rescue and the SES for getting us out safely.”

Edmunds said “around 16,000 people” or 7400 dwellings would be isolated for at least a day due to water levels.

SES Zone Commander Andrew Cribb said the real focus was on what is to come.

“Throughout the Hastings and Maclean and Nambucca catchments, we need the residence of those areas to listen to the warnings,” he said.

“We will be escalating the warnings at the appropriate times in those areas.

“We are expecting severe thunderstorms or intense rainfall at times and the issue is that will occur tonight.

“We do not want people to be leaving their homes at night, so make your decision now.”

Downpours continued on much of the NSW mid-north coast on Wednesday as the coastal trough slowly tracks north.

By the afternoon, evacuations were ordered at Gloucester, the Kempsey CBD and Smithtown.

Coffs Harbour, Port Macquarie, Taree, Kempsey, Sawtell, Dorrigo, Barrington Tops, Wingham and Yarrowitch are also in line for more rain as rivers continue to rise.

On Tuesday night, locals near the Manning River were warned to evacuate as the river surged past major flooding levels.

It peaked at Taree at a record 6.3 metres on Wednesday – a level “never seen before”, surpassing the 1929 record of six metres, the NSW State Emergency Service said.

Taree has had a third of its average annual rainfall in the past two days.

The weather bureau’s hazard preparedness manager, Steven Bernasconi, said there had also been record May rainfall at nearby Wingham (278 millimetres in a day) and Campsie (120 millimetres).

“[Wingham] is likely to break its two-day record as well, once more data comes in from this morning,” he said.

“This is significant rainfall falling over already saturated catchments, which is leading to and led to floods of record, particularly for Taree today.”

Publican Robyn Hawkins from Taree’s Wynter Tavern loaned the venue’s courtesy bus to the emergency services.

“I’ve given the bus to SES volunteers to evacuate a nursing home, so they can take the elderly people to higher ground,” she said.

“Everyone knows us here and we’re still operating as normal – I’m trying to make some wraps so we can feed the SES.

“[The flood] is devastating for a lot of people in the community.”

More than 80 warnings were in place late on Wednesday morning after falls of up to 280 millimetres in some areas.

Up to 300 millimetres more rain is expected in the next two days on the Coffs Coast and northern tablelands.

Some northern catchments are already saturated after being hit by Cyclone Alfred in March.

“What we had 24 hours ago was in the Hunter area, then the mid-north coast and is slowly moving into the north-east,” NSW SES Commissioner Mike Wassing said.

A stay-indoors message was issued for elevated inland parts of the mid-north coast, including Bowraville and the outskirts of Coffs Harbour.

Six-hourly rainfall totals 100-140 millimetres were possible through the day, the SES said.

-with AAP