Flood recovery centres and assistance points have opened in communities across NSW as the state again braces for intense storms and possible flash flooding.
The 27 centres, operated by Resilience NSW, provide support for people and their families as well as farmers and business owners helping them access government support and services.
People can access accommodation at the centres, have lost documents replaced, and access mental health, business, financial, insurance and legal support.
"The trauma our flood-affected communities right across the state continue to suffer is immense," Flood Recovery Minister Steph Cooke said Monday.
"This is why we are doing everything possible to help residents kickstart their recovery journey."
Of the recovery centres and assistance points opened, there are 14 in the Northern Rivers, four in the Hawkesbury-Nepean Valley, three on the Central Coast, two on the South Coast, two in the Hunter and one in the Southern Highlands
It comes as heavy rainfall with a risk of possible life-threatening flash flooding is predicted for the Northern Rivers, North Coast and Northern Tablelands on Monday and through to Tuesday, Bureau of Meteorology senior meteorologist Jonathan How told AAP.
Falls of between 30mm and 60mm were recorded from Tweed Heads to Byron Bay overnight, adding to 100mm and 200mm recorded over Saturday and Sunday, Mr How said.
Heavy falls moving from the Queensland border would "really peak (Monday) afternoon and into the evening".
The rain will continue into Tuesday and only begin to ease that afternoon and evening.
The forecast zone includes Tweed Heads, Murwillumbah, Byron Bay, Lismore, Yamba, Grafton, Coffs Harbour and Dorrigo, where six-hourly rainfall totals of between 80 and 140mm are predicted.
"All of those locations could see those really heavy falls, but it does come with a caveat that those flows will be with the thunderstorms, Mr How said.
He stressed while the conditions were similar to those in the recent Lismore flood, the outcome was not predicted to be as widespread and severe.
Lismore's mayor Steve Krieg said the next two days would be critical for how Lismore is going to fare over the next week.
"It won't bloody stop raining up here," told the Nine Network on Monday.
"This is a major development, this weather front. If our river rises, we're going to start the evacuations today just to be cautious."
Rough seas are expected along the Byron Coast on Tuesday, and dangerous swells will also hit shores on the Macquarie and Hunter Coast on Wednesday.
A flood watch is in place for the Northern Rivers, Mid North Coast, Hunter, Hawkesbury Nepean and North Western NSW Rivers.
Moderate to major floods are possible on the Richmond, Wilsons, Orara and Bellinger Rivers from Tuesday as heavy falls hit already-saturated catchments.
Minor to moderate flooding is also a risk for parts of the Northern Rivers, the North Coast, Hunter, Hawkesbury-Nepean and North-Western NSW rivers.
© AAP 2022