The Bureau of Meteorology warns that a trough moving across NSW could prolong the flooding, with widespread showers and thunderstorms predicted across much of the state, especially on Tuesday.
Communities are bracing for more destructive rain as the BOM issued minor to major flood warnings in a number of catchments that are already saturated.
The weather forecaster on Monday afternoon warned the low pressure system may also move over the southern coast on Wednesday.
"Heavy rainfall and strong winds are possible somewhere along the southern half of the coast, but there's some uncertainty for the exact location," it said on Twitter.
In the state's north, the towns of Warren and Wee Waa remain cut off and expected to remain isolated for days as the flood emergency continues.
Further east, the town of Gunnedah continues to be affected by flooding but the water is slowly receding.
The Namoi River, which runs through Gunnedah, peaked at of 8.24 metres at the weekend. SES workers are assessing the damage.
The crisis has claimed the life of a five-year-old boy who was found dead on Saturday afternoon after the vehicle he was in got swept away at Tullamore, near Parkes.
Emergency services received hundreds of calls for help since the flooding hit the region last week.
SES Assistant Commissioner Nicole Hogan said Central West and North West regions remained at risk of further flooding during the next six to eight weeks.
With more rain forecast this week, Ms Hogan said it was crucial that residents and those travelling in the region took care.
"We are asking people, particularly with the school holidays, to prepare their route, (and) know where they're going ahead of time ... and if they are camping on the side of a river, to really be aware of their surroundings," she told ABC television on Monday.
"Communities just really need to understand their flood risk, know what the conditions are like, be aware of their surroundings."
On the north coast at Lismore, which was devastated by floods earlier this year, Labor leader Chris Minns said the key message from the community was that promised support had to hit the ground.
Lismore was submerged in record-breaking floods in February and March and came under threat again last week from saturated catchments.
"The funds need to come, if they don't come you'll start to see businesses shut their doors and they won't return," Mr Minns said.
