South-east Queensland is on alert for flash flooding this morning as inundated communities in New South Wales shift to recovery mode.
The weather bureau for heavy rainfall in Queensland's south-east coast, Wide Bay and Burnett and far southern Capricornia districts.
It says 24-hour rainfall totals of up to 200mm are likely, with locally heavier totals in some areas.
The Bureau of Meteorology says a combination of an upper level low and surface trough near the south-east coast is causing the instability.
Senior forecaster Jonty Hall says the activity will bring major downpours and flash flooding over the next three days and there could be falls of between 200 and 300 millimetres in parts.
"South of about the Fraser Island area is where we expect to see the heaviest falls for the next 24 hours or so, pretty much from Fraser down to the New South Wales border and inland to the ranges," he said.
However he says the conditions will not be anything like Oswald.
"It is likely to be raining fairly continuously throughout that period, but the heavier falls will come in bursts on and off so it won't be particularly raining the whole time," he said.
"We could have the odd rumble of thunder with the heaviest stuff coming through, but thunderstorms aren't likely to be a big feature of this event."
Swollen creeks and rivers are starting to recede in New South Wales, but around 20,000 people are likely to remain isolated for several days.
Flooding in the Hastings River has eased, and residents in Port Macquarie and Settlement Point were last night given the all-clear to return home.
The State Emergency Service says the evacuation order still in place for Kempsey will be lifted once the Macleay River drops to a safe level.
Phil Campbell from the State Emergency Service says volunteers will be using floodboats and helicopters to help people who are stranded.
"The focus for the SES is now on recovery and resupply of those people who are still isolated by floodwater," he said.
Meanwhile, around 1,000 homes are still without power in parts of Sydney and the central coast after a destructive storm battered the region at the weekend.
The SES received more than 2,000 calls for help, mainly for homes damaged by galeforce winds in Sydney's southern suburbs and at Kiama on the south coast.