Heavy falls hit northern Queensland after a brief reprieve, with coastal and inland centres including Townsville, Cardwell and Ingham in the firing line.
Major flood warnings are in place for the Herbert, Burdekin, Haughton, Flinders, Cape and the Western Rivers, with minor-to-moderate warnings in place for a number of other catchments through north east and northern inland Queensland.
Bureau of Meteorology senior meteorologist Myriam Bradbury said 24-hour rainfall totals could reach up to 250mm.
"This rain is falling onto saturated land, meaning it will quickly run off and top up already swollen rivers," she said.
"This means that even moderate rainfall totals could cause swift river rises and could lead to dangerous flooding conditions."
The flood warnings come as communities in northern Western Australia remain on watch for a possible tropical cyclone.
A tropical low is expected to move along the Kimberley coast on Sunday, whipping up damaging gusts of up to 100km/h.
The low could reach tropical cyclone intensity late on Sunday or early Monday as it heads towards Broome and the Pilbara, bringing widespread falls.
Ms Bradbury said gales could develop as early as Monday morning with increased rain and large waves from late Sunday.
"Forecast rainfall in the flood watch area is expected to result in river rises, areas of flooding and may adversely affect road conditions," she said.
"Roads may quickly become impassable and some communities may become isolated once that rain starts to fall."
Heavy rain in Queensland in the past week forced hundreds of people to evacuate their homes and left communities without power.
A major bridge in the town of Ingham was washed away, with the Australian Defence Force called in to restore temporary for crucial supplies.
Some residents have started to return to flood-ravaged homes, with more than 4000 storm and flood-related insurance claims so far.
The total damage bill is unknown.
So far $8 million is available for affected residents through the Commonwealth's community relief fund while Queensland Premier David Crisafulli is pushing for federal support to lift bridges above flood level along the Bruce Highway.
Queensland Reconstruction Authority chief executive Jake Ellwood warned the clean-up would be hard, with an enormous toll on the mental health of affected people expected in addition to physical and economic impacts.
"Recovery and reconstruction is not a days and weeks event - it is months and years," the retired Major General told reporters in Townsville.