Heavy rainfall is expected to lash the Tanami, Lasseter and Simpson districts on Sunday, with the Bureau of Meteorology warning flash flooding is likely.
Up to 140 millimetres could fall in the state's southwest before the rain eases off on Sunday afternoon.
Meanwhile, West Australian authorities and the Australian Defence Force are supporting towns in the Kimberley region after rain from the ex-cyclone caused the Fitzroy River to break its banks.
The remote town of Fitzroy Crossing and the tiny Indigenous community of Noonkanbah were devastated after the river last week reached a record peak of 15.81 metres.
The rain cleared on Saturday, making it once again safe to open the Fitzroy Crossing airport.
That allowed authorities to deliver 3000 kilograms of food, medicine and other supplies to the cut-off region.
More than 100 residents have already been evacuated from the Kimberley, but more may be relocated in the coming days as flooding continues in the towns of Looma and Willare.
WA Emergency Services Minister Stephen Dawson spoke to locals at Fitzroy Crossing on Saturday afternoon and thanked the community for their resilience.
"Nothing like this has ever been experienced in Western Australia before," he told reporters on Saturday.
"To their great credit, they've been patient and they've persevered."
On the other side of the country, residents in NSW's far west are being warned the Darling River is yet to peak.
The town of Menindee has already been inundated but the river could rise to more than 10.7 metres in the coming days, which is higher than the 1976 record.
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