A weather warning has been issued in the Northern Territory as monsoon rains threaten to bring flash floods, while parts of Western Australia also cop a severe storm warning.
Heavy rains that could lead to flash flooding are expected in the territory's central districts on Saturday afternoon, the BOM says.
It warned that the town of Tennant Creek lies within the area that could be affected.
A monsoon trough lies across the mideast of the territory and a weak monsoon low is affecting the Barkly region, east of Tennant Creek, in the territory's central region.
The thunderstorms are slowly moving north, BOM satellites indicate.
The bureau says people should stay indoors, secure their property and avoid driving.
In Western Australia, residents in the central west and lower west regions have also been urged to "take action and stay safe" as severe thunderstorms approach.
Storm cells and damaging winds are predicted for parts of the Midwest-Gascoyne, Goldfields-Midlands and Perth Metropolitan areas.
The areas in the warning zone include Moora, Northam, Dalwallinu, Dowerin, Morawa, Paynes Find, Toodyay, Wongan Hills and York.
People are urged to find shelter away from trees, powerlines, storm drains and streams.
People should also unplug appliances and avoid using landlines if there is lightning.
The storm is being generated by a trough along the west coast, generating gusty thunderstorms, the BOM said.
The storms in WA are moving inland.
