Destructive winds of more than 200km/hr have uprooted trees and lifted roofs as Cyclone Damien crossed the West Australian Pilbara coast where thousands of people have been in lockdown.
The category three severe tropical cyclone made landfall near Dampier late Saturday, bringing fierce gales to the industrial port and the nearby city of Karratha before weakening.
From the Pilbara to Paddington, NSW, torrential downpours have been dousing bushfires, soaking parched pastures and turning formerly dry watercourses into torrents while adding to the pressures on emergency officials.
Heavy rain is expected to cause flooding in WA's Pilbara and Gascoyne regions, with falls of up to 300mm or more possible in some areas.
It drew swift condemnation from NSW Police minister David Elliott, who labelled the driver a "boofhead" and asked police to investigate.
BOM says the trough bringing persistent rain and windy conditions will continue extending into the southern coast on Sunday.
Damaging wind gusts exceeding 90km/h are possible along the coastal fringe between Ulladulla and Forster, and damaging surf conditions are forecast to develop on Saturday night or Sunday.
BOM also warned that the burned-out landscape and loss of vegetation on the fire-affected South Coast had left it vulnerable to landslips.
There were 38 fires still burning throughout the state on Saturday evening.