Intersections and low-lying areas were awash on Wednesday as the storms lashed Perth and dozens of towns in the state's southwest.
More than 70mm of rain fell in the coastal holiday town of Busselton, with Jarrahwood and Pemberton recording 56mm and 50mm since 9am respectively.
In Perth, social media sites were full of images and videos of homes with roof tiles ripped off, flooded streets, vehicles stuck in water and fallen fences.
About 15,000 homes and businesses lost power as the intense winds brought down trees and powerlines across the state's south, with most still cut off late in the day.
Rottnest and Garden islands recorded wind gusts of more than 110km/h, with Perth airport and Swanbourne hit by 93km/h and 91km/h gusts.
Emergency services were kept busy, with more than 180 calls for help as water inundated dozens of homes and trees and debris fell across roads.
WA Police was also affected, with Kwinana police station forced to shut after a power outage.
"The station is closed to the public but our officers are still out responding to calls from the community," the station tweeted.
A severe weather warning remains in place as the massive cold front stretching more than 1000km from Kalbarri to Esperance and the inland goldfields moves east.
The Bureau of Meteorology said destructive winds and bursts of heavy rainfall, with gusts of more than 125km/h, are possible in the Wheatbelt, Goldfields and Gascoyne regions.
The damaging wind risk will gradually clear from the west and ease below severe thresholds towards midnight.
Communities that may be affected include Albany, Esperance, Kalgoorlie, Katanning, Merredin, Mount Barker, Mount Magnet and Norseman.
An earlier thunderstorm warning has been cancelled.
