Update: Wild weather has hit the South West, with a Bunbury pub losing part of its roof in the high winds.
SES personnel were called to the Victoria Street building around 11.30am today to help stabilise the structure.
“The building lost a number of roof sheets, and part of the street has been blocked,” a DFES spokesman said.
Wind also blew down part of a fence housing ponies from the Gypsy Circus in Langley Park this afternoon.
Three of the animals had to be cajoled back into the enclosure by staff members with food.
There have also been reports of a tree crashing through the roof of a home in Medina.
About 26,000 customers in the metropolitan area and the South West lost power.
Simon Bailey from Western Power told ABC radio the worst hit areas are South Perth, Victoria Park, Swan View and Como.
Lightning strikes and trees falling on power lines have been blamed for the outages.
There is likely to be havoc on the roads this afternoon as traffic lights across the metropolitan area are blacked out.
About 10.45am a car towing a caravan jack-knifed on Roe Highway eastbound near Welshpool Road. Weather conditions were windy at the time but no one was hurt.
Emergency services have answered more than 22 calls for help.
Damage has been reported in Margaret River, Bunbury and throughout the metropolitan area.
As at 4.46pm the Bureau of Meteorology advised that a strong cold front was moving through eastern parts of the South West Land Division and into the south-west Goldfields.
A severe weather warning has been issued for people in parts of WA bounded by a line from Hopetoun to Wongan Hills to Mount Jackson to Israelite Bay and the south coast. This includes people in, near or between Southern Cross and Esperance.
The warning for parts of WA south-west of a line from Badgingarra to Dalwallinu to Wongan Hills to Hopetoun - including the Perth Metropolitan Area - has now been cancelled.
The front is expected to be windier than a typical front and is likely to produce the kind of weather that is only seen once or twice a year.
Damaging winds of up to 125km/h could hit some areas.
A wind gust to 111km/h was recorded at Cape Leeuwin at 6.30am, a gust to 104km/h was recorded at Cape Naturaliste at 10am and Rottnest Island recorded a gust of 106km/h just after 1pm.
Hail and localised flooding is also possible.
The bad weather comes in the wake of a wet weekend, with Worsley Downs, east of Bunbury, hit by 72mm of rain and Pemberton 59mm over the past 24 hours.
Wind gusts of 120kmh were also recorded on Rottnest, but only 1.2mm of rain fell in Perth.
Fallen power lines should be reported. Make the Safe call to Western Power on 13 13 51.