A severe weather warning has been issued for residents between Mandurah and Walpole.
The cold front is expected to reach the Capes early this afternoon and extend eastwards along the south coast late afternoon and evening.
Thunderstorms are also possible.
Higher than normal tides may result in flooding of low-lying coastal areas inthe Geographe Bay area, including Busselton and Dunsborough, on Tuesday morning.
Conditions will ease this evening.
A Weather Bureau spokesman said widespread damaging winds with locally destructive gusts and abnormally high tides were expected to start moving across the area this morning.
The warning includes people around Bunbury, Busselton, Margaret River and Bridgetown.
"A cold front during Tuesday is likely to cause widespread damaging winds to 100km/h that could result in damage to homes and property," the Bureau says.
"In isolated areas dangerous gusts in excess of 125km/h could cause significant damage or destruction to homes and property."