Residents between Mandurah and Walpole are being warned to prepare for rough weather.
The Bureau of Meteorology says a cold front moving over the area this morning could see damaging winds of up to 125 kilometres an hour.
Thunderstorms are also possible.
The warning includes Mandurah, Bunbury, Busselton, Margaret River, Bridgetown and surrounding areas.
© ABC 2012
18:25 EST Rain is on the way for the North West Slopes and Plains and the Northern Tablelands.