Gusty showers, storms and a huge swell will hit Perth and the south-west of the state over the weekend as three cold fronts approach Western Australia in rapid succession.
The Bureau of Meteorology said the first front, which will move through on Friday night and Saturday morning, will bring the most rain.
Thunderstorms and gusty winds could develop with the second front, which will arrive on Saturday evening and early Sunday, and the third storm cell which will cross the coast on Sunday.
Senior meteorologist Steph Bond said this kind of quickfire winter storm activity occurred about once a year.
"For Perth, we're probably looking at around 25 to 35 millimetres (of rain) over the weekend period," Ms Bond said.
"We expect the west coast, south of Jurien Bay to have the most rain, similar totals to Perth."
Ms Bond said isolated falls of between 50mm and 80mm are possible over coastal areas but showers will be lighter in agricultural areas.
"For the Great Southern, we're probably looking at 10 to 20 millimetres over the weekend. Unfortunately for the Central Wheatbelt, we're probably only looking at around 5 to 10 millimetres over the weekend," she said.
Powerful swell forecast
Dangerous surf conditions are on the cards for Perth and the South West due to a strong swell.
Ms Bond said the swell in Perth could be between three and six metres on Sunday, but said further south it will be even bigger.
"By Sunday morning, along the South West Capes we're looking at swells of around five to six metres and they're just going to increase during Sunday ... we're looking at swells [of] up around 8 metres to come through Sunday evening and on Monday," she said.
"When we have cold fronts moving through numerous times and we get the wind in the same direction for days on end, that helps generate these big swells."
However, the westerly wind direction means surfers aren't likely to have much joy except in sheltered beaches.
In Perth gusts of up to 55 kph are possible over the weekend but gusts could reach up to 110 kph with showers and storms south-west of a line Mandurah to Albany.
There is no reprieve from the rain in sight, with showers forecast every day for the next week in the metropolitan area and much of the south-west.