Update, 11.10pm: Heavy rain and strong winds caused havoc tonight, with theatregoers being turned away from the Perth premiere of West End production A Clockwork Orange after the severe weather knocked out power at the Subiaco Arts Centre.
And Wanneroo Road was closed in Ashby when trees felled power lines.
Residents across the southern half of the State were braced tonight for severe weather and possible property damage after being inundated with up to 100mm of falls and strong winds.
Perth had 53.4mm of rain in the 24 hours to 4.30pm on Wednesday, while parts of Busselton were hit with more than 88mm. Margaret River had almost 60mm and Rottnest Island 67.4mm.
A Weather Bureau monitoring station at Aston Downs, south of Busselton, recorded more than 100mm to 9am. Winds of more than 100km/h were recorded at Garden and Rottnest islands.
The heavy rain and strong winds were forecast to continue overnight over most of southern WA, with possible severe weather continuing into Wednesday morning.
Update, 3.25pm: The Bureau of Meteorology says a deep low will pass to the south of the State, resulting in damaging winds up to 100km/h.
A weather warning has been issued for people for people south-west of a line from Lancelin to York to Hopetown The warning includes people in the Perth metropolitan area and those in Busselton, Bubnury, Mandurah, Albany, Bridgetown, Margaret River, Narrogin, Katanning and York.
The Bureau says the gusts for the rest of today and tomorrow morning could result in damage to homes.
The storm is expected to hit isolated areas west of a line from Lancelin to York to Windy Harbour today and move south of a line from Busselton to Katanning to Bremer Bay early tomorrow.
Wind gusts of 106 km/h have been reported from Rottnest at 1pm, 100km/h at Garden Island at 12.30pm and 94km/h from Ocean Reef at 1.30pm.
In Jandakot, 13.4mm of rain has been recorded since 9am. Bickley has recorded 13mm of rainfall since 9am.
People in an area bounded by Paraburdoo to Carnegie to the South Australia border and along the south coast to Hopetoun to Menzies to Meekatharra to Paraburdoo are being warned of "intense" thunderstorms and showers.
A severe weather warning includes people in or near Meekatharra, Kalgoorlie, Esperance and Eucla.
The Bureau says a strong cold front is between Paraburdoo, Meekatharra and Hopetoun and is expected to move to Newman to Carnegie to Eyre by tomorrow morning.
A wind gust to 89 kilometres per hour was reported from Esperance at 2.15 pm.
1.50pm: A water main has burst on Mounts Bay Road, closing the westbound carriageway near Kings Park Avenue.
Watercorp workers are at the scene in Crawley, directing traffic and trying to fix the pipe, which burst just before midday.
A Main Road spokeswoman said "contraflow" was in place, meaning the eastbound carriageway was carrying traffic in both directions.
“Repair works will be going through afternoon peak hour,” she said.
“The road can’t be repaired when it’s raining so the repair works are going to be subject to weather conditions.
“Avoid the area this afternoon if you have the option.”
Minor flooding has been seen in low-lying areas surrounding the river, but no serious damage has been reported.
Wind speeds continue to intensify across the south-west, with Ocean Reef recently recording wind gusts in excess of 80kmh.
Meanwhile in cyberspace, the Twitter hashtag #Perthstorm has started trending ahead of tonight’s anticipated wild weather.
11am: Perth commuters have – eventually - made it through a wet and wild morning on the roads relatively unscathed.
The State Emergency Service has answered more than 52 calls for help after a cold front hit Perth and the South West overnight.
Despite minor flooding, poor light and steady rain, there had been no major crashes in the metropolitan area as at 10:30am.
However, a Main Roads spokeswoman said peak-hour congestion was still evident in some areas, because of both the conditions and the notice given to commuters yesterday.
“The Kwinana Freeway northbound is still heavy from Manning Road all the way in,” she said.
“The Mitchell Freeway usually clears by 8am or 9am, but right now it’s still heavy from Hepburn Avenue and then again from Cedric Street to Vincent Street.
“More people choose to drive when they’ve been warned about the weather, so we definitely see a change in traffic volumes.”
Roads such as Tonkin Highway, Guildford Road, Walcott Street, Wanneroo Road and Loftus Street were more congested than usual this morning.
The spokeswoman said there had been minor flooding across Perth and reminded motorists to take care on roads partially submerged in water.
“There’s still residual flooding. The flooding is still there on South Street eastbound, Bannister Road in Canning Vale, Armadale Road westbound in Haynes, Morley Drive westbound in Yokine and the Graham Farmer Freeway at the Loftus Street entry ramp.
"That flooding also affected the cyclist path, which was a bit of a problem for them.”
By 10.30am, the deep low to the south of the state had started generating stronger winds across the South-West.
Many centres from Geraldton south recorded wind gusts in excess of 50kmh this morning.
7.40am: The State Emergency Service answered 37 calls for help as heavy rain soaked Perth and parts of the South-West overnight but the worst is forecast to come today and tomorrow.
In the last 24 hours, some of the highest rainfalls recorded were at Cape Leeuwin (59.8mm), Busselton (57.2mm) and Swanbourne (55.6mm).
Cunderdin and Mandurah recorded wind gusts of 87kmh and 81kmh respectively, while Mount Magnet had winds in excess of 50kmh.
As is often the case, Rottnest Island bore the brunt of the weather, recording wins gusts of 91kmh and 61.4mm of rain.
A Department of Fire and Emergency Services spokesman said the 37 overnight emergency call-outs were largely related to water damage and leaks.
“We had one where the internal lining of the roof collapsed due to the volume of water coming in,” he said.
“I’m sure the guys will be tarping a few of those roofs up this morning.
“It was mainly just people who hadn’t prepared their houses for the rain.”
He said the weather developing day had more potential to cause headaches.
“The wind is usually the one that can cause the damage,” he said.
“Once we start getting strong winds then we start getting impacts from trees and structural damage.”
Strong winds are expected to develop across the south-west today as a deep low passes to the south of the state.
The Bureau of Meteorology warned the low could generate squally conditions, with wind gusts in excess of 125kmh and potential flooding in low lying, coastal areas.
The long cold front that crossed the WA coast late last night – a separate system - brought rain from Exmouth to Esperance.
That front is expected to produce stormy weather as it continues moving inland today over parts of the Gascoyne, Goldfields, Eucla and the Wheatbelt.
Sheep Graziers in the Wheabelt and South-West have been warned that cold temperatures, showers and strong northwesterly winds could lead to animal deaths without precautions.
5.40am: The State Emergency Service has answered 37 calls for help after a cold front hit Perth and the South West overnight.
The SES received 31 calls for assistance in the metropolitan area and six in the South West. The majority of the calls related to water damage.
A spokeswoman for the Department of Fire and Emergency Services said the number of calls for help was likely to increase as people woke to the effects of the storm.
"People are being urged to do what they can to help themselves, if it is safe to do so, before calling the SES for assistance," she said.
More bad weather coming from Perth to Corrigin to Lake Grace to Bremer Bay
If you live south west of a line from Perth to Corrigin to Lake Grace to Bremer Bay you should take action and stay safe with more bad weather to come.
This includes people in, near and between Augusta, Busselton, Bunbury, Mandurah, the Perth metropolitan area, Albany, Bridgetown, Margaret River, Narrogin and Katanning and surrounding areas.
DFES warns residents from GGascoyne Junction to Paraburdoo to Carnegie to Balladonia and along the coast to Bremer Bay to Lake Grace to Paynes Find to Gascoyne Junction to take action and stay safe with the start of dangerous weather.
This includes people in, near or between Meekatharra, Newman, Southern Cross, Kalgoorlie and Esperance.
Wednesday, 4am: A severe weather warning remains for WA, with the Weather Bureau forecasting destructive winds, abnormally high tides and damaging surf for people in the Lower West, South West, South Coastal and Great Southern forecast districts.
The bureau says the passage of the deep low on today and tomorrow is likely to produce the kind of weather that is only seen once or twice a year.
The worst is expected between Bunbury and Bremer Bay.
In a report issued at 3.43am the bureau warned people in parts of the south-west of a line from Perth to Corrigin to Lake Grace to Bremer Bay. This includes people in, near or between the following towns: Augusta, Busselton, Bunbury, Mandurah, the Perth metropolitan area, Albany, Bridgetown, Margaret River, Narrogin and Katanning.
During Wednesday and Thursday a deep low will pass to the south of the state.
Strong and squally winds are expected within the warning area.
From Wednesday night the passage of the low is likely to cause damaging winds to 100km/hthat could result in damage to homes and property.
In isolated areas dangerous gusts over 125km/h could cause significant damage or destruction to homes and property
Abnormally high tides which may cause sea water flooding of low lying areas are forecast for the Lower West forecast district and South West forecast districts.
Dangerous surf conditions are likely which could cause significant beach erosion from tonight.
Tuesday, 11.30pm: The Weather Bureau has issued a severe weather alert for parts of southwest WA, warning of destructive winds and abnormally high tides.
The bureau warned people in parts of the State of a line from Geraldton to Northam to Walpole contracting to south of a line from Perth to Corrigin to Lake Grace to Bremer Bay.
This includes people in, near or between the following towns: Jurien Bay, Augusta, Busselton, Bunbury, Mandurah, the Perth metropolitan area, Albany, Bridgetown, Margaret River, Narrogin and Katanning but not including Northam or the Central Wheatbelt.
During Wednesday and Thursday a deep low will pass to the south of the State.
The passage of the strong cold front Tuesday evening and early Wednesday morning may cause localised dangerous gusts in excess of 125km/hour that could cause significant damage or destruction to homes and property.
Thunderstorms and moderate to heavy falls are also possible. During Wednesday
strong and squally winds are expected within the warning area. From Wednesday night the passage of the low is likely to cause damaging winds to 100km/h.
The worst of the weather is expected to be south of a line from Bunbury to Bremer Bay.
Abnormally high tides which may cause sea water flooding of low lying areas are forecast for the Lower West forecast district and parts of the Central West and South West forecast districts.
4.20pm: Severe weather warning for destructive winds and abnormally high tides has been issued for people in the Central West, Lower West, South West, South Coastal and Great Southern forecast districts.
A strong cold front will move over the region Tuesday evening and early Wednesday morning. During Wednesday and Thursday a deep low will pass to the south of the State.
Thunderstorms and moderate to heavy falls are also possible. During Wednesday strong and squally winds are expected within the warning area.
From Wednesday night the passage of the low is likely to cause damaging winds to 100km/h.
The worst of the weather is expected to be south of a line from Bunbury to Bremer Bay.
The passage of the deep low on Wednesday and Thursday is likely to produce the kind of weather that is only seen once or twice a year.
12.30pm: West Australians are being reminded to prepare for the potentially destructive weather expected to hit the coastline later this afternoon.
While the stormy conditions were yet to reach WA at noon, a Bureau of Meteorology spokesman said they were on their way.
“Showers will develop late this afternoon and into the evening, ahead of the front,” a bureau spokesman said.
“The front itself will cross sometime between midnight and 3am. We won’t really see winds pick up until midnight.
“The front extends all the way up the coast. We expect reasonable falls all along the coast and some locally destructive winds.”
Very little rain had fallen across the State by noon, but winds were starting to reach speeds in excess of 40kmh in the South West.