Record-breaking rainfall south of Perth has caught thousands off guard, with the unseasonal downpour causing widespread damage to homes and a school to be closed.
Mandurah and Rockingham copped the brunt of the weather overnight and stormy weather is forecast for much of the south of the state with people in Collie being told to prepare for flooding.
The Bureau of Meteorology's Neil Bennett told Radio 6PR Collie had received more than 100 millimetres of rain since 9am on Wednesday and the town's mayor Wayne Sanford said water was already knee-high in some areas.
The Department of Fire and Emergency Services has warned the Collie River may reach minor flood level on Wednesday.
The department has warned water will be fast flowing and levels will rise quickly so people should be ready to relocate if need be.
Significant rainfall has been recorded in the Collie River catchment for the 24 hours to 9am, including 66 millimetres in Sandalwood and 53 millimetres in Henty Brook.
The overnight rainfall is causing significant stream rises in the lower Collie River catchment.
Amaroo Primary School and Allanson Primary School in Collie have been closed for the remainder of the day.
Mandurah recorded 70.2 millimetres of rain making it the second wettest day for the town in 11 years - and it might not be over yet, with the chance similar conditions could redevelop later in the day.
About 4000 homes were left without power on Wednesday morning in the Mandurah area, which was hit with a spectacular thunderstorm on Tuesday night.
Rockingham General Hospital sustained severe damage following the storm activity.
Rockingham Peel group executive director Geraldine Carlton said inpatients were being cared for but had been relocated within the hospital and some elective surgery had been postponed.
"Rockingham General Hospital remains structurally and electrically safe but significant damage has occurred including flooding of some areas," she said.
Much of Perth's metropolitan area experienced heavy rain but escaped any real damage - although several flights arriving and departing the city were held on the tarmac because of fears of lightning.
Bad weather is continuing throughout south-western parts of the state.
- Did you take any photos of the storm overnight? Send them in to us - firstname.lastname@example.org
State Emergency Service personnel answered more than 100 calls for help after a severe thunderstorm hit Rockingham and Mandurah overnight.
Rockingham was worst affected, recording 86 calls for assistance.
Reported damage involved mostly flooding and roof damage and the number of calls for help was expected to increase.
Photos taken by listeners to Coast FM captured the moment the lightning display coincided with a fireworks show held at the foreshore for the finale of the Community Christmas Celebrations.
More bad weather on its way
Thunderstorms are forecast for parts of Western Australia including people in, near and between Perth, Mandurah, Bunbury, Busselton, Margaret River and Bridgetown and surrounding areas.
The overall weather pattern is unusual for this time of year and rainfall amounts are well above normal in some areas.
This weather could damage homes and make travel dangerous. A warning previously in place for people in areas east of Northam to Narrogin to Mount Barker has been cancelled.
People in the Goldfields and Great Southern region are also being warned to prepare for severe thunderstorms.
This includes people in, near and between Hopetoun, Lake King, Norseman, Ravensthorpe and Salmon Gums.
This type of weather is not unusual for this time of year but could cause major damage to homes and make travel dangerous.
Who to contact:
- If your home has been badly damaged by storm call the SES on 132 500
- In a life threatening situation call 000
- For the latest weather information visit www.bom.gov.au or call 1300 659 213
- For information about road conditions contact Main Roads WA on 138 138
- To report downed powerlines call Western Power on 13 13 51