Hydro crews are scrambling to return power to tens of thousands of homes on B.C.'s South Coast as whipping winds sweep through the region.

Much of Metro Vancouver, the Fraser Valley and Vancouver Island are under Environment Canada wind warnings Tuesday, with some areas seeing gusts of up to 90 kilometres an hour.

That's more than fast enough to send tree branches crashing down onto power lines, and BC Hydro spokesperson Tanya Fish said electricity was cut off to 43,000 people by mid-morning.

"The hardest hit areas are Abbotsford and Surrey," she said. "I can tell you that all hands are on deck right now, our crews are out there working to get power back as quickly as possible."

According to Environment Canada, some of the strongest winds can also be expected in Langley, Richmond, Delta, Chilliwack, Hope and Victoria.

The windstorm comes on the heels of intense overnight rainfall, which made for poor visibility on roads. There were a number of violent crashes, including an accident on Highway 10 in Surrey that left an SUV upside down and a car's front end mangled.

The RCMP is investigating if poor weather was a factor in the crash.

On Vancouver Island, winds downed a tree onto power lines in Courtenay overnight, sparking a fire and cutting power to about 3,000 Hydro customers in the area.

Firefighters are reminding people about the dangers posed by live wires.

"Be careful during the heavy windstorms when trees or limbs fall across the lines," said Deputy Chief Dennis Henderson of the Courtenay Fire Department. "Treat them as live and get ahold of BC Hydro and… call 911."

A rainfall warning issued Monday has ended, but Environment Canada warns the next rainstorm isn't far behind. More strong wind and heavy rain are expected to arrive on the South Coast early Wednesday, and it could be enough to cause flooding.

"It is possible that falling leaves may block storm drains, combining with significant rain to cause local flooding," Environment Canada cautioned in a special weather statement.

There is also the potential for more hazardous driving conditions, the weather agency added, particularly in mountainous areas such as the Sea-to-Sky Highway.

For the latest on power outages, visit the BC Hydro website. 

With files from CTV Vancouver's Nafeesa Karim