Environment Canada has upgraded a weather alert for parts of B.C.’s South Coast to a rainfall warning.
The warning applies to Metro Vancouver, the Sunshine Coast and Howe Sound. The Fraser Valley, Whistler and eastern, western and central Vancouver Island remain under a special weather statement.
The national weather agency is forecasting between 75 and 150 millimetres of rain to fall within a 48-hour window starting Friday morning.
The heavy rain is expected to arrive with a pair of frontal systems loaded with moisture from an “atmospheric river” flowing off the Pacific Ocean, according to Environment Canada.
“A ‘river’ of atmospheric moisture is flowing high above the Pacific Ocean this morning, and taking aim at B.C. Pockets of heavy rain will invade the North and Central BC Coast today through tonight, but it is the South Coast that will experience the heaviest rainfall in coming days,” Global BC meteorologist Mark Madryga said.
“From Friday morning through early Sunday, rain will be frequently heavy especially in areas closest to the mountains.”
Freezing levels are also forecast to climb above 2,500 metres on Saturday, potentially adding snowmelt to the rainfall.
“Swelling of local streams and localized flooding are likely during this time,” the rainfall warning states.
“Heavy downpours can cause flash floods and water pooling on roads.”
Drivers are reminded to slow down and turn their headlights on, and to watch for possible washouts near waterways.
Residents are also being reminded to clear out any potential drainage sites on or near their property to prevent flooding.