B.C.’s South Coast in for a soaking as season’s first atmospheric river arrives

People living on B.C.’s South Coast will want to break out their rain coats and galoshes, as the season’s first notable fall storm arrives.

Environment Canada has issued rainfall warnings for most of B.C.’s South Coast including Metro Vancouver, most of Vancouver Island, Howe Sound, Whistler, and the Sea to Sky Highway from Squamish to Whistler, as an atmospheric river moves into the region.

Global BC Senior meteorologist Kristi Gordon said the incoming system was classified at a rank of AR3 on a scale of one to five, according to the Center for Western Weather and Water Extremes. That’s significant enough to douse the region, but not as intense as some fall and winter storms B.C. has seen in recent years.

1:41 B.C.’s South Coast in for a soaking as season’s first atmospheric river arrives

Metro Vancouver is forecast to receive from 40 millimetres of rain up to 80 millimetres close to the North Shore mountains.

Meanwhile, the Sunshine Coast could get up to 60 millimetres, Howe Sound could get up to 110 millimetres, and Vancouver Island could get from up to 80 millimetres in the east to 200 millimetres on the west coast. Whistler and the Sea to Sky Highway area could also receive up to 110 millimetres.

Gordon said the heavy rain was forecast to stretch over a 36- to 48-hour period from Tuesday evening into Wednesday.

B.C.’s Ministry of Environment and Climate Change also issued a bulletin Tuesday evening, warning that the heavy rain could cause other hazards, following a summer of drought and wildfires.

5:39 Heavy rain after summer drought raises flood risk

“Rainfall on impacted areas can generate high surface water runoff and erosion due to a lack of vegetation, leading to a possibility of localized flooding and landslides — although widespread or severe impacts are not expected as part of this atmospheric river system,” the ministry said in a media release.

The B.C. River Forecast Centre has also issued high-streamflow advisories for multiple regions, rivers and their tributaries, including the South Coast, North Thompson, South Thompson, Upper Columbia, Vancouver Island, Sunshine Coast, and Howe Sound.

People are being urged to stay away from fast-moving waterways and not to drive through flood water.

The province is also using the storm as a chance to reiterate its emergency preparedness advice, including preparing homes for possible flooding by clearing storm drains, gutters and perimeters and packing grab-and-go bags that can be used for any emergency situation.

Global News spoke with Environment Canada meteorologist Alyssa Charbonneau, on Wednesday.

“Atmospheric rivers are more common in B.C.’s fall. It is one of the ways that recharges our rainfall after relatively dry summers,” she said.

“They are very narrow bands of high-intensity moisture, and as it approaches the coast and the mountains it releases its rain.”

Charbonneau said now is a good time to check drainage around homes and neighbourhoods to help mitigate localized flooding.