Atmospheric rivers swamp coastal B.C., creating flood and avalanche risks

The latest forecast for southern British Columbia calls for periods of heavy rain into Friday, setting off avalanche risks, flood watches and high streamflow advisories for area waterways.

The warning in a joint statement from B.C.’s Emergency Management Ministry and the Ministry of Water, Land and Resource Stewardship comes after the first deluge dropped more than 100 millimetres in some areas, including Tofino and Bella Bella, over a 24-hour period.

“People in coastal regions should use caution through the week, as British Columbia will continue to experience a series of atmospheric rivers affecting the Pacific Northwest,” the statement said.

Environment Canada upgraded its rainfall warnings to orange on Tuesday for B.C.’s central coast and the west coast of Vancouver Island, with up to 200 millimetres of rain possible by Wednesday.

The weather agency also issued a statement about a higher risk for localized flooding in the Interior, where the Kootenay region and Highway 1 near Rogers Pass face the possibility of elevated snowmelt as temperatures rise.

The Central Coast Regional District has issued an evacuation alert and order for parts of Martin Valley due to flooding and the risk of a landslide from Mt. Caro Marion.

A state of local emergency was declared Tuesday around 9:30 p.m. under the Emergency and Disaster Management Act, citing significant threats to public safety and the need to control travel and support evacuations.

The alert applies to households along Laneway and Twin Lakes Road, with residents urged to prepare to evacuate or shelter in place as conditions may change with little notice.

Officials say transportation routes are also affected by an evacuation order east of the Martin River.

This comes as a lower-level rainfall warning is in place for Whistler, Howe Sound, the Fraser Valley and the North Shore of Metro Vancouver, as well as for inland portions of Vancouver Island, with amounts forecast between 60 and 150 millimetres of rain depending on the location.

The highest recorded rainfall Monday was at the Estevan Point weather station off Vancouver Island’s west coast where 142 millimetres was recorded, while Terrace, in northwestern B.C., received 38 centimetres of snow and wind gusts on Sartine Island off Vancouver Island’s northern tip reached 144 kilometres an hour.

Warming conditions combined with heavy mixed rain and snow triggered cautions for high avalanche danger for parts of Vancouver Island, the Lower Mainland, the Sunshine Coast and much of northwestern B.C., as well as Interior regions along the Rockies.

“Avoid exposure to avalanche terrain as rain continues to soak the snowpack,” says Avalanche Canada’s forecast for inland Vancouver Island.

On Tuesday, the B.C. River Forecast Centre downgraded Northern and Western Vancouver Island from a flood watch to a high streamflow advisory.

“As rainfall rates eased, rivers on northern Vancouver Island have begun to recede,” it said.

The rest of the island, it said, remains on a high streamflow advisory as rain is expected to continue throughout the week.

“Smaller rivers and streams throughout Vancouver Island may respond quickly to intense rainfall and could experience rapid rises during periods of heavy precipitation.”

High streamflow advisories also remain in effect for the North and South Coast as well as for the lower and upper regions of the Fraser River.

But the government statement says high streamflow advisories for the south coastal regions could escalate through the week based on locations of heaviest rainfall.

The forecast centre says the Central Coast, including tributaries and smaller streams around Bella Coola, Rivers Inlet and other coastal communities, remain on flood watch.

The province says areas within the Interior may also see high stream flows later this week “due to the strength of the storm system and increase in temperatures,” referring to a melt of mountain snowpack.

“Advisories may be issued for those areas later in the week,” the statement said.

This report by The Canadian Press was first published March 17, 2026.