Howe Sound and Sea to Sky area expected to be at epicenter of continuing deluge
Another torrent of heavy rain is expected on British Columbia's south coast as the latest atmospheric river brings warm air that also increases the risk of avalanches.
Alyssa Charbonneau, a meteorologist with Environment Canada, says the heaviest downpours are expected over Howe Sound and the Sea to Sky area, although the entire region will see more rain in the coming days.
The Met Office maintains a rain warning covering Squamish, Whistler and other communities near Howe Sound, saying another 60 to 100 millimeters are forecast before the rain turns to light showers on Tuesday morning.
There may be some breaks in the heavier rains, but Charbonneau says it is a “cumulative event” and flooding concerns are due to its long duration.
She says the systems are also carrying warm air that is driving up freezing levels, and Avalanche Canada's map shows danger rates are high in many areas.
The danger is classified as “high” in the southern Chilcotin and Pacific mountain ranges, including Whistler and Pemberton, as well as in northwestern British Columbia, and along the border with Alberta, extending as far west as Nelson and Castlegar, British Columbia.
The meteorologist says heavy rain soaks the snow, creating dangerous avalanche conditions, and travel to alpine areas is not recommended.
Avalanche danger is rated as “considerable” in mountains across the Fraser Valley and parts of the central hinterland, while it is rated as “moderate” along the mountains of the North Shore, Sunshine Coast and parts of the island. from Vancouver.
The meteorologist's map indicates that the risk is expected to decrease slightly on Tuesday.
Meanwhile, the British Columbia River Forecast Center maintains flood watches for all of Vancouver Island and the south coast, including parts of the Fraser Valley, while lower level flow advisories are in effect for the central and northern coasts. .
A bulletin from the center says a series of "powerful" storms have brought between 50 and 200 mm of rain across most of the region since Friday.
River levels are expected to peak in most areas on Monday and Tuesday.
The center had issued a flood warning for the Sumas River when the nearby Nooksack River in Washington state overflowed its banks, but the forecaster lowered the warning later Sunday, saying water levels across the border were receding. .
Charbonneau says the rain is expected to persist until sometime in the middle of the week, perhaps Wednesday night, before tapering off.
"We see things cooling into the season and it looks like we're going to have a period of dry weather over the weekend," he says.
Still, he cautions, the long-range forecast for British Columbia's south coast should be taken “with a grain of salt” this time of year because it can change quickly.
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