The latest atmospheric river to wash over British Columbia is expected to soak parts of the South Coast with as much as 150 millimetres of rain in a series of waves that won’t relent until Thursday, says Environment Canada.
Rainfall warnings are in place across the west coast of Vancouver Island and the inner South Coast, including Metro Vancouver and the Fraser Valley.
The storm’s first torrent on Tuesday is to be followed by a second intense gush Wednesday and a final one early Thursday, says the weather office.
Forecasters warned warmer temperatures accompanying the storm could push freezing levels as high as 2,500 metres by Wednesday, melting mid-level snowpacks and swelling waterways.
Emergency Management B.C. is urging homeowners to prepare for potential floods by clearing storm drains, cleaning gutters and confirming where sandbags can be picked up from local governments.
High streamflow advisories have been posted across all of Vancouver Island and the South Coast.
High avalanche risk
Meanwhile, Avalanche Canada raised the risk of a slide on Vancouver Island, South Coast and Sea-to-Sky mountains to high, meaning very dangerous avalanche conditions exist.
“Wait out this storm,” said a post on the Avalanche Canada website, advising that travel on southern coastal mountains was not recommended until conditions improve.
“Expect loose, wet avalanches to be widespread at all elevations, and easily triggered,” the site said.
The B.C. government has closed a section of Highway 1 in the Fraser Canyon due to avalanche risk. Travel is not permitted on this route, between Yale and Boston Bar, until further notice.
Although the city of Abbotsford, which was badly damaged during catastrophic flooding in November, was covered by rain warnings linked to the storm, forecasts show the region will likely dodge the worst of the downpours.
Environment Canada says that part of the Fraser Valley could see no more than 10 millimetres of rain Tuesday, up to 40 millimetres overnight and a maximum of 20 millimetres Wednesday.
Abbotsford remains under a state of emergency, which was declared as rivers rose amid torrential rain in mid-November, and the city has told residents in low-lying areas to prepare for the potential of localized flooding.
The provincial government has urged people living in flood zones to be prepared with a grab-and-go bag for each household member in case they are forced to evacuate