Hefty alpine snow raises avalanche risk in B.C., Christmas chill looms
Heavy snows will continue across the B.C. mountains through Thursday, elevating the risk of avalanches. Meanwhile, a blast of frigid air will arrive in time for Christmas, along with a chance for snow at lower elevations.
B.C. is in the middle of a stormy week that has brought heavy rain, copious snow and freezing rain at times. Some areas could see accumulative rainfall totals of 50-75 mm through Thursday, while the mountain passes are in the midst of a sluggish storm that will bring local totals of 30-50 cm during the same time. As a result, the avalanche danger ratings have been raised in the mountain passes. Looking further ahead, a blast of cold air could lead to one of the coldest Christmases on record in places like Vancouver. More on the timing and impacts, below. Could see
MUST SEE: Canada's 2021 Holiday Snow Report
THROUGH THURSDAY: LOWS MERGE TO BRING MORE RAIN, AND MOUNTAIN SNOW
Two lows have merged as a single storm in B.C. that is bringing rainfall to the South Coast and mountain snow for the alpine regions.
Rainfall on the Lower Mainland and Vancouver Island will ease off by Thursday morning. In terms of accumulative rainfall amounts from the systems, the Lower Mainland can expect between 30-60 mm of rain through Thursday, with higher totals possible in areas where terrain enhances precipitation rates. 50-75 mm is anticipated for the eastern Fraser Valley and southwestern Vancouver Island.
Meanwhile, widespread winter storm warnings are in place for a slow-moving winter storm that will continue to trek across the southern B.C. Interior. Heavy snow will continue before tapering off to flurries by Thursday morning.
Locally 30-50 cm of snow is forecast across the mountain passes and parts of the Rockies through Thursday. Weather in the mountains can change suddenly resulting in hazardous driving conditions.
"Surfaces such as highways, roads, walkways and parking lots may become difficult to navigate due to accumulating snow. Rapidly accumulating snow could make travel difficult over some locations. Visibility may be suddenly reduced at times in heavy snow," Environment and Climate Change Canada (ECCC) says in the winter storm warning.
In addition to the wintry precipitation, intense wind gusts will ease off Wednesday overnight. Gusts of 50-70 km/h are expected for coastal and Interior regions. However, winds along the northern Vancouver Island coast will ramp up again Thursday afternoon.
As a result of the mountain snow and what is already on the ground, the avalanche danger is raised across the passes. Danger ratings will range from moderate to high. People are being asked to avoid the backcountry, ranging in altitudes from the alpine to below the tree line.
LOOKING AHEAD: UNUSUAL AND EXTENDED STRETCH OF ARCTIC AIR WITH POTENTIALLY RECORD BREAKING COLD
Arctic air, potentially dangerous, will spread over Western Canada late week and on the Christmas weekend, with an unusual and extended stretch of Arctic air set to blast B.C.
While freezing levels for the South Coast will temporarily bump up mid-week with the arrival of the system, freezing levels are forecast to bottom out on Sunday and beyond, with daytime high temperatures for Vancouver sitting near the freezing mark for Christmas.
Vancouver actually has the potential of breaking records with this cold. A daytime high of 0°C is currently forecast for Saturday (Christmas Day). The coldest daytime high recorded on Christmas for Vancouver was -1.7°C tied in 1924, 1964 and 1971.
Whatever the final temperature is, it will be one of the coldest Christmases, and also Boxing Days, on record for the Vancouver area.
This extraordinary stretch of frigid weather expected for the South Coast will continue through the end of the month, with additional opportunities for snow, rain and even mixing at times.
Thumbnail courtesy of DriveBC.
Check back for the latest forecast across British Columbia.