A complex snowpack has led to several recent avalanche incidents, including a fatal avalanche north of Pemberton, close to the Sea to Sky boundary. Clues of instability may not be obvious, so stick to low-angle terrain at all elevations and avoid overhead hazard.
A couple of problematic layers may be found around 50 to 120 cm deep, including weak layers of surface hoar and faceted grains above a hard melt-freeze crust. There remains potential for storm slab avalanches to step down to these layers, resulting in large and destructive avalanches.
Fresh snow with moderate to strong southwest winds will be forming fresh storm slabs. These slabs may be the most reactive in wind loaded areas.
Keep in mind that this fresh snow could also be hiding wind slabs that may still be reactive to human triggers.
TUESDAY NIGHT - Flurries, 5-10 cm / southwest wind, 20-40 km/h / alpine low temperature near -5
WEDNESDAY - Snow, 10-15 cm / southwest wind, 40-60 km/h / alpine high temperature near -2
THURSDAY - Mainly cloudy / light southwest winds / alpine high temperature near -4
FRIDAY - Snow, 20 cm / southwest wind, 30-50 km/h gusting to 75 km/h / alpine high temperature near -2 / freezing level 1500 m
There was a fatal avalanche in the South Coast Inland region (near the Sea to Sky boundary) north of Pemberton in the Goat Peak area on Monday. This avalanche resulted in two fatalities. It was reported to be a size 2.5 persistent slab avalanche on a west aspect, around 1650 m. The RCMP press release can be viewed here.
A size 2.5 avalanche was triggered on Monday by a skier on Rainbow Mountain, which resulted in a full burial and, thankfully, a successful rescue. The avalanche failed on a 60 cm deep crust and facet layer on a northeast aspect around 1800 m.
A size 3 persistent slab avalanche was reported on Mount MacBeth on Monday, check out this MIN report for details of this observation.
These avalanches highlight the ongoing potential to trigger persistent weak layers in the snowpack.
A small (size 1) avalanche was also triggered on Monday by skiers on a north aspect in the Whistler backcountry, most likely in recent storm snow.
There has been up to 40 cm of recent snow in the region, with another 10-15 cm expected during the day on Wednesday. Moderate to strong southwest winds are expected to redistribute this snow, forming storm slabs in lee terrain features.
Two potential concerning weak layers may be present in the snowpack:
To date we have mostly seen sporadic avalanche activity on these layers, but they remain possible to trigger where they exist in the mountains.
The remainder of the snowpack is well-settled.
