Avalanche Forecast
Issued: Jan 29th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
cgarritty,
Avalanche Canada
Green light conditions are in the rearview mirror. Expect widespread new surface instabilities that increase in line with local snowfall amounts and tune in to signs of instability at all elevations. A recently buried weak layer could reach a critical depth on Saturday.
Summary
Confidence
Weather Forecast
FRIDAY NIGHT: Cloudy with flurries bringing 5-10 cm of new snow. Moderate south winds, increasing into the morning.
SATURDAY: Cloudy with flurries bringing 10-15 cm of new snow, increasing overnight. Strong south winds. Alpine high temperatures around -7.
SUNDAY: Cloudy with continuing snowfall bringing 10-15 cm, with 2-day snow totals reaching 40-50 cm, continuing but easing overnight. Moderate south winds. Alpine high temperatures around -6.
MONDAY: Mainly cloudy with isolated flurries and a trace of new snow. Light variable winds. Alpine high temperatures around -9.
Avalanche Summary
Recent avalanche activity has been limited, following a pattern of human and explosives triggered small (size 1) releases; wind slabs where wind loading has occurred and loose dry where it hasn't.
Looking forward, expect progressively touchy conditions and increasing hazard over the coming days with forecast new snow and wind. Along with the usual surface instabilities, concern for a recently buried weak layer is also rising in step with this active weather.
Snowpack Summary
15-25 cm of new snow, favouring the south of the region, is expected to accumulate by the end of the day on Saturday. This will add to 10-20 cm of recent snow sitting on firm, wind affected snow at upper elevations, on surface hoar in sheltered areas, on a melt-freeze crust below 1900 m, and on a sun crust on south-facing slopes. Recent winds have redistributed much of this new snow, creating wind slabs in leeward terrain, and stripping the new snow off of some windward slopes.
A crust from early December may be found around 200 cm deep in the snowpack. In shallow rocky areas, recent test results suggest that it may still be possible to trigger this layer. In deeper snowpack areas it has shown no recent results and appears to be unreactive in these areas.
Terrain and Travel
- Storm slab size and sensitivity to triggering will likely increase through the day.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Be aware of the potential for loose avalanches in steep terrain where snow hasn't formed a slab.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
Problems
Storm Slabs
Saturday's storm will bring together the ingredients for new slab problems to form and become increasingly reactive over the day. Along with touchy wind slabs forming in typical leeward pockets, a critical load may form over a recently buried weak layer, affecting more sheltered locations.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Jan 30th, 2021 4:00PM
