Ongoing stormy weather will continue to create dangerous avalanche conditions.
Be sure to choose low-consequence terrain, far away from overhead hazards.
Three problematic persistent weak layers exist in the upper 170 cm of the snowpack. Recent snow is adding load to these layers, and large destructive avalanches is possible. Remote trigger and release on low-angle slopes is also likely.
Additional snow, combined with strong wind, will keep building fresh reactive storm and wind slabs. Storm slabs in motion may step down to deeper layers, resulting in large avalanches.
Poor visibility restricted field observations on Wednesday and Thursday, but natural avalanche activity has likely occurred from the ongoing strong wind and heavy loading during the storm.
Very large natural avalanches (size 2 to 3) and human-triggered persistent slabs ( size 1.5 to 2.5) were reported continously with some being accidental or remote (from a distance) on all aspects and elevations, even from low-angle slopes.
The latest storm added 25 to 40 cm of additional new snow to the complex snowpack, along with strong to extreme westerly winds.
Three persistent weak layers of concern may be found in the upper 170 cm of the snowpack:
50 to 70+ cm down is a layer of surface hoar in sheltered areas, or a melt-freeze crust on sun-exposed slopes from mid-February.
80 to 120+ cm down is the early-February layer of surface hoar in wind-sheltered terrain and a crust on sun-exposed slopes.
100 to 140 cm down is the late-January layer of surface hoar and facets over a melt-freeze crust.
All of these persistent layers have continued to produce large avalanches in the region.
The remainder of the snowpack below is well consolidated.
Thursday Night
Cloudy. 10 to 25 cm of snow. 60 km/h southwest ridgetop wind. Treeline temperature -6 °C. Freezing level 1500 m.
Friday
Cloudy. 10 to 15 cm of snow. 50 km/h west ridgetop wind. Treeline temperature -6 °C. Freezing level 1500 m.
Saturday
A mix of sun and clouds. 2 to 4 cm of snow. 40 km/h west ridgetop wind. Treeline temperature -8 °C.
Sunday
Mostly sunny. 40 km/h west ridgetop wind. Treeline temperature -4 °C. Freezing level 1800 m.
More details can be found in the Mountain Weather Forecast.
