Avalanche Forecast
Issued: Feb 24th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
bchristie,
Avalanche Canada
Start on smaller features and gather information before jumping into a big, committing line.
Large avalanches are possible on isolated features in the alpine, and even small avalanches can be dangerous in steep terrain or around terrain traps.
Summary
Confidence
Weather Forecast
Thursday Night: Mostly clear, increasing cloud in early morning. No new snow expected. Light west ridgetop wind. Freezing levels at valley bottom. Alpine high around -4 °C.
Friday: Increasing cloud through the day, mostly cloudy by the afternoon. Possible trace of snow expected. Ridgetop winds increasing to strong from the southwest by the afternoon. Freezing level rising to around 500 m. Alpine high around -5 °C.
Saturday: Mostly cloudy. 5-12 cm of snow expected. Strong southwest ridgetop winds, trending to extreme at higher elevations. Freezing level at valley bottom, rising to 500 m in the afternoon.
Sunday: Mostly cloudy. 5-15 cm of snow expected overnight, and another 5-25 through the day. Strong south ridgetop winds, trending to extreme southwest at higher elevations. Freezing level rising to around 1000 m.
Avalanche Summary
On Thursday, a professional operation east of Stewart reported two large avalanches triggered by natural ice fall in steep terrain.
On Wednesday, professional operations around the region were reporting small, natural, loose dry avalanches in steep terrain, and small, rider triggered windslab avalanches on isolated features.
On Tuesday, professional operations west of terrace reported a few natural, cornice triggered windslab avalanches up to size 2.5 in the alpine. There were also isolated reports from around the region of natural windslab avalanches up to size 2, and natural and rider triggered sluffing and loose dry avalanches up to size 2 in steep terrain.
Snowpack Summary
10-30 cm of mostly low density, loose snow overlies a variety of old, generally wind-affected surfaces, and a thin temperature crust below tree line. In specific areas, shifting winds have formed soft slabs in the immediate lee of terrain features that are exposed to the wind.
The upper snowpack appears to be starting to bond to the mid February rain crust, but we are not ready to completely trust that bond until it has weathered some significant warming or precipitation.
This obvious, 10-30 cm thick rain crust beneath the recent snow effectively caps the underlying snowpack, making human triggering of avalanches on deeper weak layers very unlikely.
Terrain and Travel
- Use caution above cliffs and terrain traps where even small avalanches may have severe consequences.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Wind slabs may be poorly bonded to the underlying crust.
Problems
Wind Slabs
Recent, low density storm snow has been redistributed by moderate to strong west through north winds, forming thin, soft, reactive windslabs.
Older, larger, firmer windslabs sit on top of the mid February rain crust on most aspects. Deeper avalanches failing at this layer are less likely, but could have more serious consequences. Larger triggers like cornice or ice falls have the potential to trigger deeper windslabs.
The most likely place to trigger a wind slab is near ridge crest and on convex terrain features, where the slope rolls away from you.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 25th, 2022 4:00PM
