Avalanche Forecast
Regions: Boundary, East Stikine, Ningunsaw, Northwest Coastal, Stewart, West Stikine.
Deep instabilities are present and have produced large avalanches during the storm. The recent storm snow will need time to settle and stabilize, and human triggering is likely.
Confidence
Moderate
Avalanche Summary
On Tuesday, numerous naturally triggered persistent slab avalanches (up to size 3) were reported. A skier remotely triggered a size 1.5 persistent slab from 50 m away.
Natural avalanche activity may taper but human-triggered avalanches are likely on Thursday.
Snowpack Summary
Another 30 + cm is expected Wednesday bringing storm snow totals up to 80 cm over the past few days. Strong to extreme west through southwest wind has created widespread wind effect, with deeper deposits of snow on leeward slopes.
Down 70 to 120 cm a layer of surface hoar, facets, or a thin crust exists.
A persistent weak layer of surface hoar and facets overlying a crust is buried 120 to 150 cm deep. This layer remains reactive, producing large and dangerous avalanches.
Weather Summary
Wednesday Night
Snow 10 cm. 30 to 60 km/h southwest ridgetop wind. Treeline temperature -5 °C. Freezing level 700 m.
Thursday
Snow 5 to 10 cm. 20 to 50 km/h southwest ridgetop wind. Treeline temperature -6 °C. Freezing level valley bottom.
Friday
A mix of sun and cloud, possible flurries up to 5 cm. 25 to 50 km/h northwest ridgetop wind. Treeline temperature -9 °C. Freezing level valley bottom.
Saturday
Cloudy. 10 to 30 km/h north ridgetop wind. Treeline temperature -8 °C. Freezing level valley bottom.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Storm slabs in motion may step down to deeper layers resulting in large avalanches.
- Avoid freshly wind-loaded terrain features.
- Keep in mind that human triggering may persist as natural avalanches taper off.
Avalanche Problems
Persistent Slabs
The persistent slab avalanche problem is and has resulted in large to very large avalanches (up to 3).
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 2 - 3.5
Storm Slabs
Watch for newly formed and reactive storm slabs within the new snow. Potential remains for slabs to step down to deeper persistent weak layers.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Likely
Expected Size: 1 - 2