Avalanche Forecast
Regions: Boundary, East Stikine, Kispiox, Ningunsaw, Northwest Coastal, Northwest Inland, Stewart, West Stikine.
Assess for wind slabs in steep terrain. Cornice failures during daytime warming could trigger buried weak layers, particularly in northerly alpine terrain.
Confidence
Moderate
Avalanche Summary
No new avalanches were observed on Tuesday. A few small loose avalanches and cornice failures were observed on Monday.
On Sunday, cornice failures triggered two very large (size 3 to 5) natural persistent slab avalanches. There were multiple step-downs visible in the crowns, and these avalanches likely failed on the weak layers described in the Snowpack Summary.
Cornices continue to be a prime suspect for triggering large, destructive avalanches.
Snowpack Summary
Around 10 cm of dry snow may be found on high elevation north aspects, with potentially deeper deposits in immediate lee terrain due to strong southwest wind. Elsewhere, a hard melt-freeze crust is likely found on the snow surface, which may soften with daytime warming.
At alpine and treeline elevations, a layer of surface hoar that formed in early March may be found around 70 to 120 cm deep. A layer of facetted grains and a crust that formed mid-February may be found 120 to 200 cm deep.
The remainder of the snowpack is consolidated.
Weather Summary
Wednesday Night
Mostly cloudy. 20 km/h southeast ridgetop wind. Treeline temperature -2 °C. Freezing level 1100 m.
Thursday
A mix of sun and cloud. 20 to 30 km/h south ridgetop wind. Treeline temperature +2 °C. Freezing level 1500 m.
Friday
Cloudy with 5 to 10 cm of snow. 20 to 40 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1300 m.
Saturday
Cloudy with 5 cm of snow. 10 to 20 km/h southwest ridgetop wind. Treeline temperature 0 °C. Freezing level 1300 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Be aware of the potential for large, destructive avalanches due to deeply buried weak layers.
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Limit exposure to steep, sun exposed slopes, especially when the solar radiation is strong.
Avalanche Problems
Persistent Slabs
Buried weak layers from February and March continue to produce periodic large avalanches. Large loads like cornice falls are a prime trigger for them. Avalanches are most likely in north-facing alpine terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 3 - 5
Wind Slabs
Southwest wind and recent snow may have formed slabs in lee terrain features.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1 - 2