Avalanche Forecast
Regions: Brandywine, Homathko, Sea To Sky, Spearhead.
Dangerous conditions persist. Manage the uncertainty around buried weak layers by sticking to low-angle terrain, avoiding overhead hazard, and communicating with groups around you.
Confidence
Moderate
Avalanche Summary
On Wednesday 2 notable large (size 2) one a skier and one that was remotely triggered avalanches where reported in the whistler region.
Both of these avalanches failed on the persistent slab weakness, with crown depths estimated at 100 cm.
Monday, natural avalanches to size 2 were observed on north and west facing slopes at treeline with crowns up to 1 m.
MIN users continue to report remotely triggered avalanches. Check out the many recent MINs from this week!
Snowpack Summary
A thin melt-freeze crust likely exists on solar aspects as a result of Tuesday's sunshine. Where crust formation hasn't inhibited wind transport, elevated winds, recently northerly, have been redistributing surface snow.
Under the evolving surface, 120 -160 cm of progressively resistant or 'right side up' storm snow is continuing to settle above the problematic crust/facet/surface hoar layer beneath it. This layer continues to show sensitivity to human triggers, and is most concerning at treeline elevations where weak grains like facets and surface hoar are more easily preserved.
Weather Summary
Thursday night
Becoming cloudy. 30-60 km/h southwest ridgetop wind. Freezing level 600 m.
Friday
Cloudy increasing snowfall bringing 10-15 cm of new snow, 40-80 km/h southwest alpine wind. Treeline temperature -5 °C with freezing level to 800 m.
Saturday
Cloudy with heavy snowfall bringing 10-20 cm of new snow, continuing overnight. 50-60 km/h southwest alpine wind. Treeline temperature around -2 °C with freezing level rising to 1200 m.
Sunday
Cloudy with continuing heavy snowfall bringing 10-20 cm of new snow and 2-day totals to 30-50 cm. 40-60 km/h southwest alpine wind. Treeline temperature -2°C with freezing level around 1200 m.
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.
- Remote triggering is a concern, watch out for adjacent and overhead slopes.
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
Avalanche Problems
Persistent Slabs
Buried weak layers are most concerning at treeline elevations. Small avalanches may step down to this layer resulting in very large, destructive avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3
Wind Slabs
Recent storm snow may still react as a slab in wind affected features at higher elevations. Watch for deeper and more reactive slabs near ridgelines.
Recent north winds mean new slabs may be found on a range of aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5