Avalanche Forecast
Regions: Brandywine, Homathko, Sea To Sky, Spearhead.
Very large avalanches will occur over the next few days.
Avoid avalanche terrain!!!
Confidence
High
Avalanche Summary
Observations from Tuesday confirm persistent slab avalanches are still a serious concern, as several size 3 natural avalanches were observed in treeline and alpine terrain in the Whistler area. There were also many size 1.5 to 2.5 storm slab avalanches over the past few days.
Looking forward we can expect warm sunny weather to cause many very large slab avalanches, as well as widespread wet loose avalanches and cornice failures.
Snowpack Summary
Rapidly rising freezing levels on Thursday will melt surfaces on all terrain except for high north-facing slopes. Over 100 cm of snow from the past week is rapidly settling, but some storm slab instabilities may still be present, especially in wind-affected areas.
A weak layer composed of facets on a crust is buried 150 to 250 cm deep and remains sensitive to both human and natural triggers. The snowpack below this interface strong and bonded.
Weather Summary
Wednesday Night
Clearing skies. 25 km/h northeast ridgetop wind. Treeline temperature -4 °C.
Thursday
Mostly sunny. 25 km/h northwest ridgetop wind. Treeline temperature +3 °C with freezing level climbing to 3000 m by midday.
Friday
Mostly sunny. 15 km/h north wind. Treeline temperature +6 °C with freezing level climbing to 3300 m.
Saturday
Sunny. 45 km/h southeast ridgetop wind. Treeline temperature +8 °C with freezing level sustained at 3300 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid avalanche terrain during periods of strong sun.
- Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.
- Cornice failure may trigger large avalanches.
Avalanche Problems
Persistent Slabs
Very large persistent slab avalanches are occurring regularly in treeline and alpine terrain. The intense warming over the next few days will make these even more likely. These avalanches could run into below treeline terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Likely - Very Likely
Expected Size: 3 - 4
Loose Wet
Sudden warming will produce widespread wet loose avalanches, especially on steep sun-exposed slopes.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Very Likely
Expected Size: 1 - 2
Storm Slabs
Warming, and/or cornice falls, could trigger slabs in the recent storm snow.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5