Avalanche Forecast
Regions: Sea To Sky.
Although the storm has subsided, human triggered avalanches remain likely, especially in wind loaded areas.
Keep in mind that a persistent weak layer is now buried up to 100 cm. Avalanches on this layer will become harder to predict, so a conservative approach is important.
Confidence
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast. Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
TUESDAY NIGHT - Mainly cloudy with a few flurries / light southwest wind, switching to light north wind / alpine low temperature near -10Â
WEDNESDAY - Sunny with cloudy periods / light north wind / alpine high temperature near -9
THURSDAY - Mainly cloudy with a few flurries, / moderate west wind / alpine high temperature near -7Â
FRIDAY - A mix of sun and cloud / light to moderate west wind / alpine high temperature near -5
Avalanche Summary
Avalanches are expected to remain easy to trigger on Tuesday in many areas, especially in wind loaded terrain at higher elevations.
There have been reports of size 1-2 natural, human and explosives triggered avalanches every day since Saturday. Many of these avalanches have failed on the recently buried persistent weak layer.
Snowpack Summary
50-100 cm of recent fresh snow sits on a persistent weak layer that consists of facets at upper elevations, surface hoar in sheltered areas, a melt-freeze crust below 1900 m, and a sun crust on south-facing slopes. There could be more than 100 cm on this layer in wind loaded areas.
A crust from early December may be found around 200+ cm deep in the snowpack. In shallow rocky areas, it may still be possible to trigger this layer. In deeper snowpack areas, it appears to be unreactive.
Terrain and Travel
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Be aware of the potential for large avalanches due to the presence of a persistent slab.
Avalanche Problems
Storm Slabs
Recent fresh snow combined with strong southerly winds has formed reactive storm slabs in many areas, especially wind loaded terrain features.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1 - 2.5
Persistent Slabs
50-100 cm of snow sits on a widespread weak layer that consists of facets, surface hoar, or a crust depending on location. Avalanches may propagate widely on this layer.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1.5 - 2.5