Avalanche Forecast
Issued: Feb 2nd, 2021 4:00PM
The alpine rating is Storm Slabs and Persistent Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeAlthough 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.
Summary
Confidence
Weather Forecast
TUESDAY NIGHT - Mainly cloudy with a few flurries / light southwest wind, switching to light north wind / alpine low temperature near -10
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 -7
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.
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
Expected Size
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
Expected Size
Valid until: Feb 3rd, 2021 4:00PM