Avalanche Forecast
Issued: Dec 20th, 2020 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs, Loose Dry and Deep Persistent Slabs.
Benjamin Firth,
Up to 50cm of new snow has fallen over the past several days. It will need time to stabilize. Be cautious of wind effected areas on all aspects
Summary
Weather Forecast
Monday and Tuesday: Cloudy with clear periods and isolated flurries with trace precip. Alpine temps as low as -12 °C. Ridge wind west: 20 km/h gusting to 45 km/h.
Tues through Fri: A mix of sun and cloud. Precipitation: Nil. Alpine temperature: Low -14 °C, High -8 °C. Ridge wind west: 15 km/h. Freezing level at valley bottom.
Snowpack Summary
Up to 50cm of low density storm snow over last few days. SW winds continue to build wind slabs in the alpine and treeline. Decomposing surface hoar down 30cm to 50cm in sheltered locations treeline and below. The midpack is generally supportive with a weaker base consisting of facets and depth hoar. Avg depth is 65cm - 160cm depending
Avalanche Summary
Avalanche control on Parkers and Gravel Slopes today we had stubborn results, 2 out 14 avalauncher rounds produced up to size 2. Hand charging on gravel slopes no significant results. Several natural avalanches out of crossloaded wind effected alpine terrain up to size 3. Cornices continue to build at ridgetop but no observed failures.
Confidence
Problems
Wind Slabs
New snow and moderate to strong winds forming wind slabs on leeward and cross-loaded terrain features.
- Minimize overhead exposure during periods of heavy loading from new snow, wind.
- Be careful with wind loaded pockets, especially near ridge crests and roll-overs.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Dry
New snow may be reactive on the Dec 14th layer and in steep terrain
- Carefully assess open slopes at and below treeline where buried surface hoar may be preserved.
- Be careful of loose dry power sluffing in steep terrain.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Deep Persistent Slabs
Be cautious of thick to thin snowpack areas being likely trigger locations. The new windslabs forming have the potential to step down to the weakness at the base of the snowpack.
- If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
- Use caution in thin snowpack areas.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 21st, 2020 4:00PM
