Avalanche Forecast
Issued: Jan 31st, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Wind Slabs.
JA,
Avalanche Canada
Incremental new snow with moderate southwest winds will continue to build wind slabs and add stress to the deep persistent problem. Continue to be patient and conservative in your terrain choices.
Summary
Confidence
Moderate
Avalanche Summary
Highway 93 patrol on Sunday noted isolated wind slab activity to size 1.5 and several deep persistent slab avalanches up to size 2.5 in the alpine on southerly aspects likely occurring Friday and Saturday.
Of note is how sensitive the deep persistent problem is to additional load i.e. 10mm of precipitation with wind was enough to initiate a significant cycle on this layer January 27 and 28th.
Don't forget to post avalanche observations to the MIN.
Snowpack Summary
5cm Monday morning adding to the up to 20cm of settled new snow during the past week. Previous moderate to strong northerly winds and present moderate southwesterly winds have added to variable wind slab development in the alpine and exposed tree line. Generally, the bottom of the snowpack is weak facets and depth hoar. The snowpack ranges from 50 to 120cm.
Weather Summary
A series of low pressure systems and troughs will bring isolated to light precipitation through the remainder of the week. Up to 5mm is possible by Friday. Temperatures will be seasonal trending milder on Thursday. Winds will be consistent light to moderate values from the southwest.
Detailed weather forecasts from Avalanche Canada: https://www.avalanche.ca/weather/forecast
Terrain and Travel Advice
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
Problems
Deep Persistent Slabs
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Avalanches initiating in the upper snowpack are likely to step down to this layer and gain significant mass.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
Previous north winds created wind slabs on southerly slopes which don't typically see wind loading. Present southwest winds are creating new wind slabs on typical lees.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Feb 1st, 2023 4:00PM
