Avalanche Forecast
Issued: Jan 30th, 2023 4:00PM
The alpine rating is Deep Persistent Slabs and Wind Slabs.
, the treeline rating is , and the below treeline rating is Known problems includeThe weak base of our snowpack will persist even when the signs indicate an improving trend. Maintain your discipline to not push into bigger terrain.
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.
Don't forget to post avalanche observations to the MIN.
Snowpack Summary
10 to 20cm of soft settled new snow from Jan 27th overlies a weak melt-freeze crust up to 2000m. Wind slabs are present in the alpine and exposed tree line locations. Generally, the bottom of the snowpack is weak facets and depth hoar. The snowpack ranges from 50 to 120cm.
Weather Summary
Transitioning from cold Arctic air back to a westerly flow. Tuesday a series of weak low pressure systems and troughs will bring isolated to light precipitation through the remainder of the week. Up to 10mm is possible by Friday. Temperatures will be seasonal trending milder towards the weekend. Winds will be consistent light to moderate values from the west.
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
North winds at ridge top created wind slabs on Southerly slopes which don't typically see wind loading. The wind slabs from previous moderate to strong SW winds are also still present.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 31st, 2023 4:00PM