Avalanche Forecast
Issued: Apr 12th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Deep Persistent Slabs and Loose Wet.
PW,
Avalanche Canada
The storm slab is still very sensitive to human triggering and the potential for this layer to step down to the deeper layers of the snowpack exists.
If the sun is shinning, be mindful of its power to create avalanches at this time of year.
Summary
Confidence
Moderate
Avalanche Summary
While the natural avalanche activity has tapered, the cycle is still ongoing. Storm slabs, loose wet, cornice fall and deep persistent slabs have all been observed and/or reported in the last 36h up to size 3. Heli bombing today produced results up to size 3.5, some avalanches initiating as soon as the bomb hit the slope.
Snowpack Summary
Up to 35 cm thick storm slabs overlies previous windslabs on polar aspects and suncrusts on solar aspects, with rain saturated snow below 1800m. Solar slopes will have a new crust up to 1900m.
Several buried crusts can be found in the top 50-60 cm on solar aspects. The November depth hoar at the base of the snowpack remains a concern only in shallow areas of the Yoho sub-region.
Weather Summary
Thursday: Partially cloudy skies through the day and as much as 10cm's of snow from Wednesday evening through to the end of the day Thursday. There is a small chance of a thunderstorm Thursday afternoon as well. Winds will be light and freezing levels will be between 1600-1800m, with the alpine high between +2 and -3.
Friday: Cloudy skies with convective activity through the day on Friday. A chance of thunderstorms is mentioned in forecast's again. Freezing levels will be higher, between 1700-2000m and the winds will increase into the moderate range.
Problems
Storm Slabs
Up to 40cm of storm snow has fallen and has created widespread storm slabs in alpine and tree-line areas. The storm snow will need several days to settle and bond. In the alpine wind will have contributed to making the storm slabs even thicker.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
The November basal facets at the base of the snowpack have been mainly dormant in this region. This new load (of snow above 2000m and rain below) will be a good test on this layer. There is some uncertainty as to whether this layer will "wake up" in the Yoho region.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Loose Wet
Largely out of extreme rocky terrain, on solar aspects.
Aspects: South East, South, South West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Apr 13th, 2023 4:00PM
