Avalanche Forecast
Issued: Mar 8th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Deep Persistent Slabs.
rgoddard,
Avalanche Canada
Solar input this time of year can have a huge effect on the snowpack. Avoid solar slopes during the heat of the day.
Triggering large slab avalanches remains possible in steep, rocky, and wind-affected areas.
Sheltered and shaded terrain will offer the best and safest riding.
Summary
Confidence
Moderate
Avalanche Summary
Monday and Tuesday saw periods of intense solar input. This caused several cornices to fail. These occurred in the alpine and the impact that some of them had on the slopes below, caused the slope below them to avalanche.
Helibombing on Monday was able to trigger the deep persistent slab, creating avalanches up to size 4. These were in the alpine and the layer that was released was typically 150 cm down.
Over the weekend, a few natural and skier-triggered wind slabs (size 1 to 2) were reported from south, southwest, and east-facing alpine terrain as northerly winds impacted the region. One large (size 2.5) deep persistent slab was triggered by a cornice failure in very steep north-facing alpine terrain.
Snowpack Summary
A sun crust can be found on steep south-facing aspects. Surface hoar growth has been reported in sheltered areas. Shifting winds have redistributed last week's storm snow into wind slabs on a variety of aspects. This storm snow sits over wind-affected surfaces and a thin sun crust on steep south-facing slopes.
The mid-snowpack is generally well-settled and strong.
The November facets are still prominent at the base of the snowpack. Although this layer is showing signs of rounding, there is a significant difference in resistance between it and the overlying snow. These facets are most pronounced in shallow rocky areas.
Weather Summary
Wednesday Night
Clear, no accumulation, winds easterly 10 to 15 km/h, treeline temperatures around -10 °C.
Thursday
Sunny, no accumulation, winds southeast 10 to 15 km/h, treeline temperatures -10 to -5 °C.
Friday
A mix of sun and cloud, trace accumulation, winds northeast 25 km, treeline temperatures around -10 °C.
Saturday
A mix of sun and cloud, trace accumulation, winds easterly 10 to 20 km/h, treeline temperatures -12 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Minimize exposure to sun-exposed slopes when the solar radiation is strong.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
Problems
Wind Slabs
Variable winds over the past week mean that wind slabs could be found on all aspects. Keep your guard up as you enter wind-affected areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A weak layer of facets exists near the base of the snowpack. The likelihood of human triggering is low given the layer's depth, but large triggers such as smaller avalanches in motion or cornice failures have the potential to produce very large avalanches with wide propagation. Suspect terrain for human triggering includes steep, shallow and rocky terrain.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 9th, 2023 4:00PM
