Avalanche Forecast
Issued: Mar 7th, 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.
zryan,
Avalanche Canada
The air is cold but the March sun can be strong so avoid exposure to cornices and steer well clear of steep south aspects during periods of strong sun. Sheltered and shaded terrain will offer the best and safest riding.
Triggering large slab avalanches remains possible in steep, rocky, and wind-affected areas.
Summary
Confidence
Moderate
Avalanche Summary
With periods of strong sun on Monday, two natural cornice failures occurred (size 1-2), one pulled a storm slab on the slope below.
Over the weekend, a few natural and skier-triggered wind slabs (size 1-2) 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
On the surface, a sun crust can be found on steep south-facing aspects and 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. They are showing signs of rounding but there is still a considerable step in resistance between them and the overlying snow. These facets are most pronounced in shallow rocky areas.
Weather Summary
Tuesday night
Clear with cloudy periods. Alpine temperatures drop to a low of -10 °C. Ridge wind light from the southeast. Freezing level at valley bottom.
Wednesday
Mainly sunny. Alpine temperatures reach a high of -7 °C. Ridge wind light from the east. Freezing level rises to 600 meters
Thursday
Sunny with cloudy periods. Alpine temperatures reach a high of -8 °C. Ridge wind light from the southeast. Freezing level rises to 600 meters.
Friday
A mix of sun and cloud. Alpine temperatures reach a high of -7 °C. Ridge wind light from the northeast. Freezing level rises to 400 meters.
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 8th, 2023 4:00PM
