Avalanche Forecast
Issued: Mar 23rd, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Loose Dry and Deep Persistent Slabs.
trettie,
Avalanche Canada
Continue to practice good group management, high mark or ski steep slopes one at a time and minimize time below cornices.
Summary
Confidence
Avalanche Summary
Over the past few days wet loose avalanches up to size 3 and natural cornice falls up to size 2.5 were reported throughout the region. One of these large wet loose avalanches triggered a deep persistent slab avalanche at 2600 m. The crown was up to 2 m deep.
Snowpack Summary
Up to 10cm could overlie a crust on solar aspects and all aspects treeline and below. On high north facing terrain this new snow will overlie surface hoar.
30-50 cm down there is a sun crust on sunny aspects and surface hoar (3-10 mm) on isolated shady and sheltered slopes.
The mid-snowpack is generally strong but the lower snowpack is a different story. The November facets are still prominent at the base of the snowpack. They are showing signs of improving but this layer remains a significant concern for human triggering in rocky, shallow, or thin-to-thick snowpack areas at treeline and above. Small avalanches and cornice falls also have the potential to trigger this deep layer.
Weather Summary
Thursday Night
Increasing cloud with up to 10 cm of new snow expected. Light southerly winds and a Low of -7°C at 1800 m.
Friday
Mostly Cloudy with the possibility of light flurries bringing up to 5 cm of new snow. Light southwest winds and a High of -4°C at 1800 m.
Saturday
Mostly cloudy with the possibility of convective flurries bringing up to 5 cm of new snow. Light westerly winds and a high of -4°C at 1800 m.
Sunday
Mostly cloudy with the possibility of flurries bringing up to 5 cm of new snow. Light northeast winds and Freezing levels rising to 1600 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- In areas where deep persistent slabs may exist, avoid shallow or variable depth snowpacks and unsupported terrain features.
- Avoid sun exposed slopes when the solar radiation is strong, especially if snow is moist or wet
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
- Minimize your exposure time below cornices.
Problems
Loose Dry
New snow may not bond well to the underlying surfaces. Use caution on steep slopes where loose avalanches are more possible.
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 cornice failures or smaller avalanches in motion have the potential to produce very large avalanches with surprisingly wide propagation. Suspect terrain for human triggering includes steep, shallow, and rocky terrain where the snowpack transitions from thin to thick.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Mar 24th, 2023 4:00PM
