Avalanche Forecast
Issued: Dec 10th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs.
trettie,
Avalanche Canada
Carefully assess the bond between recent snow and the underlying surface. Variable winds have likely formed wind slab on all aspects. These slabs could be larger and more reactive at treeline where they might sit over surface hoar.
Summary
Confidence
Avalanche Summary
On Friday a few small natural cornice falls and a few wind slab avalanches up to size 2 were observed on lee features in the region.
Numerous natural storm slabs and loose dry avalanches, to size 2, were reported Thursday at all elevations. Avalanches are suspected to have released on the recently buried surface hoar layer.
If you head out in the backcountry please support your community by submitting a MIN report!
Snowpack Summary
30 to 50cm of storm snow has been redistributed into wind slabs on all aspects by variable winds. This recent snow overlies a layer of surface hoar, size 5-10 mm, and facets. Surface hoar overlies wind-hammered surfaces including scoured easterly slopes and hard slabs on west and south slopes.
A layer that formed in mid-November can be found down 70 to 100 cm deep at treeline and above. This layer consists of a crust below 1200 m and a layer of surface hoar above this elevation. This layer has not shown recent signs of instability.
The depth of the snowpack at treeline varies widely from 100 to 200 cm and tapers rapidly below treeline. Many early-season hazards such as rocks, stumps, and open creeks exist below treeline.
Weather Summary
Saturday Night
Clearing throughout the night with no new snow expected. Moderate to strong outflow winds with a low of -12 at 1500m.
Sunday
Mostly sunny with cloudy periods. Strong outflow winds and temperatures around -11 at 1500m. Freezing levels valley bottom.
Monday
Mostly sunny with no new snow expected. Moderate outflow winds continue. Possible temperature inversion with temperatures reaching a high of -2 at 1500m.
Tuesday
Mostly cloudy with flurries bringing trace amounts of new snow. Temperature inversion breaking down throughout the day with a high of -4 at 1500m. Light to moderate southwest winds.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid open slopes and convex rolls at and below treeline where buried surface hoar may be preserved.
- Recent wind has varied in direction so watch for wind slabs on all aspects.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
Problems
Wind Slabs
20 - 30 cm of storm snow now sits atop a preserved layer of surface hoar/facets. As wind changes direction and redistributes snow into wind slab on all aspects backcountry users should be extra cautious at treeline where wind slabs could over lie the surface hoar mentioned above. Triggering one of these slabs could result in a larger and more destructive avalanche.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 11th, 2022 4:00PM
