Avalanche Forecast
Issued: Dec 11th, 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
Continue to keep an eye out for signs of instability and assess the bond between recent snow and the underlying surface. Surface hoar may be lurking in sheltered terrain at treeline.
Summary
Confidence
Avalanche Summary
On saturday a few natural size 1 wind slabs were observed in the north of the forecast region. These avalanches were in immediate lee features as a result of easterly winds.
On Friday a few small natural cornice falls and a few wind slab avalanches up to size 2 were observed on west facing slopes in the region.
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 80 to 120cm 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.
In the alpine snowpack depths up to 3 meters have been reported but the snowpack below treeline is still generally quite shallow.
Weather Summary
Sunday Night
No new snow expected. Moderate outflow winds. Temperature inversion starting with a high of -5 at 1500m.
Monday
A mix of sun and cloud with the possibility of light flurries in the afternoon bringing trace amounts of new snow. Moderate outflow winds continue. Temperature inversion with temperatures reaching a high of -2 at 1500m.
Tuesday
Mostly cloudy with flurries bringing trace amounts of new snow to the terrace area and around 5cm for more northern areas. Temperature inversion with a high of -5 at 1500m. Light to moderate southwest winds.
Wednesday
A mix of sun and cloud with light flurries possible bringing trace amounts of new snow. Outflow winds return. Temperature inversion continues with a high of -3 at 1500m.
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.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
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 12th, 2022 4:00PM
