Avalanche Forecast
Issued: Dec 17th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs, Loose Wet and Wind Slabs.
trettie,
Avalanche Canada
745 Update: Investigate slopes at and above treeline for buried surface hoar before committing
Few observations in this region. We are unsure how this layer will react to warm weather
Summary
Confidence
Low
Avalanche Summary
No recent avalanches have been reported in the region. The buried surface hoar layers show continued reactivity in snowpack testing.
If you're heading out in the backcountry, please consider sharing any observations on the Mountain Information Network.
Snowpack Summary
Warm temperatures and sun may moisten the surface snow and break down crusts likely formed overnight. A widespread crust is buried around 10-20 cm deep, under wind affected snow.
At treeline and above, two layers of concern exist, buried around 30 and 50 cm deep. Both layers consist of a crust that tapers at higher elevations covered by a layer of fragile surface hoar in sheltered areas. No recent avalanche activity has been reported on these layers but they continue to be reactive in snowpack tests. These layers may become reactive to human triggers during the warming.
The snowpack remains shallow for the time of year. Snowpack depths at treeline range from 80 to 120 cm.
Weather Summary
Sunday Night
Partially clear with trace amounts of new snow possible, south alpine wind 20 to 40 km/h, above freezing layer above 1600 m.
Monday
A mix of sun and cloud with no new snow expected, south alpine wind 20 to 40 km/h, freezing level around 2500 m.
Tuesday
A mix of sun and cloud with trace amounts of mixed precipitation expected, southeast alpine wind 10 to 30 km/h, freezing level around 2200 m.
Wednesday
A mix of sun and cloud with trace amounts of mixed precipitation expected, south alpine wind 20 to 40 km/h, freezing level around 2100 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
- As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.
Problems
Persistent Slabs
Large surface hoar is buried 30-50 cm deep. Triggering this layer is most likely above 1900 m, and warm temperatures may increase reactivity. Investigate open slopes and convex rolls where buried surface hoar may be preserved.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Loose Wet
Warm temperatures in treeline combined with unexpected overnight precipitation may create a loose wet avalanche problem in snow that was previously dry.
Aspects: All aspects.
Elevations: Treeline.
Likelihood
Expected Size
Wind Slabs
Thin wind slabs may continue to be reactivein the alpine, especially where they sit over a crust or surface hoar.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Dec 18th, 2023 4:00PM
