Avalanche Forecast
Issued: Nov 27th, 2024 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.
Avalanche Canada,
Avalanche Canada
Wind slabs and a deep persistent slabs continue to be reactive to rider triggers. Start conservative and watch for signs of instability like cracking or whumpfing.
Summary
Confidence
Low
Avalanche Summary
The deep persistent slab was reactive to rider triggers up to size 1 on Tuesday below treeline.
Last weekend, numerous natural and human-triggered persistent slab avalanches (up to size 2.5) were observed near Invermere. These primarily occurred on north through southeast aspects at treeline and above.
Smaller wind slab avalanches could step-down to the basal facets, initiating a larger slab avalanche.
Snowpack Summary
Up to 15 cm of new snow fell over the weekend. In wind-exposed areas cracking and whumping have been reported.
Down 30 to 40 cm sits a layer of surface hoar primarily found on shaded slopes, or on a thin crust on sunny slopes.
A crust exists near the bottom of the snowpack. This crust may have weak, sugary facets above and below it. Large avalanches failed on this layer last weekend.
Snowpack depths are reported to be 50-70 cm at treeline elevation.
Weather Summary
Wednesday Night
Cloudy with isolated flurries. 15 to 35 km/h west ridgetop wind. Treeline temperature -10 °C.
Thursday
Mix of sun and cloud. 10 to 30 km/h west ridgetop wind. Treeline temperature -9 °C.
Friday
Mix of sun and cloud. 15 to 30 km/h west ridgetop wind. Treeline temperature -10 °C.
Saturday
Mix of sun and cloud. 20 to 30 km/h west ridgetop wind. Treeline temperature -10°C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind-affected terrain.
- Be careful with wind-loaded pockets, especially near ridge crests and rollovers.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Wind Slabs
Fresh and reactive wind slabs may exist, especially at ridgeline and in exposed terrain features.
Aspects: North, North East, East, South East, South, South West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
Deep persistent slab avalanches have recently failed on weak faceted snow at the base of the snowpack. This problem is most likely found in the alpine and at treeline on smooth slopes.
Aspects: North, North East, East, South East, West, North West.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Nov 28th, 2024 4:00PM
