Avalanche Forecast
Issued: Jan 15th, 2023 3:45PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs and Persistent Slabs.
JMackenzie,
Avalanche Canada
The lower half of the snowpack is still weak, and human triggering of large, destructive avalanches is still possible. Despite the MODERATE hazard rating, conservative terrain selection is still critical.
Summary
Confidence
High
Avalanche Summary
One size 2 slab was observed Saturday on the SE aspect of Hero's Knob at 2100m, possibly triggered by the warm temps. Nothing new was observed on Sunday.
Snowpack Summary
A couple of cm's of fresh snow overlies a very thin crust, but thankfully this crust disappears above 1900 to 2000m depending on the valley. A buried layer of surface hoar down 15 to 30cm at treeline continues to produce shears, but the main concern in the snowpack is the persistent moderate shears failing down 70 to 80cm in the mid-November facets. The lower half of the snowpack remains very weak, and any avalanche initiated in the upper snowpack will likely step down to the lower weaknesses. Thin and rocky areas are of particular concern for triggering the deeper weak layers. Below 2100m the snowpack does not support the weight of a skier if you leave an established skin track.
Weather Summary
Monday will be mainly cloudy with very light flurries in the morning. Snow accumulations should be near 2cm. Temps will climb to -5C by midday. Winds will be moderate from the SW, decreasing to light by late morning.
Tuesday will be cloudy and a little cooler.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid shallow, rocky areas where the snowpack transitions from thick to thin.
- Be aware of the potential for surprisingly large avalanches due to deeply buried weak layers.
- If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
Problems
Deep Persistent Slabs
Snowpack tests continue to indicate that human triggering of the deeper weak layers is a real possibility. Shallow rocky areas are particularly susceptible.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
If triggered the persistent slab is very likely to step down to the deeper instability and involve the entire winter's snowpack. Pay close attention at treeline where this layer is more commonly found.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 16th, 2023 4:00PM
