Avalanche Forecast
Issued: Jan 2nd, 2024 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs and Deep Persistent Slabs.
rgoddard,
Avalanche Canada
Conservative terrain choices will be your best tool to work the problem of uncertainty around buried weak layers.
Summary
Confidence
Moderate
Avalanche Summary
On Sunday, a skier was uninjured after accidentally triggering a size 2 deep persistent slab on basal facets over a smooth rock slab.
Ongoing explosive control work in recent days has consistently produced deep persistent slab avalanches, size 1.5 to 2.
Snowpack Summary
Small amounts of new snow rests on old surfaces including surface hoar, facets, and crusts. Beneath lies a complex snowpack with several layers of concern.
The most prominent is a layer of surface hoar buried 20 to 50 cm deep. It is less of a concern in areas where a strong, supportive crust exists above this layer.
The mid to lower snowpack is typically characterized by sugary, facetted crystals and a basal crust.
Snowpack depths at treeline range from 50 to 130 cm.
Check out this blog post for some insight into the current shallow yet complex snowpack.
Weather Summary
Tuesday Night
Mostly clear with some clouds, potential trace accumulation, ridgetop winds south 15 km/h, treeline temperature -7 °C.
Wednesday
Mix of sun and clouds, trace accumulation, ridgetop winds south 20 km/h, treeline temperature -6 °C.
Thursday
A mix of sun and cloud, 2 cm accumulation, ridgetop winds south-southwest 15 km/h, treeline temperature -7 °C.
Friday
Cloudy with late-day clearing, 2 cm accumulation, ridgetop winds southwest 10 km/h, treeline temperatures -8 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices at this time.
- Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
- Avoid shallow snowpack areas, rock outcroppings and steep convex terrain where triggering is most likely.
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
Problems
Persistent Slabs
A layer of surface hoar is buried 20 to 50 cm deep. If triggered, avalanches on this layer could step down to deeper weak layers.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
A layer of weak facets near the ground may be reactive to human triggering, especially in shallow, rocky areas in alpine terrain where a crust cannot be found above the layer.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Jan 3rd, 2024 4:00PM
