Avalanche Forecast
Issued: Dec 14th, 2020 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.
jfloyer,
Avalanche Canada
Expect wind slabs to develop in exposed areas, especially on Wednesday as we see some new snow and strong winds.
Summary
Confidence
Moderate - Confidence is due to a stable weather pattern with little change expected. Uncertainty is due to the fact that deep persistent slabs are particularly difficult to forecast.
Weather Forecast
MONDAY NIGHT: Dry or light flurries. Treeline temperatures around -10 C. Moderate ridgetop winds southwesterly around 40 km/h.
TUESDAY: Flurries. Treeline temperatures around -8 C. Moderate ridgetop winds southwesterly around 40 km/h.
WEDNESDAY: Around 10 cm new snow. Treeline temperatures around -5 C. Strong ridgetop winds southwesterly 50-70 km/h.
THURSDAY: Around 10 cm new snow. Treeline temperatures around -10 C. Light northwesterly winds.
Avalanche Summary
No recent slab avalanche have been observed in this regions.
Snowpack Summary
Snow depths are approximately 150 cm around Pine Pass, Torpy and McBride and around 100 cm in the northeast around Tumbler Ridge.Â
The alpine is heavily wind-affected and lower elevations are capped by a hard crust up to around 1300 to 1600 m. Sheltered areas at treeline may still have 5 to 20 cm of soft snow on the surface.Â
A widespread crust layer that may have sugary faceted grains above it can be found at the bottom of the snowpack. Uncertainty remains about if and where this layer is a problem. Recent observations from the McBride area suggest the snow is well-bonded to this crust. Observations from around Tumbler ridge suggest ongoing concern for this layer in this zone. I suspect the layer to be potentially reactive in northern parts of the region, such as Pine Pass, but do not have observations to back this up.Â
Terrain and Travel
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Avoid thin areas like rock outcroppings where you're most likely to trigger avalanches failing on deep weak layers.
Problems
Wind Slabs
Triggering wind slab avalanches remains possible at higher elevations, especially on freshly wind-loaded terrain features. New wind slabs are likely to form during periods of strong wind on Monday.
Aspects: North, North East, East, South East.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Deep Persistent Slabs
We are uncertain about where the early-November crust has weak faceted grains above it, and if this layer remains as a problem. Our limited information suggests this problem is more likely found around Pine Pass and the eastern slopes of the Rockies. Given our lack of field observations, the prudent choice is to approach any big open slope with caution, especially slopes that are rocky and have variable snowpack depths.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2020 4:00PM
