Avalanche Forecast
Issued: Dec 15th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
bchristie,
Avalanche Canada
Choose terrain carefully, and investigate for signs of instability and a buried layer of weak surface hoar.
The weight of a rider could cause a surprisingly large avalanche on this layer.
Summary
Confidence
Moderate
Avalanche Summary
No new avalanche reports were submitted on Friday. This MIN post from our North Rockies field team talks about signs of instability due to buried surface hoar layers, and how that influenced their choice of riding terrain.
If you go out in the backcountry, please consider sharing your observations on the Mountain Information Network (MIN).
Snowpack Summary
5-10 cm of new snow arrives with strong southwest wind, likely forming thin, reactive pockets of windslab over old, hard surfaces. Previously, strong to extreme wind stripped available snow from south and west-facing slopes, which formed stiff, unreactive windslabs on north and east-facing terrain features.
A concerning layer of weak, feathery surface hoar crystals can be found around 30-50 cm deep.
A crust with sugary facets beneath it can be found just above the ground. The snowpack is still shallow for this time of year. Average snowpack depths at treeline range from 40 to 75 cm.
Weather Summary
Temperatures may be colder west of pine pass.
Friday Night
Cloudy. 5-10 cm of snow expected to valley bottom. Strong southwest ridgetop wind. Treeline temperature around -5°C.
Saturday
Cloudy morning, sunny afternoon. No new snow expected. Moderate to strong southwest or west ridgetop wind. Treeline temperature around -8°C. Freezing level around valley bottom.
Sunday
Mostly cloudy. 0-2 cm of snow expected. Strong to extreme southwest ridgetop wind. Freezing levels rising to 1500 m.
Monday
Mostly cloudy. 2-5 cm of snow expected. Wind decreasing to light southeast by the end of the day. Freezing level 1000-1500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
- Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
- Be aware of the potential for larger than expected storm slabs due to the presence of buried surface hoar.
Problems
Persistent Slabs
Buried surface hoar is most likely to be found at treeline and above. It's most triggerable where the buried rain crust is thinner and less supportive, or absent.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 16th, 2023 4:00PM
