Avalanche Forecast
Issued: Dec 28th, 2023 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs, Wind Slabs and Persistent Slabs.
jpercival,
Avalanche Canada
When rainfall begins on new snow, expect the danger rating to be at High.
Choose terrain that is not exposed to overhead hazard and seek low angle slopes, especially as temperatures increase.
Summary
Confidence
Avalanche Summary
On Tuesday, explosive avalanche control produced large avalanches up to size 2.5 within the recent storm snow, with crowns as deep as 75 cm.
On Monday, a natural avalanche cycle up to size 2.5 was reported during the storm.
If you head into the backcountry please consider submitting your observations to the Mountain Information Network!
Snowpack Summary
Snowfall amounts from the recent storm range from 50 to 100 cm. At elevations below 500 m a thick 10 cm crust is found at the surface.
At upper elevations, strong southerly winds have formed deep wind slabs in leeward terrain, while scouring windward slopes.
A spotty layer of surface hoar can be found down over 100 cm in sheltered terrain features at and below treeline. The distribution of this layer is not well known, and it may be getting too deep to be triggered by the weight of a human.
A layer of facets buried at the end of November can be found near the ground. The snowpack depth varies between 200 and 300 cm at treeline.
Weather Summary
Thursday Night
Cloudy with snow flurries, 5-15 cm. Moderate to strong southeast wind. Treeline temperatures around -3 °C. Freezing level 500 m.
Friday
Cloudy with snowfall 10-20 cm, turning to rain below 1300 m. Moderate to strong southeast wind. Treeline temperatures around -1 °C. Freezing level 1500 m.
Saturday
Cloudy with snow flurries 5-10 cm. Moderate to strong southeast wind. Treeline temperatures around -1 °C. Freezing level 1500 m.
Sunday
Daytime clearing with possible light flurries. Trace amounts of new snow. Moderate south west wind. Treeline temperature -10 °C. Freezing level 200 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- The first few hours of rain will likely be the most dangerous period.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Stay off recently wind loaded slopes until they have had a chance to stabilize.
Problems
Storm Slabs
In areas where precipitation in the form of rain is greater than 30mm expect Storm slabs to be touchy. Loose wet avalanches are likely on steep thin rocky areas.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Wind Slabs
50-100 cm of recent snow has been blown into deep wind slabs by strong winds. Recent winds have shifted from southwest to southeast, so watch for wind slabs on a variety of aspects.
Aspects: North, North East, East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
A deeply buried layer of facets sitting on a hard crust 100-200 cm below the snow surface is likely unreactive. It may be triggered from a thin spot or by a very heavy load such as a cornice failure.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 29th, 2023 4:00PM
