Avalanche Forecast
Issued: Nov 29th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
ahanna,
Avalanche Canada
With little field data available, uncertainty around conditions is best managed through a conservative approach. Ease into terrain cautiously on Tuesday and watch for signs of instability.
Summary
Confidence
Weather Forecast
Monday night: Flurries, up to 5 cm. Moderate southwest wind. Freezing level 1700 m.
Tuesday: Flurries, up to 5 cm. Strong southwest wind. Freezing level 1800 m.
Wednesday: Wet snow and rain, 10-30 mm. Strong southwest wind. Freezing level 2500 m.
Thursday: 5-15 mm rain turning to snow overnight then clearing. Moderate southwest wind. Freezing level dropping 2000 to 1700 m.
Avalanche Summary
Several natural storm slab avalanches were observed in the alpine on Sunday, a few notably stepping down to deeper layers (suspect the mid November crust).
A natural avalanche cycle occurred overnight Thursday-Friday, large storm slab avalanches (size 2-2.5) in alpine and upper treeline features were reported Friday morning. Through the day, explosives triggered large (size 2) storm slab avalanches.
Snowpack Summary
The upside-down upper snowpack consists of a 10-15 cm heavy, wet cap sitting over about 40 cm of lower density snow. Below lies a thick mid-November rain crust which has been the suspected bed surface of a few recent step-down avalanches. Moist snow is still found below the crust and to the ground.
Snowpack depths range from 40-70 cm at treeline elevations. Expect to find a deeper snowpack at higher elevations and in wind-loaded areas. Snowpack depths decrease rapidly below 1500 m.
Terrain and Travel
- Uncertainty is best managed through conservative terrain choices at this time.
- Make observations and assess conditions continually as you travel.
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Be aware of the potential for large avalanches due to the presence of a buried crust.
Problems
Storm Slabs
Storm slabs may remain reactive amidst sustained warm temperatures. Heavy, wet storm slabs sitting on top of lower density snow also has potential for step-downs to the mid November crust.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Nov 30th, 2021 4:00PM
