Avalanche Forecast
Issued: Apr 6th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Cornices and Wind Slabs.
astclair,
Avalanche Canada
Watch for cornices and reactive slabs in wind-drifted areas near ridgetops.
Summary
Confidence
Moderate - Uncertainty is due to the limited number of field observations.
Weather Forecast
Tuesday night: Clear, moderate southwest wind, treeline temperatures near 0 C, freezing level staying elevated at 2000 m.
Wednesday: Increasing cloud, isolated light afternoon flurries with trace accumulations, moderate southwest wind, treeline temperatures near -1 C, freezing level dropping from 1800 m to valley bottom.
Thursday: Mainly cloudy, 5-15 cm of snow, light west wind, treeline temperatures near -7 C, freezing level rising to 1500 m and dropping to valley bottom.
Friday: Increasing cloud, isolated flurries with trace accumulations, light southwest wind, treeline temperatures near -2 C, freezing level rising to 1600 m and dropping to valley bottom.
Avalanche Summary
On Monday and Tuesday, pinwheels and small loose wet avalanches were observed on steep sunny alpine slopes.
Snowpack Summary
Small wind slabs may be found on lee features below alpine ridgetops. Cornices are large, looming, and capable of triggering avalanches when they fail.
Sunny alpine slopes likely became moist on Tuesday afternoon. 5-15 cm of recent dry snow persists at upper elevations in shady north-facing terrain. Check out this MIN report for a helpful photo and description of the conditions from Mongolia Ridge.
The mid-pack is firm and well settled. Some faceted snow and a decomposing melt-freeze crust can be found near the base of the snowpack. Snow line is slowly creeping up the mountains to roughly 1400 m in elevation. Check out this MIN report for more details on the access from common staging areas.
Glide cracks releasing as full depth glide slab avalanches become more common in the spring and are extremely difficult to predict. Best practice is to avoid slopes with glide cracks.
Terrain and Travel
- Pay attention to cornices and give them a wide berth when traveling on or below ridges.
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Carefully evaluate steep lines for wind slabs.
Problems
Cornices
Cornices are large and looming along many ridgelines. They are capable of triggering large avalanches when they fail.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Wind Slabs
Small wind slabs may lurk on lee features below alpine ridgetops, formed by recent winds from the southwest.
Aspects: North, North East, East, South East, North West.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Apr 7th, 2021 4:00PM
