Avalanche Forecast
Issued: Mar 8th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Wind Slabs and Cornices.
astclair,
Avalanche Canada
Lingering wind slabs are the primary concern, particularly in the north of the region. Watch for denser, deeper drifts near ridge-crests and rollovers and give cornices a wide berth from above and below.
Summary
Confidence
Weather Forecast
Dry conditions and diurnal cycles for the next few days
Monday night: Mostly clear, light south winds, freezing level dropping to valley bottom.
Tuesday: Mix of sun and cloud, light southwest winds, freezing level rising to 1300 m and dropping to valley bottom overnight.
Wednesday: Partly cloudy, scattered flurries with trace accumulations, light variable winds, freezing level rising to 1000 m and dropping to valley bottom.
Thursday: Sunny, light variable wind, freezing level rising to 1200 m and dropping to valley bottom.
Avalanche Summary
In the north of the region, there have been several reports of small to large (up to size 2.5) storm slab avalanches releasing naturally on a variety of aspects and elevations during the weekend storm. One of these was thought to have been triggered by a cornice fall. Check out these MIN reports (here and here) from slopes near Chief Pascall. Small loose dry sluffs were also observed in steep terrain.
In the south of the region, there have been numerous reports of large (size 2-3) natural glide slab avalanches over the past week. Glide slabs are most likely in areas of smooth ground cover such as rock slabs and can be large, involving the full depth of the snowpack. Carefully consider your access/egress routes where they cross under large paths.
Snowpack Summary
In the north of the region, 30-50 cm of new snow over the weekend has been redistributed by strong south winds into wind slabs on leeward slopes that may remain possible to human trigger. Massive cornices exist on ridgelines, which can also act as triggers on slopes below. Deeper in the snowpack, a weak layer of facets buried in mid-February may still be found on north aspects near treeline but has been gaining strength. The lower snowpack is generally well settled and strong.
The south of the region received trace accumulations of snow over the weekend with moderate wind. The danger ratings are Moderate, Low, Low, with a concern for small wind slabs. The snowpack is generally well consolidated with no concerns of buried weak layers but recent notable glide avalanche activity.
Terrain and Travel
- Stay off recently wind loaded slopes until they have had a chance to stabilize.
- Avoid freshly wind loaded features, especially near ridge crests, roll-overs and in steep terrain.
- Watch for signs of instability like whumpfing, hollow sounds, shooting cracks or recent avalanches.
- Cornice failure may trigger large avalanches.
Problems
Wind Slabs
In the north of the region, 30-50 cm of snow has been redistributed by strong south winds into reactive wind slabs on lee features. Pay attention to the pattern of wind-drifting in the terrain where you are traveling and watch for cracking or changes in snow stiffness. Triggering large wind slabs on specific features remains possible.
Aspects: North, North East, East, South East, West, North West.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
In the north of the region, cornices have seen substantial growth since the last storm, and they may release naturally with the impact of solar radiation. Cornice falls can act as triggers on slopes below.
Aspects: All aspects.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 9th, 2021 4:00PM
