Avalanche Forecast
Issued: Mar 29th, 2021 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Cornices.
ahanna,
Avalanche Canada
Storm slabs may remain reactive to human triggers as natural avalanche activity tapers off. Start with small terrain features, look for sign of instability and gather information before considering bigger terrain.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength. Uncertainty is due to rapidly fluctuating freezing levels.
Weather Forecast
Monday night: Scattered flurries. Moderate northwest wind. Freezing level valley bottom. Alpine temperature -13.
Tuesday: Scattered flurries. Moderate westerly wind. Freezing level 1400 m. Alpine temperature -7.
Wednesday: Sunny. Light to moderate southwest wind. Freezing level 1800 m. Alpine temperature -1.
Thursday: Flurries. Strong southwest wind. Freezing level 1700 m. Alpine temperature -3.
Avalanche Summary
We are still awaiting reports of avalanche activity from the weekend's storm. A widespread natural cycle is likely to have occurred Sunday.Â
On Saturday, evidence of an old size 2 cornice failure was observed at Allen Creek. Otherwise, we have no reports of avalanche activity since Wednesday's storm when there were a few reports of natural and human triggered storm slab avalanches.
Snowpack Summary
The weekend's storm dropped 20-50 cm of new snow over the region. This snow came with wind from southwest to northwest, loading thick slabs in lee features at upper elevations. The new snow is expected to bond reasonably well with underlying surfaces. Crusty and/or moist surfaces exist below treeline depending on elevation and time of day.
The new snow buries old stubborn slabs at upper elevations and a crust below treeline. Recent warm weather patterns are expected to have helped old persistent weak layers heal. The new snow load (and whether it triggers deeper slabs during the storm) may help shed some light on concerns over a facet layer 150 cm deep from the mid-February cold snap that resulted in few large cornice triggered avalanches in the first half of March.
Terrain and Travel
- Keep in mind that human triggering potential persists as natural avalanching tapers off.
- Start with conservative lines and watch for clues of instability.
- Seek out sheltered terrain where new snow hasn't been wind-affected.
- Use extra caution around cornices: they are large, fragile, and can trigger slabs on slopes below.
Problems
Storm Slabs
Storm slabs may remain reactive to human triggers in wind loaded terrain features. Wind direction has varied from southwest to northwest so watch for these deep pockets on a variety of aspects.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Cornices
Cornices are likely fragile due to rapid growth with recent snow and wind.
Aspects: North, North East, East, South East.
Elevations: Alpine.
Likelihood
Expected Size
Valid until: Mar 30th, 2021 4:00PM
