Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Cooler temperatures & light snow will moderate the avalanche danger on Thursday. As conditions show signs of improving, be careful venturing out into bigger terrain unless it has already avalanched. The surface snow may feel stable, but the deep weak persistent layers remain a concern. Skies clear on Friday elevating the hazard.
Confidence
Moderate
Avalanche Summary
Lake Louise snow safety explosive tested some lesser worked northerly alpine terrain today. Although the shot didn't release an avalanche, it remoted a slope 40 m away, causing a size 2, 60-80 cm deep.
Snowpack Summary
At upper elevations, on northerly aspects, up to 30 cm of recent snow overlies a supportive snow surface or the prominent March 27 rain crust, which formed in last week's rain event. On southerly aspects, there are few additional crusts near the surface.
Below this, a 70 cm slab of dense snow overlies another 70 cm of weak facets. Test results continue to show weakness and propagation in this layer. This is the main event in the snowpack that should dominate decision-making.
Weather Summary
A few flurries Wednesday night with up to 5 cm expected. On Thursday, a ridge of high pressure builds with clearing skies through the day and light northerly winds. Another warm-up begins on Friday for the weekend, with freezing levels climbing to 2300 m by Saturday. Skies will be generally clear on Friday and Saturday. Warmer temperatures and solar input will bump up the hazard on Friday and Saturday.
Terrain and Travel Advice
- Be mindful that deep instabilities are still present and have produced recent large avalanches.
- Give the new snow several days to settle and stabilize before pushing into bigger terrain.
Avalanche Problems
Persistent Slabs
A 60-100cm slab of dense snow sits atop the persistent mid-pack facet layer from Jan/Feb. In thin snowpack areas weak depth hoar extends to the ground. There has been lots of large avalanche activity on this facet layer, and where it hasn't avalanched, triggering this layer remains a big concern.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible
Expected Size: 1.5 - 3