Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Sunshine, West Side 93N.
Natural activity is tapering off, but uncertainty remains high. Approach terrain decisions with intention and allow for a margin of error.
Avalanche control is being conducted on Mt Stephen on Mar 31, 2025. This area will be closed.
Confidence
Moderate
Avalanche Summary
The Parks Canada field team was up 93N today. Evidence of the recent avalanche cycle remain, but all observed slides are 24 hours old or older. Sunshine patrol reported a natural loose wet cycle to size 2. These slides were storm snow running on a crust. This is something to watch out for on Monday if the sun comes out.
Snowpack Summary
30cm of settled of storm snow over the past 3 days with the most in the Banff/Kootenay areas of the region. This new snow overlies rain and temperature crusts up to ~2500 m. A 50-100+ cm dense slab now sits over a persistent weak layer of facets from Jan/Feb. In Eastern areas with a thinner snowpack, these weak facets and depth hoar extend to the ground. In thicker snowpack regions west of the divide, the facet layer is not as pronounced and the lower snowpack is more settled.
Weather Summary
Light southerly winds will persist through Monday. Temperatures will remain seasonal or slightly cooler, with valley highs just above zero in the afternoon and ridge temperatures near -9°C. A minor system is expected to bring less than 5 cm of precipitation late Monday into early Tuesday.
Terrain and Travel Advice
- Uncertainty is best managed through conservative terrain choices.
- 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 60-100+ cm slab of dense snow now 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 a lot of large avalanche activity on this facet layer, and where it hasn't avalanched, triggering it remains a major concern.
Aspects: All aspects.
Elevations: All elevations.
Likelihood: Possible - Likely
Expected Size: 1.5 - 3.5
Storm Slabs
Up to 30cm of settled of storm snow buries previous crusts and winds slabs. The new snow could fail as a storm slab in steep terrain, and has potential to step down to deeper weak layers in the snowpack. Any significant solar inputs on Monday will increase the likelihood of these slabs being triggered.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood: Possible - Likely
Expected Size: 1 - 2
Loose Wet
This problem is driven by air temperature and solar input. The latest storm snow sits on a crust and could slide easily if conditions warm, especially under strong sun. Heat and solar input remain uncertain in the models, so monitor conditions closely at the local level on Monday.
Aspects: South East, South, South West, West, North West.
Elevations: All elevations.
Likelihood: Possible
Expected Size: 1 - 2