Avalanche Forecast

Archived

Mar 30th, 2025–Mar 31st, 2025

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Banff Yoho Kootenay, Banff, East Side 93N, Kootenay, Lake Louise, LLSA, Sunshine, West Side 93N, Field.

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.

Problems

Persistent Slabs

Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.

Storm Slabs

Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.

Loose Wet

Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.