Avalanche Forecast
Regions: Banff, Banff Yoho Kootenay, East Side 93N, Field, Kootenay, LLSA, Lake Louise, Little Yoho, Sunshine, West Side 93N.
A short return to winter has given us 5-15 cm of new snow, depending on location. Just enough for a refresh, although the spring crust is just under the surface. The next few days look good as the skies clear and temperatures remain cool with north winds, then the next spring warm-up happens through the weekend and into next week.
Confidence
Moderate
Avalanche Summary
Thin (5-10 cm) and soft windslabs and sluffs to size 1 were easily triggered today on open slopes from new snow and wind loading. The cool temperatures have temporarily slowed down the deeper avalanche activity, but expect this to spike up again when it warms up or gets direct sun. During the last warm spell, many avalanches stepped down to the Feb. 3/basal facet layer (See photos). These were a combination of solar triggered or cornice triggered on polar aspects.
Snowpack Summary
5-10 cm of new snow now covers previous surfaces of crust and wind effect. Small windslabs have formed in isolated areas above treeline and will react easily to human triggers since they're on a smooth crust - but the avalanches are small. The midpack is well settled down to the Feb 3 persistent weak layer which remains a concern in shallow snowpack areas on northerly alpine aspects. In these areas, no crusts are found in the upper snowpack and the midpack remains thin and weak.
Weather Summary
Tuesday's storm will end overnight and clearing arrives on Wednesday, setting up for a week of mostly sunny and slowly warming weather ahead. Wednesday will remain mostly cool except in the direct sun with freezing levels at 1600 m and moderate N winds keeping the snow cold. Then look for gradual warming starting Friday and with warm spring weather ahead next week.
Terrain and Travel Advice
- Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
- Loose avalanches may start small but they can grow and push you into dangerous terrain.
Avalanche Problems
Wind Slabs
Recent snow and wind have created thin windslabs in isolated pockets at higher elevations, along with some loose snow avalanches in gullies as well. These are small avalanches but could knock you off your feet in steep terrain and should be expected to become active when the sun comes out.
Aspects: All aspects.
Elevations: Alpine.
Likelihood: Possible
Expected Size: 1 - 1.5
Persistent Slabs
The cool weather has temporarily reduced the likelihood of triggering this problem, but expect it to wake up again within a few days as it warms up. The Feb 3 layer is down 60-130 cm. In shallow snowpack areas on northerly alpine aspects, this layer will again be sensitive to skiers.
Aspects: North, North East, East, North West.
Elevations: Alpine.
Likelihood: Unlikely
Expected Size: 2 - 3