Regions
Banff Yoho Kootenay.
Great skiing can be found and we are slowly gaining confidence in the snowpack. But given the Feb 10th layer is so widespread in the region and showing sudden results on South aspects, we recommend conservative, low consequence route choices.
Weather Forecast
Mix of sun and cloud for the weekend, highs of -10, and winds will be light westerly with occasional gusts. These weather inputs will not significantly affect the hazard rating and we should see a gradual improvement in the avalanche hazard.
Snowpack Summary
5-10 new overnight, a thin sun crust on steep solar aspects. In the Lake Louise region, field tests on south aspects, the Mar 2nd suncrust/facet layer, down 40 cm, and the Feb 10 crust/facet, down 80 cm, produced moderate to hard sudden failures with the potential to propagate, Fewer results on North aspects.
Avalanche Summary
There was one size 2.5 explosive controlled avalanche in Lake Louise area, slid to ground, N aspect, previously controlled terrain. One size 1 sluff observed out of steep rocky terrain NW aspect. Watch out for natural activity related to solar heating over the weekend. Earlier this week, there was a cornice triggered size 3 in the Sunshine region.
Confidence
Due to the number of field observations
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.
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.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.