Regions
Banff Yoho Kootenay.
While avalanche activity is tapering, give wide margin to steep, open and planar features.
Weather Forecast
Cold temperatures will persist in the forecast region for another few days. Expect lows in the -20 range. Very light precip is expected over the next 3 days, 2-5cm, which is not enough to effect the danger ratings. Wind velocity will be reasonable, generally light to moderate from the N-NW.
Snowpack Summary
Windslabs are common in open areas in the alpine, however the cold temps are making them considerably less touchy. A deep slab overlies midpack weaknesses of surface hoar, crusts, and facets. The depth of these slabs varies from 75 cm to 150 cm. These layers have been producing very large avalanches over the past week.
Avalanche Summary
No new avalanches were reported or observed today. Natural activity has been tapering off, but potential still exists.
Confidence
Due to the number of field observations on Sunday
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.
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.