Regions
Banff Yoho Kootenay.
Forecasted snowfall amounts are uncertain. Be observant of storm snow accumulations at the local level and watch for the development of storm slabs.
Weather Forecast
Up to 20cm of storm snow is expected to fall across the forecast region tomorrow. Likely, by 9am tomorrow the storm will start to taper off and then build again Weds night. The storm snow will elevate the hazard to considerable on Tues. Steady precip is expected throughout Weds/Thurs. Added load on Thurs/Fri will raise the danger rating to high.
Snowpack Summary
30-60cm of storm snow with little wind effect is bonding well. E of the divide, the Mar 13 sun-crust/facet layer is down 30-60 cm on S aspects, and the Feb 10 crust/facet layer is down 60-100cm and still whumphing in thin areas. W of the divide, the Feb 10 is deeper (80-150cm) and less reactive.
Avalanche Summary
No new avalanches observed or reported today in the forecast region. However, a few large skier triggered avalanches in the Columbias and K-Country over the last couple days indicate that the weak layers still exist and can be triggered by humans in specific areas.
Confidence
Intensity of incoming weather systems is uncertain on Thursday
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.