Regions
Banff Yoho Kootenay.
The story to watch for Friday is all about the wind. When will the wind come up? When it does, the avalanche danger will quickly rise to CONSIDERABLE. Until then - enjoy the totally amazing conditions that this unusual storm has brought to the park.
Weather Forecast
The same weather pattern of light snow, cold temperatures and light wind continues until mid-day on Friday. Friday afternoon looks to be when the wind speed will increase (possibly up to 50km/hr at 3000m) and the temperatures will rise a few degrees. By Saturday another pulse of snow (with wind) will arrive - expect another 10cm at Bow Summit.
Snowpack Summary
Over 40 cm of snow has fallen in the Sunshine, Bow Summit and Lake Louise areas since Wednesday. This snow has fallen with no wind, and there is no slab formed in the surface snow - just 40 cm of fluff. This will change within hours when the wind starts to blow or the sun comes out, so watch for this critical change to begin on Friday afternoon.
Avalanche Summary
No new slab avalanches observed or reported today, but several loose snow avalanches (sluffs) up to size 2 were noted.
Confidence
Wind speed and direction is uncertain on Friday
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
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.