Regions
Banff Yoho Kootenay.
Winds still seem to be honking in the high alpine. With up to 30cm of new snow west of the Divide, the new windslabs in the alpine will be touchy to human-triggering.
Weather Forecast
A ridge of high pressure should bring mainly clear skies for the morning, with increasing clouds later in the day. Winds will drop to light from the west. No new snow is forecasted for the region until possibly Friday evening. Temp's will be near seasonal values in the alpine (-10*C).
Snowpack Summary
Strong westerly winds in the last 12 hours have formed fresh windslabs in alpine lee terrain. We received 10-15cm up the Icefields Parkway, but closer to 25-30cm west of the Divide in Little Yoho Valley. Where shallow the mid-pack is weak and facetted. West of the divide the mid-pack remains strong due to a deeper snowpack.
Avalanche Summary
Several size 1.5 loose avalanches were observed from steeper alpine features in the Little Yoho Valley. No recent avalanches observed up the Icefields Parkway, but large plumes of wind-transported snow observed off ridge crests.
Problems
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.