Minimize overhead hazard and make conservative terrain choices on Sunday.
A warm, wet storm is moving through the region starting tonight. 15-30 cm of snow with strong to extreme W winds will bump the danger rating to HIGH in the alpine & CONSIDERABLE at treeline. This new load may also make the buried persistent layers more reactive.
New snow, warm temperatures and strong west winds are expected to form touchy new wind slabs at treeline and in the alpine that will be easy to trigger. Cornice failures may also occur. Minimize overhead hazard and avoid wind loaded slopes until the new snow has time to bond with the old surfaces.
A 40-80 cm slab sits over the Jan. 24th surface hoar layer on shady aspects, and crust/ facets on southerly slopes up into the alpine. The surface hoar has been most reactive in Yoho and Kootenay between 1600-2200m. This may become more reactive with the new load on Sunday.
No new avalanches were reported in these regions on Saturday, but visibility was limited.
Local ski areas were able to ski cut small wind slabs in the immediate lee areas of the alpine and treeline.
Moist snow reported below 1900 m.
Scouring, wind effect and some small wind slabs exist in the alpine. The Jan 24 persistent layer (surface hoar/crust/facet) is down 40-80 cm and remains reactive, producing variable results in the mod to hard range. This layer is most prominent at treeline and below, but concern for southerly aspects in the alpine also exists. We expect this problem to exist for the foreseeable future.
Sunday: Forecasts snow amounts vary with 10-35 cm of snow by the end of the day, with the larger amounts expected along the divide. Strong winds from the West continue through most of the day. Freezing levels stay near 2000 m Saturday night, and begin lowering through the day on Sunday.
Monday: Freezing levels drop to valley bottom, winds become light, and snow flurries with a mix of sun and cloud are expected.
