As you transition from melt-freeze conditions to dry snow, be on the lookout for wind-loaded pockets in lee features. And the possibility of wet loose avalanches will persist where snow is moist or wet.
At upper elevations where snow dry snow prevails, winds have redistributed dry snow forming pockets of wind slabs in lee features and below ridgelines. Expect new slabs to develop as the incoming storm brings flurries and more wind.
In the north of the region (e.g., Duffey Lake), a weak layer of sugary faceted grains around a hard melt-freeze crust sits near the base of the snowpack. Be wary of overhead hazards, a large impact (like a cornice failure) could trigger the slope below. There's a lot of uncertainty on the reactivity of this layer, however if this layer is triggered it will likely produce large avalanches. This problem does not exist in the south of the region.
SATURDAY NIGHT: Increasing clouds / Moderate, southwest ridgetop wind / alpine low temperature -8 / Freezing level dropping gradually to 1000 m.
SUNDAY: Cloudy and wet flurries, up to 5 cm / Moderate to strong, southwest ridgetop wind / alpine high temperature +1 / Freezing level 1500 m.
MONDAY: Wet snow, 10-20 cm. / Strong, southwest ridgetop wind / alpine high temperature 0 / Freezing level rising to 2000 m.
TUESDAY: Snow and rain, 10-20 cm. / Moderate, gusty southwest ridgetop wind / alpine high temperature +1 / Freezing level 2000 m.
No new avalanche observations submitted on Thursday or Friday.
On Wednesday, the northern part of the region, several natural avalanches were reported up to size 2 with some older ones from the previous storm up to size 2.5. A couple of isolated natural glide crack avalanches up to size 1.5 were also reported. In the southern half, numerous natural wet loose avalanches occurred up to size 2 mostly from southerly aspects.
Last Tuesday, a large size 3 natural avalanche was observed on a NE aspect at 2400 m. It was reported as a cornice failure triggering the slope below and appeared to have slid on the early November crust near the base of the snowpack.
Have you been out and about in the mountains? If so please submit to the Mountain Information Network (MIN). It doesn't have to be technical it can be as simple as a photo. Photos are especially helpful! Sending out a big thank you to the already submitted MIN's this season. Thanks everyone!
Recent sun and warm air well into the alpine had the greatest impact on the upper snowpack, melt freeze conditions exist on most aspects and elevations. Where dry snow prevails, such as shaded alpine and upper treeline slopes, wind slabs have developed on leeward terrain.
Large surface hoar growth has been reported slopes sheltered from the warm temperatures, sunshine and wind.
The lower snowpack is characterized by a few crusts that formed during warm periods over the last month.
