Continually assess the snowpack for signs of instability. Be especially suspicious of shallow or rocky ridges and start zones.
Gusty wind and additional flurries will perpetuate the avalanche problem. Watch for more reactive pockets in open or alpine terrain. A weak layer of surface hoar is reported 20-40 cm below recent snow, possibly allowing slabs to be larger than expected. A few other concerning layers are found in the snowpack, however, recent avalanches seem to be within the storm interface.
Weak, faceted grains make up the basal snowpack. Where supportive to riders, a melt-freeze crust may be providing a bridging effect, making it more difficult to trigger deeper layers. Be especially suspicious of shallow or cross-loaded areas with variable snow depths.
A widespread and reactive storm slab was reported around the region Friday. Skiers, vehicles, and explosives triggered slabs to size 2.5 with most crowns 30-50 cm deep, and many reported at treeline elevations 1700-2100 m (note poor visibility and no alpine observations).
Please continue to share any observations or photos on the Mountain Information Network.
Flurries through Sunday may accumulate up to 15 cm. Fresh snow will cover a crust or moist snow up to 1900 cm. At higher elevations, 20-40 cm of recent snow has buried a layer of surface hoar in wind-sheltered terrain, primarily around treeline.
A facet/crust layer is down 40-90 cm (and 2-10 cm thick at TL elevation), and the mid-pack below is settled and consolidated. A concerning and weak layer of crust and facets makes up the basal snowpack. Treeline snow depths average 150-210 cm.
Saturday night
Partly cloudy and isolated flurries. Light southeast ridgetop wind increasing into the morning. Treeline low temperature below -3 C. Freezing level falling below 1000 m.
Sunday
Flurries through the day, up to 15 mm in 24 hours, localized areas could accumulate 20 cm. Gusty south-southwest ridgetop wind. Treeline high temperature 0 C. Freezing falling to valley bottom.
MondayFlurries through the day, up to 5 cm. Decreasing south ridgetop wind. Treeline high temperature -2 C. Freezing level 1300 m.
TuesdayCloudy with isolated flurries. Light southwest ridgetop wind. Treeline high temperature -3 C, freezing level below 1000 m.
More details can be found in the Mountain Weather Forecast.
