Reactive wind slabs will likely form throughout Sunday. Diligently watch for changing conditions and increased hazard as the day progress.
Strong winds and expected snowfalls (up to 15 cm) will likely reload previously scoured slopes and build fresh and reactive wind slabs on any exposed terrain, lee features, and around ridgelines. Uncertainty remains in how well the developing slabs will bond to hard and smooth surfaces.
A shift in the weather pattern is expected from Saturday on. Periods of snow, rising temperatures, and back-to-normal winds are expected up to Tuesday.
Saturday night: Cloudy with flurries up to 5 cm. Freezing level returning to valley bottom. Alpine temperatures around -6 C. Moderate southwesterly winds gusting to 50 km/h.
Sunday: Snow 5-10 cm. Freezing level rising to 1200 m. Alpine temperatures around -4 C. Strong southerly winds up to 50 km/h.
Monday: Flurries. Freezing level rising to 1400 m. Alpine temperatures around -2 C. Moderate southerly winds.
Tuesday: Snow 5-15 cm. Freezing level rising to 1600 m. Alpine temperatures around -1 C. Moderate southwesterly winds gusting to 50 km/h.
No new natural avalanches were reported in the last 24 hours. Snowmobilers were able to trigger a few small wind slabs (size 1) on convex alpine lee features around Hasler. Blowing snow was observed in open trees near Red deer burn.
Old and stiffer wind slabs have shown signs of instability on isolated features as human-triggered around Mt West on Thursday. Check out our field team's MIN report for photos and details.
Last week's extensive northerly winds have created heavily wind-affected surfaces in exposed areas and wind slabs in lee areas. Continued cold temperatures have transformed surface conditions since the latest snow (20-100 cm), about a week ago. A thin sun crust was observed on steep south-facing slopes at lower elevations. Under this recent snow, a widespread crust (1 to 20 cm thick) is present on all aspects and elevations.
Below the crust, 10-40 cm of more settled snow exists above the late January weak layer. This layer consists of weak faceted snow, a melt-freeze crust, and surface hoar crystals in isolated sheltered areas at treeline and below. In most areas, this layer is bridged by the thick crust above it. The base of the snowpack is expected to be weak and faceted in shallow, rocky slopes east of the divide.
