Tricky-Moderate: A weak layer of surface hoar continues to whumpf and crack. Choose conservative terrain and consider that hazard may be highest at treeline elevations.
Southerly winds have impacted snow at upper elevations, incoming northwest winds may reverse-load features. There's a lot of loose snow out there, expect fresh slabs to form where the wind picks up.
A layer of surface hoar and crust is found 50-90 cm deep in the snowpack. Limited slab properties have developed, yet recent whumpfing and cracking suggest this layer is primed for human triggers. Reports indicate this layer of surface hoar is most prevalent above 1700 m and disappears above 2200 m, however at upper elevations a crust may also provide a weak bond.
Keep an eye on the wind or rising temperatures, slabs may quickly form wherever the fresh snow is encouraged to bond; and with a weak layer of surface hoar below, slabs may be more widespread, extend into treeline elevations, and be more reactive than expected in sheltered areas.
On Wednesday, a natural avalanche cycle size 2-3 was reported in both the Selkirks and Monashees north of Revelstoke. Whumpfing and cracking were reported throughout the region.
On Thursday, skiers remote triggered a size 2 on surface hoar at treeline in the Selkirks south of Revelstoke. Throughout the region, widespread whumpfing and cracking continued to be reported.
A weak layer of surface hoar below recent snow has been responsible for recent instability. Reports suggest this interface is most prevalent at treeline, between 1700-2000 m.
20-30 cm recent snow remains low density in most areas with wind effect at upper-treeline and higher. Now buried 40-80 cm, a layer of surface hoar, crust, and faceted crystals is the primary concern of persistence and has been the key component of a past natural avalanche cycle. This layer has been most reactive between 1700-2200 m. Snowpack depths range from 70 cm at treeline to 150 cm in the alpine, with wind-loaded areas exceeding 200 cm.
Saturday night
Cold, valley cloud forming overnight. Light north wind up to 20 km/hr. Treeline temperature low -22 C.
Sunday
Cold, valley cloud burning off in the morning. North wind 5-15 km/hr. Treeline high temperature -12 C.
MondayIncreasing cloud and isolated flurries, trace accumulation. West wind 15-25 km/hr. Treeline high temperature -15 C.
TuesdayIncreasing wind and flurries, trace to 5 cm. Southwest wind 15-30 km/hr. Treeline temperature rising to -9 C.
More details can be found in the Mountain Weather Forecast.
