As strong southerly winds redistribute storm snow, a more cohesive slab will build and reactivity in the weak layer will increase.
Watch for signs of instability such as whumpfing, cracking, and recent avalanches.
15 - 30 cm of snow now sits atop a preserved layer of surface hoar/facets. As wind redistributes snow into deeper pockets it will form a cohesive slab and be reactive to human triggering.
Several size 1 natural storm slab avalanches were reported Thursday insteep treeline and alpine lees.
Backcountry users should expect to see evidence of a natural avalanche cycle from strong winds within the storm at higher elevations. If you head out in the backcountry please support your community by submitting a MIN report!
15 - 20 cm of storm snow has buried a layer of surface hoar, size 5-10 mm, and facets. Surface hoar overlies wind-hammered surfaces including scoured easterly slopes and hard slabs on west and south slopes.
A layer that formed in mid-November can be found down 70 to 100 cm deep at treeline and above. This layer consists of a crust below 1200 m and a layer of surface hoar above this elevation. This layer has not shown recent signs of instability.
The depth of the snowpack at treeline varies widely from 100 to 200 cm and tapers rapidly below treeline. Many early-season hazards such as rocks, stumps, and open creeks exist below treeline.
Thursday Night
Cloudy with scattered flurries, 5 - 10 cm accumulation. Ridge winds southwesterly 30 to 50 km/h. Temperatures are -9 at 1500 m. Freezing levels 300m.
Friday
Mainly cloudy with scattered flurries, 2-5 cm accumulation. Ridgetop winds will be southerly 30 - 50 km/h. Temperatures are -6 at 1500 m. Freezing levels valley bottom.
Saturday
Mix of sun and cloud with isolated flurries, trace accumulation. Strong outflow winds in valleys. Ridge winds easterly 20 - 40 km/h. Temperatures are -9 at 1500 m. Freezing levels valley bottom.
Sunday
Mix of sun and cloud with isolated flurries, trace accumulation. Strong outflow winds in valleys. Ridge winds easterly 20 to 30 km/h. Temperatures are -11 at 1500 m. Freezing levels valley bottom.
More details can be found in the Mountain Weather Forecast.
