Fresh wind slabs may be reactive to human triggering at upper elevations, especially where they sit above a crust.
Fresh wind slabs may exist in leeward (N-NE-E) terrain features in the alpine and exposed treeline. These slabs will be most reactive where they overlie a slick crust.
Unsettled weather is forecast for the weekend. This will bring mostly cloudy skies, new snow 5-15 cm, and moderate to strong southwest winds at ridgetop. Freezing levels will rise to 1500 m during the day and drop overnight.
On Thursday, a few natural wind slabs up to size 2 were rep[otred from the alpine on northeasterly slopes. Skier triggered dry loose and small storm slabs were easily triggered within the new storm snow up to size 1.5.
On Wednesday, the recent storm snow was easily reactive to skier triggering, especially where it sits above a crust. Reports showed numerous dry loose and wind/storm slab avalanches size 1-2.
On Tuesday in the north of the region, several size 1-2 natural wind slabs were observed in the alpine. Throughout the region, a widespread wet loose/wet slab and deep persistent slab avalanche cycle occurred at all elevations up to size 3. The most reactivity was noted on solar aspects.
10-20 cm of new snow overlies up to 20 cm of denser snow above 2000 m and tapers rapidly at lower elevations. A melt-freeze crust exists on all aspects as high as 2000 m and to mountain top on solar aspects. Below the crust, the top 10-30 cm of the snowpack is moist. 50-60 cm of snow now sits over the mid-March interface at upper elevations.
Westerly winds have formed reactive wind slabs on leeward terrain in the alpine and exposed treeline terrain.
The early-December rain crust is approximately a metre off the ground. Reports have recently indicated that large slab avalanches have failed on this interface earlier this week following a rain and warming event. This layer may be dormant now due to colder weather, however, may appear again during the next big warm-up or increased load from wind, snow, and/or rain.
