Fresh wind slabs at higher elevations can be found on all aspects. Expect as temperatures warm, that human triggered avalanches will become likely.
Wind slabs may be more reactive where they sit on a weak layer of facets. Expect slab sensitivity to triggering and reactivity to increase as temperatures warm.
There is a weak layer of facets and depth hoar near the base of the snowpack in most alpine areas. The likelihood of triggering a deep persistent slab is low, however the consequence of doing so is high.
On Thursday explosive avalanche control missions triggered a very large avalanche size 3.5. This avalanche failed on the deep persistent slab layer and was 100 to 250 cm in slab depth, running over 500 meters in length. Earlier in the week natural and explosives triggered wind slab and loose dry avalanches were reported to size 1 and 1.5.
If you go out in the backcountry, please consider sharing your observations on the Mountain Information Network (MIN).
5-10 cm of low density new snow is sitting on weak faceted snow in many areas. In exposed terrain at treeline and above, this new snow is now obscuring old wind slabs.
The mid and lower snowpack is generally weak with several layers of note. Of greatest concern are weak facets and/or depth hoar located at the bottom of the snowpack, particularly in alpine terrain.
Snowpack depths at treeline range from 70 to 160 cm.
Friday Night
Mainly cloudy with isolated flurries, 1-2 cm of snow, southwest ridgetop wind 10 to 30 km/h, treeline temperature -14 °C.
Saturday
Mainly cloudy with isolated flurries, 1-2 cm of snow, west ridgetop wind 20 to 40 km/h, treeline temperature -15 °C.
SundayMainly cloudy with flurries, 2-4 cm of snow, southwest ridgetop wind 10 to 30 km/h, treeline temperature -10 °C.
MondayMainly cloudy with flurries, 2-4 cm of snow, southwest ridgetop wind 10 to 30 km/h, treeline temperature -8 °C.
More details can be found in the Mountain Weather Forecast.
