Use caution in wind effected terrain, wind slab over facets, surface hoar or a crust remains the primary concern.
Previous outflow wind has impacted open terrain on various aspects. This has formed wind slabs that are bonding poorly to underlying surface hoar and facets on the early February crust.
Over the past week we have seen a pattern of human and remotely triggered size 1 to 1.5 wind slab avalanches with a few being up to size 2. Human-triggered avalanches have occurred on a range of aspects. Slabs have been averaging 20 - 30 cm thick, with some failing on buried surface hoar and propagating widely.
Sun and wind have created variable surface conditions. All exposed terrain is highly wind effected. A crust exists on all aspects at lower elevation and up to mountain tops on south aspects. The snow surface will likely become moist throughout the day.
Roughly 30 cm of snow sits above large surface hoar and/or faceted crystals at treeline and above. This is most problematic in places where wind slabs have formed over it. A widespread, supportive crust exists 30 to 40 cm below the surface. It is an excellent bed surface for slabs run to on.
The snowpack is well bonded and strong below this crust.
Monday Night
Mostly cloudy with trace amounts of new snow possible. 10 to 20 km/h south alpine wind. Treeline temperature -2°C, potential temperature inversion with colder temps at valley bottom.
Tuesday
Mostly cloudy with up to 5 cm of new snow expected in the alpine. 15 to 30 km/h southwest alpine wind. Freezing level rising to 1700 m.
Wednesday
Mostly cloudy with up to 10 mm of mixed precipitation expected. 15 to 30 km/h southeast alpine wind. Freezing level around 1900 m.
Thursday
Mostly cloudy with up to 5 cm of new snow expected in the alpine. 5 to 15 km/h southeast alpine wind. Freezing level around 1600 m.
More details can be found in the Mountain Weather Forecast.
