Watch for fresh, reactive wind slabs on north and east facing slopes in the alpine and treeline. Be especially cautious of wind slabs in steep, unsupported, and convex terrain features.
Southwesterly winds are building fresh wind slabs at higher elevations in lees. New wind slabs bury a variety of wind-affected surfaces including stiff wind slabs covering a thin temperature crust on southerly slopes from last week's northerly outflow winds. Avoid freshly loaded features, especially near ridge crests, roll-overs and in steep terrain.
On Sunday, a skier accidental wind slab avalanche was reported on a south-facing slope at 1800 m. This avalanche was 70 cm deep and is suspected to have slid on the Jan melt-freeze crust. Check out the MIN for a detailed report.
Thank you for the MIN's, please continue to post your reports and photos to the Mountain Information Network.
Southwest winds have redistributed 5-15 cm storm snow into fresh wind slabs over previously scoured surfaces on northern aspects. On southern aspects storm snow overlies stiff wind slabs. A breakable crust exists on the surface at lower elevations and on steep solar aspects to 1800 m. Softer snow still exists in sheltered areas at treeline and below.
A melt-freeze crust from mid-January is found down 30-40 cm in many areas but up to 70 cm in wind-loaded places. Isolated weak layers may exist within the middle and lower snowpack below this, but the thick crusts sitting above them make triggering avalanches on these layers unlikely.
Snowpack depths are 150 to 200 cm at treeline and taper rapidly below 1500 m.
Thursday night
Mainly clear with cloudy periods. Southwesterly ridgetop winds 40 to 60 km/h. Treeline temperatures -3 ˚C. Freezing levels 1200 m.
Friday
Mainly clear with cloudy periods. Southwesterly ridgetop winds 40 to 60 km/h. Treeline temperatures -1 ˚C. Freezing levels 1400 m.
Overnight cloudy with isolated flurries, 2-10 cm accumulation.
SaturdayMix of sun and cloud with isolated flurries, 2 cm accumulation. Southwesterly ridgetop winds 40 km/h. Treeline temperatures -1 ˚C. Freezing levels 1500 m.
SundayCloudy with scattered flurries, 2-5 cm accumulation. Southwesterly ridgetop winds 40 km/h. Treeline temperatures -1 ˚C. Freezing levels 1400 m.
More details can be found in the Mountain Weather Forecast.
