Lingering wind slab problems are keeping avalanche danger in a holding pattern for one more day. Strong sunshine and warming are set to undermine stability later in the week.
Weather Forecast
Tuesday: Mainly cloudy with isolated flurries and a trace of new snow. Light west winds. Alpine temperatures of -6.Wednesday: A mix of sun and cloud. LIght west winds. Alpine temperatures around -4 and rising in late afternoon and evening as a strong temperature inversion establishes itself.Thursday: Mainly sunny with possible thin valley cloud. Light west winds. Strong alpine temperature inversion bringing alpine temperatures to around +5. Slightly cooler at lower elevations.
Avalanche Summary
Reports from Monday showed a couple of wind slabs releasing naturally and with ski cutting to Size 1.5 in the Fernie area. On Sunday, avalanche control with explosives triggered numerous size 1 dry loose avalanches above 1900 m from northeast aspects. Reactive wind slabs and dry loose avalanches may persist through Tuesday. Please submit your observations this weekend to the Mountain Information Network. Give info, get info.
Snowpack Summary
Up to 50 cm of accumulated storm snow has fallen on the crust that formed a week ago. The buried crust is supportive and approximately 10 cm thick. It extends from 1600 m to mountain top elevations on all aspects. Lots of uncertainty exists with the new snow sticking to the crust. Winds are likely redistributing the new snow above treeline and possibly forming wind slabs on leeward slopes and terrain features. The average snowpack depth at treeline is 60-80 cm while a deeper snowpack exists in the alpine.
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.