Purcells

For more insight into the current tricky conditions, see the latest Forecasters Blog.

Expect fresh wind slab and loose dry snow avalanche activity to increase throughout the forecast period as snow flurries load exposed alpine and treeline feature. At treeline elevations and below, significant warming has made large persistent slab avalanches are highly sensitive to human triggers. In parts of the forecast area, very large destructive avalanches running to valley bottoms from major start zones remain a  concern. Neighboring forecast regions have recently reported large avalanches initiating in the new storm snow, then stepping down to deeper layers, some running full path to the ground. Cornice failures triggering large deep persistent avalanches have also been reported.

Fair - Intensity of incoming weather systems is uncertain

Saturday: Mainly cloudy with scattered flurries bringing 5-10 cm depending on drainage. Mostly light westerly winds with strong gusts associated with snow flurry activity. Freezing levels as high as 2000 m in the far south, but 1500 m in the north. Sunday: Cloudy with flurries bringing 10-20 cm depending on drainage. Generally moderate but gusty westerly winds. Freezing levels dropping slightly to 1800 m in the south and hovering at 1500 m in the north. Monday: A mix of sun and cloud with isolated flurries, but I would'nt be surprised if some drainages got another 10-20 cm. Generally light westerly winds gusting with flurry activity, and freezing levels down to 1400 m.

A 50-70 cm slab is bonding poorly to buried surface hoar and facets particularly on sheltered slopes such as cut blocks, and crust on previously sun-exposed slopes.  Warm temperatures and sun-exposure has been making these and deeper persistent slabs very sensitive to triggers at treeline elevations and below, and resulting in surface melt-freeze cycles as high as alpine elevations. The deeper facet/crust persistent weakness buried at the beginning of February, now down 60 to 160cm, has been described by avalanche professionals as "very weird". Although widespread, it has been highly variable in terms of reactivity. Convective flurry activity has already accumulated 10-15cm of fresh snow in some drainages, which has likely blown into touchy wind slabs on leeward slopes. Weak basal facets exist in many areas, but without a large load, triggering now is unlikely.