Avalanche Forecast

Sunday night: Cloudy with isolated flurries / light southeast winds / alpine low temperature -16

Monday: Cloudy / light southeast winds / alpine high temperature -10

Tuesday: Mostly cloudy / light southeast winds / alpine high temperature -11

Wednesday: Cloudy with sunny breaks / light variable winds / alpine high temperature -12

On Saturday, a skier triggered a size 2 wind slab avalanche of a layer of surface hoar; the crown averaged 25 cm. The avalanche was triggered just below an open and corniced ridge feature at tree line, and occurred in the southern end of the forecast region in the Selkirks. As you step out into steeper terrain, a slope-specific assessment is recommended.

Over the past few days avalanche observations have been limited to a handful of small (size 1) wind slabs, a few cornice failures, and loose dry sluffing in steep and southerly terrain.

With the strong winds last Tuesday, operators in the region reported small to large (size 1-2) wind slabs releasing naturally as well as several size 1-2 explosive-triggered cornices. 

Last Monday and Tuesday, several operators in the region reported small (size 1-1.5) human-triggered avalanches releasing on a weak layer of surface hoar on north, east and southeast aspects at treeline and below treeline elevations. These avalanches were breaking 25-45 cm deep. 

Previous winds scoured snow surfaces, loaded cornices, and formed stiff wind slabs in the alpine and around treeline. A thin sun crust may be found on steep solar aspects. Clear skies and cold temperatures are encouraging surface hoar growth and surface faceting. Below 1700-1800 m, 20-30 cm of snow is settling above a decomposing melt freeze crust. 

Observers continue to find a preserved layer of surface hoar down 25-50 cm in sheltered, open slopes at and below treeline. Most recent reactivity has been reported in the Selkirks towards the south of the forecast region (see avalanche summary). On the other hand, snowpack tests on this layer are trending to hard and resistant shears, as such it continues to warrant slope-specific assessment.

Deeper in the snowpack, a couple of older persistent weak layers may still be identifiable from late and early December, consisting of surface hoar and a crust with faceted snow and buried anywhere from 100-200 cm deep. Prolonged periods of inactivity and unreactive snowpack test results suggest that these layers have trended towards dormancy. 

• Carefully evaluate steep lines for wind slabs.
• Large cornice falls are dangerous on their own.
• Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.