Recent observations of persistent slab avalanches indicate buried weak layers are touchy, particularly in openings like cutblocks and gullies. Also use caution at higher elevations, where wind slabs exist on all aspects.
Summary
Confidence
High -
Weather Forecast
MONDAY NIGHT: Clear skies, light to moderate northwest wind, alpine temperature -16 C.TUESDAY: Increasing clouds over the day with light afternoon snowfall, trace accumulation, moderate west wind, alpine temperature -15 C.WEDNESDAY: Cloudy with light snowfall, accumulation 5 cm, light to moderate northeast wind, alpine temperature -12 C.THURSDAY: Early-morning snowfall and afternoon clearing, trace accumulation, light to moderate northeast wind, alpine temperature -16 C.
Avalanche Summary
On Monday, small (size 1 to 1.5) wind slab avalanches were triggered naturally and by skiers. They were generally found on westerly aspects in exposed alpine terrain and around 20 to 30 cm deep.On Saturday and Sunday, many persistent slab avalanches were observed. A skier triggered a large (size 2 to 2.5) avalanche within a slide path on a northeast aspect near Fernie. The avalanche was about 40 to 80 cm deep, on a northeast aspect, and at 1700 m. Although speculative, it is suspected that the avalanche may have released on one or both of the weak layers described in the Snowpack Summary. There was also widespread large (size 2) persistent slab avalanches observed
- check the report out here and another one here. The avalanches also released on the surface hoar described in the Snowpack Summary. The slabs were 40 to 100 cm deep and occurred between 1550 m and 1700 m on north aspects. There has been substantial further evidence of instability within the buried weak layers, for example in the MIN reports
here, here,
and here.
Snowpack Summary
Around 20 cm of snow recently fell in the region, which has been redistributed by wind, forming wind slabs in lee terrain features at higher elevations. The wind was first westerly and switched to northeast, so wind slabs may be found on all aspects. In sheltered areas between 1600 and 1800 m, this recent snow may overly a weak layer of surface hoar crystals.Two more weak layers may be found within the snowpack. Surface hoar that was buried early-February may be found about 30 to 50 cm deep in shaded and sheltered areas above 1600 m. The mid-January layer of surface hoar is buried around 80 to 100 cm and is most prominent between 1600 m and 1900 m.The remainder of the snowpack is well-settled. Thin snowpack areas, such as in the far east of the region, may have weak and sugary faceted grains near the base of the snowpack.
mconlan,
Avalanche Canada
