Summary
Confidence
Good - -1
Weather Forecast
Thursday: 5-10cm of snow with freezing levels in valley bottoms and light to moderate westerly winds. Friday: Generally dry with light westerly winds and freezing levels in valley bottoms. Saturday: light amounts of new snow possible with freezing levels in valley bottoms.
Avalanche Summary
A large widespread natural avalanche cycle is underway, but will probably taper off as the storm dissipates late Thursday, however fresh storm and wind slabs, as well as deeply buried persistent slabs will remain sensitive to human triggers. Three separate serious incidents occurred on Monday afternoon in the Duffey Lake and Southern Chilcotin areas, all of which had similar terrain characteristics with north through east facing steep treeline features. Two of the avalanches likely involved the mid-December persistent weakness, while the third was reported to have released on basal facets in a shallow snowpack area with a 50-75cm depth. All of the avalanches resulted in serious injury and at least two of them were human-triggered.
Snowpack Summary
As of Wednesday morning, over 30cm of new snow fell in the Duffy Lake area under strong southerly winds, with freezing levels generally below 1500m, but briefly peaking at 1800m. The Cascades were a dryer and warmer. Persistent weaknesses buried mid-December are primed for avalanches in the northern part of the region. Weak surface hoar is lurking generally down 60-90cm in sheltered treeline areas and below. In exposed treeline and alpine areas, weak facets with associated crusts are down generally 80-120cm, but wind-loading has resulted in highly variable slab thicknesses. Basal facets remain a concern in shallow rocky areas. Meanwhile in the Cascades, last weeks storm snow is generally well settled and right-side-up with mostly resistant shears on storm slab weaknesses in the top metre, but fresh wind slabs are touchy.
ccampbell,
Avalanche Canada
