While refrozen surfaces at lower elevations pose little avalanche hazard, large avalanches may be triggered in areas with wind-drifted snow at higher elevations. Be prepared to assess conditions and adjust your travel as you gain elevation.
Extreme winds from the southwest have drifted the storm snow into stiff slabs in wind-exposed areas that may be prone to human-triggering. This wind slab problem overlaps with areas where cornices have been rapidly loaded and could also act as triggers.
Saturday night: Cloudy, 5-10 cm of snow, moderate west winds, alpine temperatures dropping to -12 C.
Sunday: Increasing cloud, isolated convective flurries with trace accumulations, light southwest winds, alpine high temperatures around -8 C.
Monday: Mix of sun and cloud, isolated flurries with a trace of new snow, light west winds, alpine high temperatures around -10 C.
Tuesday: Increasing cloud, isolated flurries with trace accumulations, light southwest winds, alpine high temperature -10 C.
During the storm, numerous large (size 2-2.5) storm slab avalanches were reported in the region. They released naturally as well as from human and explosive triggers. These avalanches occurred on all aspects, mainly at treeline and alpine elevations. Reports indicate that cornices may be reaching their breaking point and may act as triggers for these avalanches. Below tree line, small wet loose avalanches were releasing naturally on Saturday.
There were two notable natural avalanches reported in the Selkirks on Thursday. These were very large (size 3.5-4) persistent slab avalanches breaking 100-250 cm deep on both southeast and northwest slopes above 2400 m. These avalanches add to the previous two observations of very large persistent slab avalanches over the past week. Although the likelihood is decreasing in the aftermath of the storm, easier-to-trigger storm slab avalanches or cornice fall may have the potential to step-down to this layer in isolated areas.
30-60 cm of storm snow has accumulated at upper elevations (generally above 1900 m). Higher snow totals fell in the northeastern parts of the region. Extreme southwest winds have drifted the snow into deeper, stiffer slabs in wind-exposed areas and have rapidly loaded cornices. During a warming event Saturday night, rain saturated snow surfaces up to around 1900 m that have since refrozen with cooling temperatures.
The mid and lower snowpack is generally well settled and strong. In the north of the region, a weak layer of surface hoar buried 90 to 170 cm deep may persist in isolated areas.
