A return to more winter-like conditions is expected for Friday and Saturday with 5 to 10cm of new snow forecasted for the region. The widespread natural avalanche activity we've been seeing this past week will likely subside with the drop in temperatures, but the possibility of a human triggering the deep persistent problems still exists.
Also keep an eye out for local wind or storm slab development as this next weather system moves through, since there is a high amount of uncertainty in the forecast.
There is a cornucopia of weak interfaces throughout the snowpack depending on aspect, elevation, and local terrain influences. There have been a few avalanches this past week which appeared to have stepped down to multiple layers.
The bottom of the snow pack is inherently weak with well developed Facets and Depth Hoar. Persistent slab avalanches have stepped down to the deep persistent slab since the last storm meaning large triggers can influence this basal weakness.
Several wet loose avalanches observed in the last week occurring mid to late afternoon at all elevations southerly aspects with many stepping down to the basal weakness or triggering persistent and deep persistent slab avalanches. Large to very large deep persistent slabs have been observed throughout the region, generally triggered by a small loose wet slide, or a cornice fall.
Don't forget to post avalanche observations to the MIN.
A crust has formed on solar aspects at all elevations, and on northerly aspects at low elevations. Approximately 20-30cm down is a buried sun crust at low elevations on steep southerly slopes and a surface facet layer in sheltered terrain. The mid-pack is 40 to 80cm of supportive facetted snow. Near the ground it is generally weak with large facets and depth hoar.
Friday
Flurries.
Accumulation: 7 cm.
Alpine temperature: High -5 °C.
Ridge wind northwest: 10-20 km/h.
Freezing level: 1500 metres.
Saturday
Cloudy with sunny periods and isolated flurries.
Precipitation: Trace.
Alpine temperature: Low -11 °C, High -5 °C.
Ridge wind light to 15 km/h.
Freezing level: 1600 metres.
Detailed weather forecasts from Avalanche Canada: https://avalanche.ca/weather/forecast
