A week of heavy snowfall and strong winds have left large storm slabs and cornices primed for human triggering. Avoid overhead hazards and stick to mellow terrain.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
We're looking at scattered flurries and cool temperatures throughout the forecast period. MONDAY: Cloudy with scattered flurries and 5-15 cm of new snow, light gusting strong south winds, alpine temperatures around -11 C. TUESDAY: Isolated flurries with up to 5cm of new snow, 20-40 km/h south winds, alpine temperatures around -10 C. WEDNESDAY: Light flurries with 5-10cm possible, 20-30 km/h south winds, alpine temperatures around -9 C.
Avalanche Summary
On Saturday, several size 2 natural storm slabs were reported in alpine terrain and explosive control and ski cutting produced size 1-1.5 avalanches at treeline and in the alpine. On Thursday, a size 2.5 deep persistent slab avalanche was reported from the Elkford-North riding area. It was from approximately 2500 m on a SE aspect. It looked to be 24 hrs old and likely failed earlier in the storm. It failed within the basal facets (deep persistent slab) and scrubbed down to rocks.Natural activity is expected to taper off, but storm slabs will remain primed for human triggering.
Snowpack Summary
Another 5-15 cm of new snow fell on Saturday-Sunday, bringing the total from the past week to 40-80 cm. Strong southwesterly winds redistributed the new snow onto leeward slopes, building thicker and stiffer slabs. The new snow will likely have a poor bond to the old snow interface that consists of stiff wind slabs, crusts, and facets. The mid-pack in this region is generally strong, but the bottom third of the snowpack is composed of weak facets (sugary snow crystals). Approximately 100-120 cm of settled snow sits above this weak layer of sugary, rotten facets that developed in December. This remains a concern and should be on your radar, especially with the recent loading from snow and wind.
mgrist,
Avalanche Canada
