A week of snowfall and occasional strong winds has left wind slabs and some cornices primed for human triggering. Avoid overhead hazards and evaluate terrain carefully before committing to bigger lines.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
We're looking at occasional flurries and then a more organized system coming Thursday night. WEDNESDAY: Flurries overnight Tuesday with 5-15 cm of new snow, 20-30 km/h southwest winds, alpine temperatures around -7 C. THURSDAY: Cloudy with scattered flurries and up to 3-5 cm of new snow, 10-20 km/h southwest winds, alpine temperatures around -11 C. FRIDAY: Snow Thursday overnight into Friday (10-20cm) , 20-40 km/h southeast winds, alpine temperatures around -8 C.
Avalanche Summary
On Monday, explosive control and ski cutting produced size 1-1.5 avalanches at treeline and in the alpine. Cornice fall in Waterton Park resulted in a Size 2.5, entraining lots of snow. Natural activity is expected to taper off, but storm and wind slabs will remain susceptible to human triggering.
Snowpack Summary
We've had daily snowfalls of 5-10cm since Saturday, bringing the total from the past week to 50-80 cm. At times, 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
