Summary
Confidence
Fair - Timing or intensity of solar radiation is uncertain on Saturday
Weather Forecast
Unsettled conditions are expected for Saturday and Sunday. Light winds and convective snow showers are forecast to bring up to 10 cm on Saturday. Clearing overnight should turn to broken skies during the day on Sunday. A ridge of high pressure is expected to bring mostly clear skies on Monday. The freezing level is forecast to be about 1200 metres on Saturday and Sunday, and then lower to about 800 metres on Monday.
Avalanche Summary
Another natural size 4.0 avalanche was reported from the region that may have released on a weak layer of basal facets, or scoured down to the ground once it was in motion. There were also natural size 3.0 avalanches on various aspects in the alpine. Skier controlled avalanches up to size 2.5 were reported, and a couple of skier accidental size 1.0 were also reported.
Snowpack Summary
Moderate precipitation ended around midnight after bringing 15-20 mm of water equivalent. The freezing level went up to about 1400 metres during the storm, so snowfall amounts vary by elevation. The recent series of storms have developed a storm slab that is about 100 cm thick. The storm slab is sitting on a mix of old hard windslabs and crusts. There is a persistent weak layer (PWL) of buried surface hoar from mid-february that is buried between 100-200 cm that is the main concern. This PWL shears with a fracture character that promotes wide propagations that result in very large avalanches. Recent avalanches up to size 4.5 have exceeded historical avalanche paths and resulted in the demolition of old timber.
triley,
Avalanche Canada
