A Special Public Avalanche Warning is in effect for this region. Widespread, large avalanche activity is possible on touchy buried weak layers. Don’t overthink it - maintain very conservative terrain choices and avoid overhead exposure.
Summary
Confidence
Moderate - Track of incoming weather systems is uncertain
Weather Forecast
FRIDAY: Partly cloudy, moderate to strong westerly winds, alpine temperature near -9 C, freezing level below valley bottom.SATURDAY: Partly cloudy, moderate to strong westerly winds, alpine temperature near -4 C, freezing level near 1000 m with possible inversion conditions.SUNDAY: Mostly clear with valley cloud, moderate westerly winds, alpine temperature near -2 C, freezing level near 1400 m with inversion conditions.
Avalanche Summary
The new 40 cm of storm has been reactive and produced small to large storm slabs or loose dry avalanches. One release stepped down to the early-season rain crust and facet layer. Storm slabs have most often been observed in direct lee features and steep slopes. Around 1900 m, ongoing reports of touchy conditions have been noted, such as whumpfing and cracking, which is indicative of touchy buried weak layers.
Snowpack Summary
An unstable weak layer from mid-December (predominantly feathery surface hoar crystals and/or a sun crust) is found at treeline and below treeline elevations. Slabs can fail easily on this layer, either naturally or with the weight of a person or machine. Forecasted new snow Thursday night will continue to stress this layer and likely make it easier to trigger.The snowpack is variable across the region, but persistent slabs are generally a widespread problem. Wind slab and storm slab distribution will be more variable. Hard wind slabs can be found in parts of the region due to recent extreme southwest winds but more recently northerly winds, which have reverse-loaded some slopes. This means that wind slabs may be found on every aspect. Windward alpine slopes may be scoured; and variable wind slabs are found at treeline and alpine elevations. New snow is likely to fail as storm slabs and/or loose avalanches. Deeper in the snowpack, an early-season rain crust and sugary facets exist. An avalanche in motion could step down to these deeper layers, creating a large and destructive avalanche. Overall snowpack depths are variable across the region. It is generally shallower in the east.
mconlan,
Avalanche Canada
