Uncertainty about deep persistent slabs warrants a conservative approach to terrain after the storm.
Summary
Confidence
Moderate - Due to the number of field observations
Weather Forecast
FRIDAY: Cloudy, light southwest winds, freezing level dropping with alpine temperatures around -5 C.SATURDAY: Cloudy with isolated flurries, moderate southeast winds, alpine temperatures around -8 C.SUNDAY: Cloudy with sunny periods, light southeast winds, alpine temperatures around -8 C.
Avalanche Summary
On Wednesday, several loose wet avalanches were reported from steep rocky terrain at lower elevations where rain fell on snow. Storm slabs sitting on a weak layer of surface hoar and/or a crust are likely easy to trigger at higher elevations. Full depth avalanches continue to be a concern due to the weak faceted snowpack below old hard wind slabs. This deep persistent weak layer may take prolonged warm weather with consistent snowfall to settle and bond.
Snowpack Summary
20-25 cm of new storm snow has been transported by southwest winds and now sits on a mix of old surfaces left behind after the recent cold and windy weather. Expect the new storm snow to bond poorly where it is sitting on a weak layer of buried surface hoar and/or a hard old wind polished surface. The freezing level recently reached 1000 m, and below this level the snowpack is likely moist and will eventually form a hard crust. Most areas continue to have a shallow and weak snowpack that is about 120-150 cm at treeline. In general, the snowpack above treeline has been heavily wind effected; this has resulted in hard wind slabs above weak faceted snow.
shorton,
Avalanche Canada
