7 AM update: Slabs may form with new snow, while previously formed wind slabs may persist in exposed terrain. Watch for wet avalanches at and below treeline due to rain.
As new snow accumulates, storm slab likelihood and size will increase. The added load may trigger slabs on the Christmas crust, especially on wind-loaded slopes at treeline and above.
Rain up to treeline has moistened the top of the snowpack. Watch for wet avalanches in steep terrain. Use particular caution above terrain traps.
On Saturday, explosives triggered a few slab avalanches up to size 2. Skiers were able to trigger size 1 slabs.
On Friday, small pocket wind slabs were reactive to skiers in immediate lee areas.
During recent explosive-control work, a few large (size 2 to 3) wind slab avalanches occurred in the Crowsnest area. While none of these avalanches propagated particularly wide, they all ran very far (full path) on old firm, buried crusts.
Fresh snow covers a variety of old surfaces, including surface hoar in wind-sheltered terrain and a sun crust on south-facing slopes. Below treeline, rain has moistened the snow surface.
20 to 40 cm of snow since Christmas continues to settle above a thin melt-freeze crust at elevations around 2000 m and below.
The mid and lower snowpack is characterized by multiple crusts, with moist snow persisting near the base in some areas.
Snow depths at treeline generally range from approximately 100 to 220 cm.
Saturday night
Cloudy. Up to 5 cm of snow. 50 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1700 m.
Sunday
Mostly cloudy. 10 to 20 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -2 °C. Freezing level 1800 m.
Monday
Mostly cloudy. 5 to 10 cm of snow. 40 km/h southwest ridgetop wind. Treeline temperature -6 °C. Freezing level 900 m.
Tuesday
Mostly cloudy. 5 to 10 cm of snow. 30 km/h southwest ridgetop wind. Treeline temperature -8 °C. Freezing level 300 m.
More details can be found in the Mountain Weather Forecast.
