Avalanche Forecast
Issued: Dec 28th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
jleblanc,
Avalanche Canada
There is a Special Public Avalanche Warning in effect for this region. Learn more: avalanche.ca/spaw
Slabs are now primed to release and smaller avalanches may trigger buried weak layers producing large avalanches. It's a good time to play it conservatively.
Summary
Confidence
Low
Avalanche Summary
After the storm, numerous natural avalanches were reported on planar and unsupported features. It is likely that avalanches occurred at higher elevations, as conditions were prone to a natural avalanche cycle. Where avalanches did occur naturally, slabs should be expected to be primed for triggering.
Please continue to share any observations or photos on the Mountain Information Network.
Snowpack Summary
Between 30 and 60 cm of moist dense storm snow is resting on low-density weak facets grains, which gives the snowpack an upside-down feeling. This recent snow may not bond well to previous surfaces that include small surface hoar crystals, sugary faceted grains, and hard wind-packed snow.
At upper elevations, recent wind slabs have developed from moderate to strong southerly winds. A very thin and breakable crust may be present at upper elevations due to warmer temperatures. At lower elevations, a rain crust can be found. A buried weak layer from November lies 60 to 110 cm below the surface. Smaller avalanches may step down to this deeper layer if heavier loads are introduced.
The snowpack is still fairly thin and faceted, with roughly 140 to 160 cm at treeline.
Weather Summary
Wednesday night, precipitation will weaken behind the cold front. A cooler and drier air mass will affect the region for the following days.
Wednesday night
Mainly cloudy, isolated flurries, westerly ridge winds up to 50 km/h, treeline temperatures around -12 °C.
Thursday
A mix of sun and cloud, isolated flurries, southwesterly ridge winds up to 40 km/h, treeline temperatures around -9 °C.
Friday
Cloudy with sunny periods, light snow up to 2 cm, southwesterly ridge winds at 30 km/h, treeline temperatures -8 °C.
Saturday
Cloudy, light snow up to 2 cm, southwesterly ridge winds increasing to 45 km/, treeline temperatures around -6 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Carefully monitor the bond between the new snow and old surface.
- Storm slabs in motion may step down to deeply buried weak layers resulting in very large avalanches.
- Avoid rock outcroppings, convexities, and anywhere the snowpack is thin and/or variable.
Problems
Storm Slabs
Moist storm snow is overlying a widespread persistent weak layer. Reactivity of these slabs may persist longer than expected, with the cooling trend expected.
Riders can easily trigger avalanches in areas where the snowpack varies from thick to thin. Watch for larger-than-expected avalanches due to the presence of a buried weak layer.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 29th, 2022 4:00PM
