Avalanche Forecast
Issued: Dec 27th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs.
rgoddard,
Avalanche Canada
There is a Special Public Avalanche Warning in effect for this region. Learn more: avalanche.ca/spaw
Warming then cooling temperatures have affected the snowpack. New slabs may produce rider-triggered avalanches.
The top layer of snow is "upside down." If you start to see evidence of reactivity, consider the danger rating higher.
Assess conditions as you travel and avoid overhead hazards.
Summary
Confidence
Avalanche Summary
Few to no avalanche reports throughout our region. However, it is expected that Monday's warm temperatures and precipitation which fell as rain and freezing rain in many areas created the conditions for a cycle of natural avalanches. Where it was not slid naturally, slobs should be expected to be primed for triggering.
Please continue to share any observations or photos on the Mountain Information Network.
Snowpack Summary
Monday's warm temperatures have likely promoted slab development in the top layer of the snowpack. Precipitation that likely fell as rain could have created a crust with cooling temperatures that started Monday night. Previous to Monday, this past weekend's snowfall totaled between 35 and 55 cm. Wind slabs have developed in the alpine and at treeline from moderate to strong southeast and southwest winds.
New snow may not bond well to previous surfaces that include small surface hoar crystals, sugary faceted grains, and hard wind-packed snow. A buried weak layer from November lies 60 to 110 cm below the surface and avalanches may slide on this layer if heavier loads are introduced by smaller avalanches running on top of them or heavy wet snow or rain.
The snowpack is still fairly thin and faceted, with roughly 140 to 160 cm at treeline.
Weather Summary
Tuesday Night
Cloudy, up to 4 cm accumulation, 15 km/h west wind, treeline temperatures around -8 to -5 °C.
Wednesday
Cloudy with the chance of sun, trace accumulation, 15 to 20 km/h west wind, treeline temperatures -10 to -7 °C.
Thursday
A mix of sun and cloud, trace to 4 cm accumulation, 10 to 30 km/h southwest wind, treeline temperatures -8 to -12 °C.
Friday
Cloudy with sunny periods, 2 cm accumulation, 15 to 25 km/h southwest wind, treeline temperatures -8 °C.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
- Watch for changing conditions today, storm slabs may become increasingly reactive.
- Storm slabs in motion may step down to deeply buried weak layers resulting in very large avalanches.
- Be carefull around freshly wind loaded features.
Problems
Storm Slabs
Weekend snow that came in cold and light was affected by our recent warm up. This will promote the formation of slabs and will likely increase avalanche activity. A cooling trend is starting to solidify this layer. New snow may not bond well to previous surfaces and could be easily triggered by riders.
At higher elevations wind slabs are likely due to moderate to strong south southwest winds.
Possible buried weak layers could be triggered by avalanches in motion and result in large scale avalanches.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 28th, 2022 4:00PM
