Avalanche Forecast
Issued: Dec 10th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
rgoddard,
Avalanche Canada
Snow continues to slowly accumulate adding to the storm slab.
An increase in temperature and wind will be added more load to our buried weak layer.
Assess conditions while you travel. Watch and feel for signs of instability such as whumpfing, cracking, and recent avalanches.
Summary
Confidence
Avalanche Summary
The storm slab that formed from Thursday night's storm was reactive to explosives and ski cutand produced several decent size two avalanches. Some natural avalanches were also produced from this storm slab. People reporting in the MIN described hollow sounds and shooting cracks from wind slabs as well.
Snowpack Summary
Around 20 cm of fresh snow has fallen since Thursday. This sits on a variety of surfaces. In some places, it sits on wind slabs that were created by southwesterly winds that we experienced earlier this past week.
The middle of the snowpack consists of weak sugary layers of facets and surface hoar. A widespread rain crust remains near the ground, at the treeline, and below the treeline.
At treeline, snowpack depths vary from 120 to 200 cm.
Weather Summary
Saturday Night
Cloudy, 10 cm accumulation, winds southwest 10 gusting to 30 km/h, temperature -7 C at 1500 m.
Sunday
Cloudy, 3 cm accumulation with possible snow showers, winds southeast 10 gusting to 25 km/h, temperature -3 C at 1500 m.
Monday
A mix of sun and cloud, 2 cm accumulation, winds northeast 20 to 30 km/h, temperature -5 C at 1500 m.
Tuesday
Mostly sunny, no accumulation, winds northeast 10 km/h, temperature -13 C at 1500 m.
More details can be found in the Mountain Weather Forecast.
Terrain and Travel Advice
- Continue to make conservative terrain choices while the storm snow settles and stabilizes.
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
- If triggered, storm slabs in-motion may step down to deeper layers and result in very large avalanches.
- Pay attention to the wind, once it starts to blow fresh sensitive wind slabs are likely to form.
Problems
Storm Slabs
New snow with little wind is accumulating on a variety of surfaces that include a layer of low-density lighter snow. Warmer temperatures are expected to consolidate this new snow into a slab.
Small avalanches in the upper snowpack could trigger deeper weak layers, creating a larger-than-expected avalanche.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Persistent Slabs
Buried layers of surface hoar and facets have been reactive to human triggers in recent days. Reactivity has been observed in sheltered areas at treeline, where the surface hoar may be preserved, and in wind-loaded areas at upper elevations, where a cohesive slab has been formed above.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 11th, 2022 4:00PM
