Avalanche Forecast
Issued: Dec 15th, 2022 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Deep Persistent Slabs.
LP,
Avalanche Canada
Increasing winds through Friday will move loose surface snow around in alpine terrain. Although we don't expect a large loose dry cycle, this could be enough of a trigger for one of the deeper weak layers.
Summary
Confidence
Avalanche Summary
Over the past few days, both ski hills have triggered deep slabs up to size 2 with explosives or sometimes with a ski cut after the explosive failed to trigger the slope. Parks Forecasters have noted large whumphs in the Sunshine Backcountry on Tuesday and in the O'hara region on Wednesday. No new naturals have been observed for the past few days.
Snowpack Summary
20-60 cm of snow has formed a slab over a very weak base consisting of facets. Thin crusts can be found on the facet interface at lower elevations and on solar slopes. Snowpack depths at treeline range between 60 and 120 cm. Below treeline, small sluffs may be triggered in steep features where the ski and foot penetrations are to the ground in a very weak facetted snowpack,
Weather Summary
Friday: Alpine high -10, low -20. Winds moderate to strong NW. In the late afternoon and overnight, there may be localized heavy flurries with the descent of a strong cold front. On the Eastern slopes, we may see up to 10 cm, elsewhere, 2-5 centimetres.
Saturday: Alpine high -20, dropping to -25 throughout the day. Alpine winds will ease to light NE. 5 cm of snow.
Sunday: Alpine temperatures will continue to cool -25 to -35 range with light NE winds. Expect some clouds and light flurries on the East slopes.
Terrain and Travel Advice
- Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
- Uncertainty is best managed through conservative terrain choices at this time.
Problems
Deep Persistent Slabs
A 20-60 cm slab has formed over the very weak basal facets, with thin crusts at the interface at lower elevations and on some solar slopes. Human triggering is likely on any steep slopes where a cohesive slab of snow is found. This problem will remain for the foreseeable future. Below treeline, the snowpack is very weak and unsupportive.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 16th, 2022 4:00PM
