Avalanche Forecast
Issued: Dec 23rd, 2018 4:07PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
kdevine,
Avalanche Canada
Persistent slabs are tricky to manage and generally require patience and conservative terrain choices. Check out the new Forecaster Blog for a great explanation on how to best manage a persistent slab problem. Click here to read the blog.
Summary
Confidence
Moderate - Due to the number of field observations.
Weather Forecast
SUNDAY NIGHT - Cloudy with clear periods and isolated flurries / southwest to west winds, 20-40 km/h / alpine low temperature near -8°c. MONDAY - Cloudy with sunny periods / light west winds / alpine high temperature near -8°c. TUESDAY - A mix of sun and cloud / light southwest winds / alpine high temperature near -8°c, low temperature near -10°c. WEDNESDAY - Cloudy with sunny periods / light southwest winds / alpine high temperature near -10°c, low temperature near -12°c.
Avalanche Summary
Several explosives triggered avalanches to size 2.5 were reported in the region on Saturday. No new natural avalanches have been reported. One natural size 2 avalanche that was triggered by a cornice was reported in the region on Friday. One size 1.5 explosives triggered avalanche was reported on Thursday.
Snowpack Summary
60-90 cm of recent snow has formed a slab that sits on a persistent weak layer of facets (sugary snow) that formed during the dry weather in early December. Though avalanche activity on this layer has slowed down in recent days, it may still be easy for humans to trigger avalanches on this layer in certain terrain features. Steep features where the underlying ground cover is smooth, places where the snowpack depths are variable, and large convex features are some of the more likely places to trigger this layer. The lower snowpack has a weak structure composed primarily of facets. It is likely that an avalanche triggered on the persistent slab would step down to the lower facets, resulting in a full depth avalanche.
Problems
Persistent Slabs
60-90 cm of snow sits on a weak layer of facets (sugary snow). The snow below this layer consists primarily of facets all the way to the ground. Avalanches triggered on this layer will likely step down to the ground, resulting in large avalanches.
Be suspect of thin snowpack areas, where it may be easier to trigger the persistent slab.Use conservative route selection, choose moderate angled and supported terrain with low consequence.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 24th, 2018 2:00PM
