Avalanche Forecast
Issued: Dec 14th, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Persistent Slabs.
kdevine,
Avalanche Canada
An unusually shallow snowpack exists in the region right now. A persistent slab problem has been responsible for many recent avalanches, and test results suggest that this layer could propagate widely, resulting in large avalanches. Conservative terrain selection is advised.
Summary
Confidence
Moderate - Uncertainty is due to the fact that persistent slabs are particularly difficult to forecast.
Weather Forecast
SATURDAY NIGHT - Cloudy with clear periods / light northwest winds / alpine low temperature near -9
SUNDAY - Cloudy with sunny periods / northwest wind 15-30 km/h / alpine high temperature near -8
MONDAY - Cloudy with scattered flurries, up to 5 cm / southwest wind, 20-40 km/h / alpine high temperature near -5
TUESDAY - Flurries, 10 cm / southwest winds, 40-70 km/h / alpine high temperature near -2
Avalanche Summary
There were no new avalanches reported on Saturday, however the presence of a persistent slab calls for caution. Persistent slab avalanches can be tricky to predict.
On Friday, there were several reports of natural, human and explosives triggered avalanches up to size 2. The majority of these avalanches released on a persistent weak layer that was buried in mid November.
On Thursday, there were several reports of human and explosives triggered avalanches up to size 2. Some of these avalanches stepped down to a weak crust/facet layer that was buried in mid November.
No new avalanches were reported on Wednesday.
Snowpack Summary
15-25 cm of recent fresh snow likely sits on a weak layer of surface hoar in some areas, as well as sugary faceted snow.Â
There is a persistent weak layer from mid November that consists of a crust/facet combination, that is now down approximately 35-70 cm. This layer has been responsible for several recent avalanches. Snowpack tests consistently indicate that this layer can be triggered by humans and propagate widely, resulting in large avalanches.Â
The snowpack is unusually shallow and weak for the Sea to Sky region. Snowpack depths range between 80-200 cm and taper quickly at lower elevations.
Problems
Persistent Slabs
A persistent weak layer has been responsible for numerous recent avalanches. This scenario is atypical for the sea to sky region, and needs to be treated with caution. The most recent storm is now several days behind us, but the likelihood of human triggered avalanches remains elevated.
Aspects: All aspects.
Elevations: Alpine, Treeline.
Likelihood
Expected Size
Valid until: Dec 15th, 2019 5:00PM
