Avalanche Forecast
Issued: Dec 21st, 2019 4:00PM
The alpine rating is , the treeline rating is , and the below treeline rating is Known problems include Storm Slabs and Persistent Slabs.
kdevine,
Avalanche Canada
The brunt of the storm may have passed, but human triggered avalanches remain likely. The region has recently received a huge dump of new snow that may take some time to stabilize. Choose conservative terrain and avoid overhead exposure to avalanche terrain.
Summary
Confidence
Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.
Weather Forecast
SATURDAY NIGHT - Mainly cloudy with scattered flurries / southwest wind, 20-30 km/h / alpine low temperature near -9
SUNDAY - Cloudy with sunny periods / southeast wind, 10-20 km/h / alpine high temperature near -8
MONDAY - Sunny with cloudy periods / southwest wind, 10-20 km/h / alpine high temperature near -8
TUESDAY - A mix of sun and cloud / southeast wind, 20-40 km/h / alpine high temperature near -10
Avalanche Summary
Observations on Saturday were limited due to ongoing storm conditions, but it is likely that a natural avalanche cycle was occurring throughout the day.Â
There were numerous reports of natural, human and explosives triggered avalanches up to size 3.5 on Friday.
There were numerous reports on Thursday of natural, explosives and human triggered avalanches up to size 3. Many of these were triggered remotely.
Snowpack Summary
The storm has finally abated in the North Columbias, which has received upwards of 80 cm since Thursday night. Storm slabs are widespread and are expected to remain reactive to human triggers on Sunday.
There is anywhere from 100-160 cm of snow on top of a widespread layer of large, feathery surface hoar crystals.
A weak layer that formed in late November is now over 170 cm deep. This is the layer of concern relating to the persistent slab avalanche problem. The weak layer may present as surface hoar, a crust, facets or a combination, depending on elevation and aspect.Â
Terrain and Travel
- Make conservative terrain choices and avoid overhead hazard.
- Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
Problems
Storm Slabs
Storm slabs are widespread and human triggering remains likely in most areas.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Persistent Slabs
A couple of weak layers formed in late November and early December are now over 100 cm below the surface. This layer may present as surface hoar, a crust, facets or a combination of those, depending on elevation and aspect.
Aspects: All aspects.
Elevations: All elevations.
Likelihood
Expected Size
Valid until: Dec 22nd, 2019 5:00PM
