Now that the storm is over, signs of avalanche danger may be less obvious. Touchy wind slabs are lingering. If it’s sunny, avoid large sun-baked slopes.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain on Thursday
Weather Forecast
A brief clearing is expected to continue on Tuesday morning, before a Pacific frontal system pushes ashore late that day. Generally light precipitation is expected on Wednesday and Thursday, with the freezing level around 1800 m and winds light to moderate from the S/SW.
Avalanche Summary
Touchy wind slabs have formed on lee and cross-loaded slopes following southerly winds. These can be triggered by the weight of a person, even from a distance.
Snowpack Summary
Wind slabs (lee to recent S-SW winds) and wind-affected surfaces are the main theme at the snow surface. Around the Coquihalla, up to 20 cm new snow may have created a localised storm slab problem. Cornices may also be fragile. Older, buried wind slabs may be hard to spot. A crust/facet combo produces moderate, sudden results in snowpack tests. This layer is buried anywhere from 10 to 60 cm down. Below this crust, the snowpack is reported to be generally well-settled and strong. Below treeline, the diminishing snowpack is trending isothermal (same temperature throughout).
Problems
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind slabs that form over a persistent weak layer (surface hoar, depth hoar, or near-surface facets) may be termed Persistent Slabs or may develop into Persistent Slabs.