Avalanche danger is high due to loading from new snow or rain, and wind.
Confidence
Fair - Intensity of incoming weather systems is uncertain
Weather Forecast
The Pineapple Express which has been bringing lots of moisture and warm temperatures over the Southern part of BC will continue to spread moderate to heavy precipitation until the end of the day Saturday, taper off on Sunday and pick up again on Monday as another storm passes through. Freezing levels are expected to hover between 1700m and 2000m and winds to blow moderate to strong from the southwest on Saturday. Freezing levels should to start lowering again by Sunday.
Avalanche Summary
Natural and skier triggered moist and wet slab avalanches up to size 2 were reported on Friday in the alpine and at treeline. These would have failed within the storm snow.
Snowpack Summary
The ~30 cm recent storm snow is now either wet under 1800m or moist above. Strong winds from the southwest have built thick, touchy wind slabs on east and northeast facing alpine slopes. The sustained rain forecast up to ~1900m through Saturday will continue to break down the late January crust, increasing the possibility of avalanches stepping down to deeper weak layers. Avalanche danger will therefore stay high and traveling in the backcountry will remain very dangerous. The mid-December crust/facet/surface hoar combo is found down 50-95 cm and could come out of its dormant stage making for some very large avalanches.
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.
Deep Persistent Slabs
Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.