Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches possible, human triggered probable.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Cariboos.
Tricky conditions with a slowly increasing load over multiple weak layers in the snowpack. Take a conservative approach to your terrain choices.
Confidence
Moderate - Due to the number of field observations
Weather Forecast
Saturday: Light snow. Light to moderate south-easterly winds. Alpine temperature near -10. Sunday: 5-10 cm snow. Moderate south-westerly winds. Alpine temperature near -7.Monday: 5-10 cm snow. Moderate south-westerly winds. Alpine temperature near -4.More information can be found in the Mountain Weather Forecast.
Avalanche Summary
Avalanche activity slowed on Thursday and Friday, but a few size 2.5-3 naturally and explosive-triggered slabs have been reported. These were around 120 cm deep and are suspected to have failed on the early January persistent weak layer. On Monday, there was evidence of a widespread natural avalanche cycle with very large avalanches being released (up to size 3.5). This occurred on all aspects, at all elevations, with depths of 40 to 100 cm, and generally occurring on the mid-January weak layer but sometimes on the mid-December layer. Also, a large (size 2.5) persistent slab avalanche was triggered by a skier at treeline, which stepped down to the mid-December weak layer. The slab was 65 cm deep and slid on a 30 to 35 degree north-facing slope.Although natural avalanche activity has diminished, there's still a good chance of triggering a surprisingly large avalanche with the weight of a person.
Snowpack Summary
The current snowpack is complex, with three active weak layers that professionals are monitoring. Recent storm snow has been shifted by winds to form wind slabs and cornices.Down about 30-70 cm is a crust and/or surface hoar layer buried mid-January. The crust is reportedly widespread, with the possible exception of high elevation north aspects. The surface hoar is up to 10 mm is size and has been reported at all elevation bands.Deeper in the snowpack, the early-January persistent weak layer is found 40 to 120 cm below the surface. It is composed of surface hoar on sheltered slopes and sun crust on steep solar aspects and found at all elevation bands. Snowpack tests show sudden fracture characters with easy to moderate loads and high propagation potential, as well as whumpfs and cracking with skier traffic. Another weak layer buried mid-December consisting of a facet/surface hoar/crust combination is buried 40 to 100 cm deep. It is most problematic at and below tree line.A rain crust buried in November is 100 to 150 cm deep and is likely dormant for the time being.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.