The hazard may be higher than expected on solar aspects if the sun comes out and the temperature goes higher than forecast. Pay careful attention to cornice hazard.
Confidence
Fair - Timing or intensity of solar radiation is uncertain
Weather Forecast
Synopsis: Cool and unsettled conditions will prevail in the wake of a cold front that passed through the region last nightTonight: Cloudy, trace to 5 cm of precipitation, freezing level at valley bottom, winds light from the south west.Friday: Cloudy, trace of precipitation in the forecast, freezing level at valley bottom, light south ridge top winds.Saturday: Cloudy with snow, trace of precipitation, freezing level up to 1000 metres, ridge top winds, light to moderate from the south west.Sunday: Sunny with cloudy periods, No precipitation in the forecast, freezing level around 1300 metres, light ridge top winds from the south.
Avalanche Summary
No reports of avalanches from yesterday in the forecast region. Conditions seem to be improving, but both the Coquihalla and Joffre region area have recently experienced a large natural avalanche cycle. It may be too early to be stepping out to bigger objectives.
Snowpack Summary
Between 50 and 70 cm of recent storm snowstorm snow at upper elevations is sitting on a a variety of weak layers. Strong westerly winds continue to form wind slabs on lee slopes. The two persistent weak layers that remain a concern are:The March weak layer. A combination of hard wind-scoured slab surfaces in exposed terrain, facets and/or surface hoar in sheltered and north aspects, and sun crust on steep solar aspects and is generally widespread throughout the forecast region.A late January/early February crust/facet/surface hoar combo that is still showing up in snowpack tests with hard shear tests. This layer will be with us for a long time, and a slide triggered on this layer would be very large and destructive. Recent warming temperatures will be good for bonding within this layer, but a sudden increase in load, a cornice failure, or a big rain event could "wake up" this layer and result in large avalanches. There are also basal facets at the bottom of the snowpack from cold clear weather in early December, but for the most part these have not been a concern, however, recently, large avalanches have scoured some avalanche tracks down to the basal facets and even to the ground.
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.
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.