Regions
Northwest Inland.
Confidence
Fair - Timing, track, or intensity of incoming weather system is uncertain
Weather Forecast
The next storm system is expected to reach the north coast on Saturday morning. Light precipitation and strong winds are expected for the inland region on Saturday and Sunday. Conditions should be milder to the north of the region. A weak ridge of high pressure should build on Monday.Saturday: Precipitation 5-10mm, freezing levels am: 600m pm: 1200m, ridgetop wind 40-60 km/h S-SWSat. Night/Sunday: Precipitation 5-15mm, freezing levels am: 1200m pm: 1000m, ridgetop wind 40-60 km/h S-SW Monday: Dry or light flurries, freezing levels am: 300m pm: 600m, ridgetop wind light SW-W
Avalanche Summary
A natural cycle was reported to have occurred on Wednesday. Activity tapered off on Thursday. The focus of the activity seems to be primarily wind slabs or storm slabs sitting over the early-March weak layer. Some of these smaller avalanches have stepped down to the deeper February weak layer creating larger, more destructive avalanches.
Snowpack Summary
Conditions are reported to be highly variable. Roughly 30-60 cm of snow now sits on a weak layer consisting of surface hoar and/or a thick layer of faceted snow on shady slopes at all elevations, a sun crust on steep solar aspects, and various wind affected surfaces in exposed terrain. Strong southwest winds have created dense wind slabs on exposed lee slopes and in cross-loaded features. In wind exposed areas, the snow surface is reported to be wind scoured or a very supportive wind-pressed slab. Moist/wet snow or melt-freeze crusts in the upper snowpack are likely at lower elevations, below roughly 1200m. The early February weak layer of facets, crusts, and/or surface hoar is buried down about 60-100 cm. Test results and isolated avalanche activity suggest this layer is still reactive to human-triggering. Basal facets and depth hoar remain a concern in areas with thin or variable snow cover.
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.