Regions
Northwest Inland.
Confidence
Fair - Due to the number of field observations
Weather Forecast
Snowfall is expected to continue on Sunday before ending Sunday evening. A break between storms is expected for most of Monday before the next system arrives Monday night. Light snowfall is expected for Tuesday. The north of the region can expect less snowfall amounts than the south for the forecast period.Sat. Night/Sunday: Snowfall 5-15cm, freezing level am: 1200m pm: 1000m, ridgetop winds 30-50 km/h S-SW.Monday: A mix of sun and cloud, mostly dry during the day, freezing level am: 300m pm: 600-1000m, ridgetop winds 20-40 km/h W-NWMon. Night/Tuesday: Snow 5-15cm, freezing level am: 500m pm: 1200m, ridgetop winds 30-50 km/h SW
Avalanche Summary
We haven't received any reports from Saturday at the time of publishing but avalanche activity is expected to be occurring in the region. On Friday, a natural size 2 slab avalanche released on the early-March weak layer down 30-40cm on surprisingly low angle terrain (25-30 degrees).
Snowpack Summary
Conditions are reported to be highly variable. Roughly 30-60 cm of snow now sits on the early-March 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
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.
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.