Regions
Northwest Coastal.
Avalanche hazard will likely be on the rise as forecast storm snow begins to stack up.
Confidence
Fair - Intensity of incoming weather systems is uncertain on Friday
Weather Forecast
Expect 10-25 mm of precipitation overnight Thursday, with the heaviest amounts in southern coastal part of the region, and freezing levels dropping to 1200 m by Friday morning. Light snowfall is expected to continue for Friday with light to moderate westerly winds. Saturday morning is expected to be unsettled before another storm in the afternoon, with freezing levels remaining around 1200 m. Expect another 10-20 cm by Sunday morning falling under strong southwesterly winds, and an additional 5-10 cm on Sunday with freezing levels remaining around 1200 m. Again, the heaviest snow amounts are expected for the southern coastal parts of the region.
Avalanche Summary
No new avalanches were reported on Wednesday, but poor weather hampered observations. On Tuesday a skier triggered a small storm slab on a NE facing feature around 2000m in the southern portion of the region.
Snowpack Summary
30-50 cm thick fresh heavy storm and thicker wind slabs are poorly bonded to older stiff wind slabs, melt-freeze crusts, or other slippery previous snow surfaces. On sun-exposed slopes and at lower elevations, the snowpack is likely in a spring melt-freeze cycle. A hard crust with weak facets may be lurking as deep as a metre down. This condition seems more specific to the northern parts of the region. Although reports suggest this persistent weakness has gained significant strength, I'd be wary of the possibility of isolated large avalanches on steep, unsupported slopes, especially if temperatures increase, or if solar radiation is strong. The mid-pack is generally well-settled and strong. At the base of the snowpack, weak facets may be found, particularly on shallow alpine slopes in the north of the region. Cornices are large and potentially fragile.
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.