Regions
South Coast Inland.
Snowfall is forecast for the south of the region through the next few days, whereas the north will receive relatively little new snow. Danger ratings focus on the areas where accumulations will be greatest.
Confidence
Moderate - Forecast snowfall amounts are uncertain
Weather Forecast
WEDNESDAY: Cloudy with sunny periods in the north. Flurries in the south, accumulation 5-10cm / Light to moderate west wind / Alpine temperature -5 / Freezing level 1100 m. THURSDAY: Mostly cloudy with isolated flurries in the north. Snow in the south, accumulation 15-20cm / Moderate to strong west wind / Alpine temperature -3 / Freezing level 1300 m. FRIDAY: Mostly cloudy with isolated flurries in the north. Flurries in the south, accumulation 5-10cm / Light to moderate southwest wind / Alpine temperature -2 / Freezing level 1400 m.
Avalanche Summary
On Sunday there was a report of a skier triggered storm slab (size 1) on a westerly aspect in the high alpine, as well as sloughing in steep terrain. Saturday there was a report of a skier triggered size 1 storm slab on a north aspect at 1800 m, as well as a natural, size 2 on a west aspect at a similar elevation.Last week, on Thursday and Friday there were reports of isolated natural and skier triggered storm slab avalanches (size 1-1.5) from 15 to 30 cm deep on wind-affected convex and ridge top features in the alpine. All reports of recent avalanche activity have been from the northern part of the region. In the south only sloughing in steep terrain and thin wind slab activity in recent storm snow has been observed.
Snowpack Summary
Another 5-10 cm of snow Sunday night adds to last week's storm snow bringing totals to 20-40 cm of recent storm snow that sits on a crust that is present at all elevations on solar aspects as well as low elevation northerly aspects. On northerly and east aspects at treeline and alpine elevations the storm snow sits on a mix of large surface hoar and surface facets.Deeper in the snowpack in the north of the region, north and east aspects are harboring cold snow and a surface hoar layer buried early March that is about 30-50 cm below the surface. This layer exists at alpine and treeline elevations, but it is not everywhere. This layer has produced large human triggered avalanches in the north of the region in the past week. Also in the north of the region a weak layer buried mid-February is about 60 to 80 cm below the surface and has been reactive in snowpack tests. The layer is composed of sugary facets, a sun crust on solar aspects, and surface hoar that is present at and below treeline. In the south of the region, around the Coquihalla and in Manning Park, the recent storm snow overlies a recent crust that caps a well settled snowpack.
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.