Regions
Vancouver Island.
Monday February 24th: 1 Skier triggered avalanche was initiated on Buck's run on NE aspect on Mt Washington backcountry on unsupported leeward terrain feature (Soft Slab on rain Crust). The fracture height was approximately a 30-40 cm and 20-25 Meters wide (therefore a size 1 to 1.5 avalanche) Equipment was lost however no complete burial and no injury.
Sunday February 23rd: Mt Washington Avalanche control reported avalanche initiation of storm snow/wind loaded features (soft slab) on most recent upper rain crust layer
Past Weather
A low pressure system will deliver light and consistent precipitation to Vancouver Island over the next several days to the north east of the island has persisted but is forecast to come to an end late Friday. Saturday an expected incoming weather systems will begin to deliver snow and wind, with a subsequent stronger weather system arriving Sunday.Friday: Trace amounts of snow late in the day, Winds Moderate from the South West, Freezing levels to 1000 meters.Saturday: 5 to 10 cm of snow, Winds Strong from the South West, Freezing levels to 1000 meters.Sunday: 15 to 25 cm of snow, Winds Strong from the South West, Freezing levels 1000 meters.
Weather Forecast
A low pressure system will deliver light and consistent precipitation to Vancouver Island over the next several daysTuesday: 2 to 10 cm of snow, Winds Moderate to Strong and reducing to Moderate winds again in afternoon from the South West, Freezing levels to 1000 meters.Wednesday: 4 to 14 cm of snow, Winds Moderate from the South West, Freezing levels to 1000 meters.Thursday: 3 to 7 cm of snow (possibility of 6mm of rain at Treeline and Below Treeline elevation, Winds Moderate from the South West, Freezing levels 1400 meters.
Terrain Advice
Careful route find and snow-pack evaluation are paramount during periods of sustained moderate snowfall and strong winds.Avoid traveling both above and below cornice features.Careful and cautious route finding when entering into or over convex rolls or steep features.
Snowpack Summary
The upper snowpack contains a melt freeze crust found down anywhere from 20-40cm from the snowpack surface. This melt freeze crusts has been responsible for a number of skier triggered avalanches in the past 48hrs. Expect this layer/interface to continue to cause avalanches in the size 1-2 category which are large enough to fully bury a skier or sledder. The incoming precipitation these next 72 hours, coupled with strong winds should continue to exarcerbate this upper snowpack issue, particularly in leeward or down wind areas where snow loading will occur.
Snowpack Details
- Surface: Light low density snow
- Upper: A supportive and reactive melt freeze crust down from 15 to 30 cm
- Mid: A variety of old crusts can be found.
- Lower: well settled and dense
Confidence
High - Weather models in agreement, Moderate field data available, insufficient Weather station data.
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
Wind Slabs
Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.
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.