Regions
Vancouver Island.
Confidence
High - Weather models in agreement and good data for east and north. (limited obs for the west/Strathcona).
Travel & Terrain Advice
Avoid exposure to wind loaded slopes in the alpine and treeline on NE-NW aspects. Wind slabs will have a poor bond to the near surface crust. As the rain begins to fall avoid exposure to terrain traps such as cliffs, tree bands and depressions like streams. Also avoid travel in gullies that will funnel the potential wet slides. The crust from Sunday’s rain event has variable support to both skis and foot traffic and is very difficult to travel on. Frozen debris from wet slides and tree bombs also presents a navigation challenge. Move slow and carefully as these hazards now lurk under newly fallen fresh snow.
Avalanche Summary
No new avalanche activity reported during the past two days. Clear skies have allowed observations of the widespread wet loose and wet slab activity during Sunday’s rain event. As expected there are numerous paths that ran up to size 1 and a few up to size 2.
Snowpack Summary
A dusting of new snow over a nasty crust. A few isolated wind slabs near ridge line and on cross loaded features.
Snowpack Details
Surface: Variable support rain crust, buried under light amounts of new snow. Upper: Moist snow from Sunday's rain event. Mid: Preserved dry snow with a few smooth failures in tests. Lower: Well settled.
Past Weather
Cold temps have created a widespread rain crust that is now buried under light to moderate amounts of new snow. Moderate SW winds have created isolated wind slabs that have a poor bond to the crust below.
Weather Forecast
Moderate new snow giving way to our next rain event. Wednesday: 5-10 cm of new snow, temps -3 to -6, winds light to moderate SW-SE, freezing level 0-800 m. Thursday: 5-10 cm of new snow leading to 2-5 mm of rain, temps -5 rising to +3, winds light SW rising to moderate SE, freezing level 700 rising to 1150-1900 m. Friday: 2-10 mm of rain, temps +3 dropping to 0, winds light to strong from the SW, freezing level 2600 dropping to 1500 m.
Problems
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.
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.
Wet Slabs
Wet Slab avalanches are the release of a cohesive layer of snow (a slab) that is generally moist or wet when the flow of liquid water weakens the bond between the slab and the surface below (snow or ground). They often occur during prolonged warming events and/or rain-on-snow events. Wet Slabs can be very unpredictable and destructive.