Regions
Vancouver Island.
A few natural avalanches where reported from last week, Friday ski cutting on steep terrain produce size one loose dry avalanches to size one. Overall the snow-pack tightened with no reports or observations over the past weekend.
Past Weather
Cool temperatures and strong North wind prevailed over the past forecast period.
Weather Forecast
Clear conditions are expected to continue with a rapid rise in both temperatures and freezing level forecast.A strengthening high pressure system will push the storm track to the south of the forecast region.Monday: No new snow, Winds Light from the North, Freezing levels to 2500 meters.Tuesday: No new snow, Winds Moderate from the North, Freezing levels to 2200 meters.Wednesday: No new snow, Winds Light from the West, Freezing levels 800 meters.
Terrain Advice
Avoid avalanche terrain during periods of high hazard.Provide a wide berth to cornices and avoid travelling either above or below them. Choose low angle terrain and review route selection and objectives to ensure minimal exposure to overhead hazard.
Snowpack Summary
Clear and cool conditions have provided an ideal environment for surface hoar to grow and can be found at all elevations and aspects on terrain that is protected from the wind and sun. Strong north winds have continued to scour and redistribute any available snow to south aspects. Areas that have been undisturbed by the wind continue to provide excellent skiing and riding conditions. The mid and lower snow pack continues to gain strength and settle during the past period of cool and consistent temperatures. On solar aspects periods of clearing and warming unconsolidated the upper snow pack. Daily unconsolidated snow in the upper snow pack began to refreeze overnight forming a crust on steep solar aspects.
Snowpack Details
- Surface: A variety of surface conditions exist that include, Moist surfaces on solar aspects, surface hoar, wind scoured, and wind loaded in areas that are directly lee of winds.
- Upper: A supportive and strengthening bond between the past 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 - Forecast models all agree on warming temperatures and rising freezing levels.
Problems
Cornices
Cornice Fall is the release of an overhanging mass of snow that forms as the wind moves snow over a sharp terrain feature, such as a ridge, and deposits snow on the downwind (leeward) side. Cornices range in size from small wind drifts of soft snow to large overhangs of hard snow that are 30 feet (10 meters) or taller. They can break off the terrain suddenly and pull back onto the ridge top and catch people by surprise even on the flat ground above the slope. Even small cornices can have enough mass to be destructive and deadly. Cornice Fall can entrain loose surface snow or trigger slab avalanches.
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.