Regions
Vancouver Island.
Confidence
Moderate - moderate- uncertain of precipitation amounts
Travel & Terrain Advice
Minimize overhead exposure during periods of heavy loading from new snow and wind. Avoid freshly wind loaded features.
Avalanche Summary
No new natural avalanches reported, no explosive avalanche control conducted.New snow, moderate south and north wind all falling on hard and well developed crust. Expect to find wind slab avalanches on all aspects and in the alpine and tree line. Expect new snow to bond poorly to the old crust.
Snowpack Summary
During the overnight period, light new snowfall of up to 15 cm will bury a well developed melt freeze crust found on all aspects and elevations. Isolated areas protected from both the sun and wind below tree line had very small surface hoar and its likely this will be buried. Below this upper melt freeze crust well settled and dense snow continues to strengthen.
Snowpack Details
Surface: 10-15cm new snow. Upper: hard melt freeze crust. Mid: well settled. Lower: well settled
Past Weather
A period of cool and clear conditions with temperatures in the alpine falling to below -10. Winds from the north west persisted and built during daytime to moderate.
Weather Forecast
During the initial overnight period of this forecast, all mountainous terrain zones within the forecast area will receive up to 15 cm of new snow. Moderate south west winds will accompany the storm with temperatures remaining cool. In the storms wake, north west winds will ramp up to moderate, skies will clear and temperatures will warm with freezing levels rising to 1000 m.Another storm arrives Friday with continued cool temperatures and light to moderate snow fall.Wednesday: 5-15 cm of overnight snowfall becoming clear in the am temps -3 to -1, moderate Sw becoming Nw, freezing level 200 m rising to 900 m mid day.Thursday: 5 cm light snowfall temps -6 rising to 0, winds light Sw, freezing level 0 m rising to 1000 m mid day.Friday: 5- 10 cm of moderate snowfall , temps - 3 to 0 , winds light to moderate Sw, freezing level 600 m rising to 1400 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.
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.