Regions
Vancouver Island.
Confidence
Moderate - variability between forecast model precipitation amounts exist between western and eastern regions.
Travel & Terrain Advice
Minimize overhead exposure during periods of heavy loading from forecast new snow and moderate south wind. Avoid freshly wind loaded features. Identify and avoid all old avalanche debris and cornice debris. All hiding under a thin cover of new snow.
Avalanche Summary
Reports that new snow wind slab avalanches became touchy to skier triggering following the new snowfall Tuesday night. These small avalanches size 1 where located in isolated protected areas on north aspects and failed on the melt freeze crust.
Snowpack Summary
Past new snowfall has been highly wind effected and the prevalent surface condition is melt freeze crust, expect this hard crust to bond poorly with new snow forecast for the coming weekend. A few periods of cooling and clearing promoted surface hoar to form both at the surface of the melt freeze crust and within the new snow. Suspected that in isolated protected areas its been buried. Below the melt freeze crust well settled and well bonded snow can be found.
Snowpack Details
Surface: Variable surface conditions from pockets of new snow to very hard melt freeze crust. Upper: Dense and hard melt freeze crust. Mid: Well settled. Lower: Well settled.
Past Weather
A moderate storm has deliver in northern regions of the forecast area up-to 15 cm of new light snow. As the storm tracked south , precipitation amounts became less with the most southern portion of the forecast region receiving as little as 3 cm. The winds have been from both southerly and northerly direction with moderate wind transportation of snow. Temperatures have generally been cool in the alpine and at treeline.
Weather Forecast
Cool temperatures will continue as a new storm front Friday night will bring moderate south west wind and between 10 and 30 cm of new snow. Beginning Sunday, a ridge of high pressure will bring to the region, cool temperatures, light north wind and clear skies. Friday: 5-10 cm new snowfall temps -3 to 0, winds moderate Sw, freezing level 700 m rising to 1100 m mid day. Saturday: 10-30 cm snowfall temps -3 rising to 0, winds moderate Sw, freezing level 400 m rising to 1200 m mid day. Sunday: no new snowfall temps -8 to -12 winds light to moderate Nw , freezing level 0 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.