Regions
Vancouver Island.
Confidence
High - forecast models, generally align.
Travel & Terrain Advice
Utilize terrain to minimize exposure to recently loaded slopes and overhead hazard such as cornices. Seek low angle terrain and areas shelter from the wind.
Avalanche Summary
Explosive avalanche control reports from Mount Washington on Sunday February 18 produced numerous results. On steep north aspect in areas protected from wind, ski cutting produced up to size 2 avalanches. Explosive avalanche control produced on north east aspects, avalanches up to size 2. All of the avalanches failed on the old melt freeze surface buried on February 14. These avalanches were primarily slab avalanches, however in a few spots , they were loose dry avalanches.
Snowpack Summary
Two snowfalls over the previous forecast period have buried any past exposed melt freeze crust. The new snow fell during cool temperatures and winds were moderate from both the north east and west. The upper snow pack is cold, light and dry. Moderate bonding has occurred at the melt freeze crust, however light snow has been continually transported and lee aspects/ south aspects have seen a rapid load over the last 48 hours creating a noted instability. Below the melt freeze crust and well settled and strong snow pack exists.
Snowpack Details
Surface: Low density, light and dry. Upper: Melt freeze crust. Mid: Well settled. Lower: Well settled.
Past Weather
Cool temperatures, moderate snowfall and north western wind rounded out the past weekend. Snowfall was light and dry with amounts any where from 20 cm to 55 cm.
Weather Forecast
Monday: no new snowfall temps -15 to -4, winds moderate north west, freezing level 0 m rising to 300 m mid day. Tuesday: no new snowfall temps -12 rising to -6, winds moderate north west, freezing level 0 m rising to 200 m mid day. Wednesday: no new snowfall temps -14 to -5 winds light to moderate north west , freezing level 0 m rising to 300 m mid day.
Problems
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.
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.