Regions
Vancouver Island.
Confidence
High - weather models agree.
Travel & Terrain Advice
Identify cornices and give them a wide berth when traveling either above or below. Seek terrain options that minimize exposure and vulnerability to overhead hazard and travel on low angled terrain. Avoid terrain traps that will magnify even the smallest of loose wet avalanches. Avoid slopes with freshly load snow, especially during and immediately following wind and snowfall events.
Avalanche Summary
Social media report of a skier accidental on a north aspect @ 1400 meters , not buried and no lost equipment but a close call. Loose wet late in the afternoon skiing alone and with out safety equipment, size one. Numerous loose natural avalanches on steep north aspects have been observed and where expected with the past warming and rain on snow events.
Snowpack Summary
Warm temperatures and rainfall to above 2000 meters have moistened the snow surface on all aspects and elevations from the alpine . Tuesdays snowfall and strong south east winds have deposited in some areas to the lee of this dominate wind, pockets of up to 30 cm, all observed at the treeline. The march 22 melt freeze crust is down now between 90 to 135 centimeters and even though testing only reveals results in the hard range and resistant it still consistently produces a very planar shear. The lower snow pack continues to increase in strength and density.
Snowpack Details
Surface: Moist surface conditions. Upper: Variety of new snow instabilities and density. Mid: March 22 melt freeze crust can be found down from 90 to 135 centimeters. Lower: Well settled and dense.
Past Weather
Warm temperatures high freezing levels and precipitation amounts in the form of rain of up to 35 mm. Beginning early Tuesday, strong sustained south east winds continued most of the day combined with intermittent heavy snowfall. At days end, temperatures cooled and snowfall to 800 meters falling at a rate of 5 centimeters per hour was observed.
Weather Forecast
A parade of low pressure systems to the west of the region will bring to the forecast area, moderate to heavy snow fall , moderate to strong predominately south east wind and below seasonal temperatures. Weather Forecast @1000 meters Wednesday: 15 to 30 cm new snowfall temp 1 , winds moderate to strong south east, freezing level to 1200 m. Thursday: 5 to 15 cm of snowfall temps -6 rising to 0, winds moderate south east, freezing level 0 m rising to 1000 m mid. Friday: 10 to 25 cm of snowfall and 10 to 25 mm of rainfall temps -1 to +3 winds moderate south east , freezing level 500 m rising to 1400 m mid day.
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.
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.