Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural and human triggered avalanches likely.
Treeline
Natural and human triggered avalanches likely.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
Vancouver Island.
Main concerns: Storm Slab, Loose Wet.
Confidence
Low - Minimal alpine observations.
Travel & Terrain Advice
Avoid avalanche terrain during the height of the warm wet weather on Thursday. Be conservative, especially in wind loaded areas until the recent storm snow has had some time to become more stable. Pay close attention to signs of stability including recent avalanches, shooting cracks or whumpfing.
Avalanche Summary
A break in the weather on Tuesday allowed some alpine and treeline terrain to be viewed. 1 small (size 1) natural storm slab avalanche about 50 cm deep was observed at 1485 m on a north aspect.
Snowpack Summary
The barrage of precipitation and high winds recently has deposited over 2 m of dry storm snow above 1400 m in eastern areas over the last eight days. Expect depths well over 3 m in western areas in the alpine and on the higher peaks of Strathcona Park. This new snow has been slow to settle at higher elevations and includes several poorly bonding weak layers. High winds have produced thick wind slabs in lee terrain in the alpine and open treeline areas. Below 1400 m, periods of rain and elevated freezing levels will have produced moist snow surfaces.
Snowpack Details
Surface: Above 1400 m dry loose storm snow. Wind affected in open areas. Below 1400 m moist to wet snow. Upper: Above 1400 m 60-90 cm of unconsolidated dry storm snow. Mid: Rounding storm snow with varying densities. Lower: Lower 20-30 cm melt freeze crust/facet combo.
Past Weather
60-90 cm of new snow was deposited at treeline elevations and above since the last bulletin. This new snow accumulation was coupled with strong winds mainly from the SE. Freezing levels were around the 1300 m mark with snow levels resting a few hundred meters below that.
Weather Forecast
WEDNESDAY - 15-30 mm of precipitation with freezing levels around 1200 m. Winds moderate from the SW veering SE. THURSDAY - 35-50 mm of precipitation with freezing levels spiking around 1900 m then dropping to 500 m. Winds strong from the west.
FRIDAY - 5-10 mm of precipitation with freezing levels around 600 m. Winds moderate from the SE
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.