Avalanche Forecast

Archived

Mar 1st, 2022–Mar 2nd, 2022

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

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.

Reactive storm slabs continue to build at higher elevations and thicker slabs will likely exist on leeward slopes due to wind redistributed storm snow. At lower elevations, loose wet avalanches are likely as rain soaks the snowpack.

Confidence

Moderate - Forecast precipitation (either snow or rain) amounts are uncertain.

Weather Forecast

Strong southwesterly winds result in an onshore flow of a cool, and unstable air mass. This brings moderate to heavy snow at upper elevations for the Vancouver Island ranges and the Coast Mountains.

Tuesday Night: 10-15 mm of precipitation expected with strong southwest winds. Freezing levels 1400 m bringing snow to upper elevations.

Wednesday: Another 10 mm of precipitation falling as snow above 1300 m. Strong southwest wind continues.

Thursday: Drying and cooling trend with the freezing level dropping to 1000 m with light northwest winds at ridgetopn and clearing skies.

Avalanche Summary

On Tuesday, numerous size 1 wet loose avalanches were reported at below treeline elevations. Poor visibility made for limited alpine observations.

On Monday, our field team observed widespread natural avalanche activity size 1-2.5. A skier-triggered size 2 storm slab was reported at Mt Cain on Sunday in this MIN.

Snowpack Summary

The recent storm snow is topped with a thin freezing rain crust and 5 cm of recent moist snow. Within the 40-60 cm of new snow, a wet layer on the surface is stacked on top of lower density, dry snow. This configuration is referred to as upside-down and is often associated with short-term instability while the soft bottom settles. Above ~1900 m, the surface remains dry and has seen extensive wind effect, with extremely variable depths and areas of hard wind slab.

The storm snow sits over a thin layer of weak crystals on a thick, widespread rain crust which makes a great sliding surface for avalanches. This crust is capping a well settled and strong mid and lower snowpack. Shallow snow cover at low elevations leaves many hazards like stumps and creeks exposed at or just below the snow surface.

Terrain and Travel

Minimize exposure during periods of heavy loading from new snow, wind or rain.
Use increased caution at all elevations. Storm snow is forming touchy slabs.
Keep in mind the crust offers an excellent bed surface for avalanches.
Keep in mind that wet avalanches can be destructive due to their high density.

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.