Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
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 possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Regions
South Coast.
Confidence
Fair - Due to variable weather conditions
Weather Forecast
Tuesday: Trace amounts of new snow / Moderate southwest winds / Freezing level at 800mWednesday: Light snowfall / Light southwest winds / Freezing level at 900mThursday: Light snowfall / Moderate southwest winds / Freezing level at 1400m
Avalanche Summary
In recent days 2 skier-triggered avalanches were reported having failed on the February 12th surface hoar. For more information, go to our Incident Report database. On Monday a few size 2-2.5 natural slab avalanches were observed on the Coquihalla. Explosives control in the Duffey Lake area produced avalanches of similar size.
Snowpack Summary
Light snowfall on the Duffey and heavy snowfall on the Coquihalla has been redistributed into wind slabs at treeline and above. The new snowfall puts weak surface hoar buried on February 20th up to 70cm below the surface. Where it exists, the surface hoar will likely prolong the reactivity of the recently developed storm slab.On shaded slopes up to 60cm of snow may overlie surface hoar which was buried on February 12th. Most reports of this layer are coming from the Duffey Lake area where observations include whumfing and easy, sudden planar test results. On solar aspects and at lower elevations recent accumulations overlie a series of melt freeze crusts.The mid and lower snowpack pack layers are generally well settled.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.