Natural avalanches possible, human triggered probable.
Treeline
Natural avalanches unlikely, human triggered possible.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural and human triggered avalanches likely.
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 Columbia.
Confidence
Fair - Intensity of incoming weather is uncertain for the entire period
Weather Forecast
Friday: Moderate snowfall / Moderate southwest winds / Freezing level at 1500mSaturday: Heavy snowfall / Moderate southwest winds / Freezing level at 1400mSunday: Light snowfall / Light southerly winds / Freezing level at 1100m
Avalanche Summary
No recent avalanche activity to report. We welcome all field observations at [email protected].
Snowpack Summary
Up to 10cm of new snow fell on Wednesday night with light to locally moderate south/southwesterly winds. Forecast wind and snow will add some punch to this developing wind/storm slab which sits over a variety of surfaces that may include surface hoar, a sun crust on steep solar aspects, and well settled storm snow from last week. Deeper in the snowpack you might find a thin, spotty surface hoar layer between 50 and 85 cm down. As well, the early November rain crust now sits over 100cm down in most locations (at treeline and above) and may exist in combination with facets. These layers seem to have been unreactive in recent days, but may have the potential to 'wake-up' with additional loading.The snowpack depth in the alpine ranges from 130-225 cm. Treeline near 150 cm.
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.