Dashboard Regions Weather Stations Radar Alerts Glossary
Contact About
Log In

Register for an account and never miss a forecast again!

Register

Avalanche Forecast

Archived

Dec 1st, 2012–Dec 2nd, 2012

Alpine
Natural and human triggered avalanches likely.
Treeline
Natural avalanches possible, human triggered probable.
Below Treeline
Natural avalanches unlikely, human triggered possible.
Alpine
Natural and human triggered avalanches likely.
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.

Regions

Kootenay Boundary.

Confidence

Poor - Due to limited field observations

Weather Forecast

Synopsis: A broad and persistent low pressure center off the BC coast and a steady southwesterly flow over the province will maintain mild temperatures and moderate precipitation for the next few days.Sunday: Moderate snowfall – 10-20 cm, the freezing level is around 1000-1200 m, winds are moderate to strong from the south. Monday: Moderate snowfall – 10-15 cm, the freezing level is around 1000 m, winds are light to moderate from the southwest. Tuesday: Moderate to locally heavy precipitation, the freezing level should jump to 1800 m.

Avalanche Summary

Several natural and skier triggered avalanches up to size 1.5 were reported in the Kootenay Pass area on Friday. Most of these avalanches were 25-30 cm deep and were probably releasing on a surface hoar layer or crust. The size and likelihood of natural and human triggering avalanches will increase with continued precipitation over the next few days. If you and your friends have been out exploring and riding in the backcountry and have some observations to share please send an email to [email protected].

Snowpack Summary

An additional 20-30 cm of heavy new snow has fallen in the past 24 hours. This dense storm snow sits on a crust and/or surface hoar layer, now down 40-50 cm. Recent snowpack tests give consistent easy results on this layer. Given the current weather forecast I would suspect that this layer will be primed for natural and human triggered avalanches for the next few days.In the mid snowpack, there may be a spotty and thin buried surface hoar layer between 50 and 80cm deep. At the base of the snowpack sits the early November rain crust. Located about 100cm below the surface, it seems most likely to be found in deeper snowpack areas and may have associated facets. These layers seem to have been unreactive in recent days, but may have the potential to 'wake-up' with additional loading.In general, snowpack data is sparse in this region and significant variations likely exist from one drainage to another. In short, digging down and making your own observations will be critical to safe slope selection.

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.