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

Nov 30th, 2014–Dec 1st, 2014

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

Regions

South Rockies.

What did you see over the weekend? We welcome your observations. Email forecaster@ avalanche.ca.

Confidence

Poor - Due to the number of field observations

Weather Forecast

Monday/ Tuesday/ Wednesday: Very cold and mainly dry. Strong SW winds on Monday, becoming light for Tues/Wednesday.

Avalanche Summary

Explosives triggered two very large (size 2.5 and 3.5) slabs in the south of the region on Thursday around treeline. These failed on a weak layer of facets buried about a week ago. Explosives also triggered some 30-40cm deep size 2 storm slabs on Saturday between 2400 and 2600m on east-facing slopes. The odd naturally-triggered size 1-2 storm slab was also reported over the last few days.

Snowpack Summary

As we begin our forecasting season, we are working with very limited field data. If you have been out in the mountains, we'd love to hear from you. Please email us at [email protected].Half a metre or so of recent snow is likely to have been redistributed by wind into slabs on lee slopes. Natural avalanches may continue spilling down steep headwalls for a day or two. A weak layer (of facets over a crust) which formed during November's dry spell is now buried a metre or more down. Avalanches failing on this layer have the potential to propagate widely, leading to very large events.

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.