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 29th, 2020–Nov 30th, 2020

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

Regions

Banff Yoho Kootenay.

Despite the recent strong winds, good skiing can be found in many areas. Avalanche conditions seem pretty good, but a rogue large avalanche on Sunday reminds us of the lurking instabilities in the snowpack.

Weather Forecast

Dry and warm conditions for the next few days. Monday, we may see up to 5 cm of new snow, with winds increasing to strong SW. Tuesday will be dry with decreasing winds from the NW. On Wednesday we may see warm alpine temperatures and the possibility of an inversion.

Snowpack Summary

Variable surface conditions exist with hard windslabs in exposed locations and softer snow in more sheltered areas. The Nov 5 facet/crust combo is down 50-80 cm and producing variable test results, but 'sudden' in fracture character. This crust extends up to 2500 m on N aspects and higher on solar aspects. Snow depths at treeline are 70-130 cm.

Avalanche Summary

Minimal avalanche activity observed today at local ski hills and on a ski tour in the Watermelon Peak area. The exception to this was a large avalanche that was witnessed at around 11 am by a member of the public on the west aspect of Dolomite Peak. It was a size 2.5 that ran in a cross loaded gully feature with minimal weather inputs to trigger it

Confidence

Due to the number of field observations

Problems

Wind Slabs

Wind Slab avalanches are the release of a cohesive layer of snow (a slab) formed by the wind. Wind typically transports snow from the upwind sides of terrain features and deposits snow on the downwind side. Wind slabs are often smooth and rounded and sometimes sound hollow, and can range from soft to hard. Wind 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.

Deep Persistent Slabs

Deep Persistent Slab avalanches are the release of a thick cohesive layer of hard snow (a slab), when the bond breaks between the slab and an underlying persistent weak layer deep in the snowpack. The most common persistent weak layers involved in deep, persistent slabs are depth hoar or facets surrounding a deeply buried crust. Deep Persistent Slabs are typically hard to trigger, are very destructive and dangerous due to the large mass of snow involved, and can persist for months once developed. They are often triggered from areas where the snow is shallow and weak, and are particularly difficult to forecast for and manage.