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 10th, 2020–Dec 11th, 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.
Below Treeline
Natural avalanches unlikely.
Alpine
Natural avalanches unlikely, human triggered possible.
Treeline
Natural avalanches unlikely.
Below Treeline
Natural avalanches unlikely.

Regions

Banff Yoho Kootenay.

The new snow so far has been less reactive than we thought. Of note, small avalanches may run far if initiated due to the Dec 7 layer, especially as the new snow starts to facet. Good ski quality!

Weather Forecast

High pressure will continue Friday with light winds, and no snow. Temperatures will continue to stay cool in the valley bottoms and in the alpine (-15C)

Snowpack Summary

20-40 cm of low density new snow sits on the december 7th layer of sun crust, facets or surface hoar depending on your location. This new snow came with minimal wind and seems less reactive than we had thought it might be. At the bottom of the snowpack, the Nov. 5th crust / facet layer persists. Snowpack depths are 90-150 at treeline.

Avalanche Summary

We had good visibility in the alpine the last 2 days with field trips and the road patrols of 93S and the TCH Yoho. Sunshine reported a few wind slabs triggered in steep terrain in the new storm snow running on the Dec 7 layer.  Although not large, it has been noted that they have been running far.

Confidence

Due to the number and quality of field observations

Problems

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.

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.