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 4th, 2021–Dec 5th, 2021

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

Regions

Jasper.

As natural activity tapers off don't let yourself be fooled. We are entering low probability high consequence state of affairs. November crust is still prevalent and thick to thin spots are of most concern.

Weather Forecast

Sunday: A mix of sun and cloud. Precipn: Nil. Alpine temp: High -17 °C. Mostly light wind occasionally gusting to 35 km/h. Freezing level at valley bottom.Monday: Same as SundayTuesday: Cloudy with sunny periods and isolated flurries. Precipitation: Trace. Alpine temperature: Low -17 °C, High -12 °C. Ridge wind west: 15 km/h. FL at valley bottom.

Snowpack Summary

About 40 cm of snow fell from Nov 30 to Dec 1. Light to moderate SW winds blew the storm snow into wind slabs or stripped windward features to ground. The storm snow came in warm but it surprisingly remains dry and light except at low elevations  where it rained. The midpack is supportive over a crust /facet /depth hoar combo near the ground.

Avalanche Summary

Friday's patrol noted a reduction in natural activity yet a couple of recent size 3's deep slabs running full path were recorded. Thursday's explosive control work observed an avalanche cycle up to size 3 being wind and deep persistent slabs on the ground or the basal crust. Two size 3s were observed at Maligne north of Joffre Creek on Thursday.

Confidence

The weather pattern is stable

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.