Avalanche Forecast

Archived

Feb 28th, 2015–Mar 1st, 2015

Alpine

Natural avalanches unlikely.

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.

Alpine

Natural avalanches unlikely.

Treeline

Natural avalanches unlikely.

Below Treeline

Natural avalanches unlikely.

Regions

Kananaskis.

The "LOW" rating does not rule out all avalanche potential. Avalanches are possible in extreme terrain and on some isolated features.

Confidence

Good

Weather Forecast

Sunday should be a mostly sunny day with light west winds. Temperatures should climb to near -9 in the Alpine. Light snowfalls are expected on Monday as a cold front pushes through and brings below seasonal temperatures.

Avalanche Summary

Nothing new.

Snowpack Summary

The snowpack is highly variable across the forecast region, but some common themes include: widespread wind effect and wind slabs in the Alpine and open areas at Treeline, and various layers of crust found on all aspects below 2000m and much higher on solar aspects. The weak basal layers remain a fixture of the snowpack throughout the region and full depth avalanches are still an outside possibility in certain terrain features. Large triggers such as cornices are the main concern in this respect. Solar input at this time of year is becoming significant, and is causing melt freeze cycles on steeper solar slopes. The extent of these melting periods is variable from day to day depending on climatic conditions.

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.