Redistributed storm snow has added weight to windslabs on lee aspects and terrain features. Be cautious of thin areas near ridgecrests.
Weather Forecast
Temperatures are expected to remain relatively warm and will rise above zero in the valley bottoms by Thursday. Some rain may fall near valley bottom. Warm temperatures are expected to stay through the night on Friday. Light accumulations may be in isolated areas in the forecast area as it remains cloudy with sunny periods into the weekend.
Snowpack Summary
Up to 70cm of storm snow has been redistributed by moderate to strong SW winds creating wind slab over a strong mid-pack in lee features on top of a weak basal facets layer at the ground. Warmer temperatures are contributing to settlement in the snowpack. Light flurries may add additional weight to the snowpack.
Avalanche Summary
Natural activity was observed at all elevations in the Icefields area today. The alpine had slabs up to size 2.5 on NE through to SE aspects from 2300m to 2700m. Below treeline, small slab avalanches to size 1.5 occurred on steep open slopes. Monday's field team remotely triggered a size 2.5 from a distance of 20m on a SE aspect.
Confidence
Freezing levels are uncertain on Friday
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.