Regions
Banff Yoho Kootenay.
A warming trend is producing uncertainty as to how deep persistent slabs will react in the coming days.
Weather Forecast
Cloud cover and very light precip (<10cm) is forecasted for the next few days. However, wind is expected to be, at times, in the strong range from the west. Temperatures will likely be just below zero at 2000m for the next 24 hours.
Snowpack Summary
60-80cm of storm snow settling with warmer temps has been reactive this past week. Expect moist snow on solar aspects below treeline due to warmer temps and sun. Wind slabs have formed in alpine lee areas. Below this storm snow a more settled slab sits over the weaker facets and depth hoar near the base which is widespread.
Avalanche Summary
A size 2.5 deep persistent slab avalanche was observed on Fossil Mountain today near Skoki Lodge. The slide covered the trail to Cyclone cabin and pushed right up to the trim line. With recent storm snow and warming temps, there was surely much naturally activity through out the region today.
Confidence
Freezing levels are uncertain on Wednesday
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.