Regions
Banff Yoho Kootenay.
Wind and new snow will begin to push the Danger towards HIGH on steep loaded features. Stick to low angle terrain with low consequences. JBW
Weather Forecast
Another storm Friday will bring up to 10cm west of the divide with lesser amounts eastwards. Winds will continue to be in the Moderate to Strong range from the west. temperatures will cool with the passing of the front Friday/Saturday.
Snowpack Summary
Up to 10cm new snow has fallen west of the divide. Otherwise, the winds have been howling from the west and all windward slopes are stripped bare. Lee and cross loaded gullies have a mix of hard and soft wind slabs over a weak shallow base.
Avalanche Summary
No new avalanches have been observed over the last 24 hrs. Sporadic natural avalanches up to size 2.5 have been occurring this past week on steep slopes with wind loading.
Confidence
Wind effect is extremely variable
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.