The timing and intensity of this next system is a little uncertain. Any significant snow or wind event through the day on Tuesday could increase the hazard of slab avalanches on lee aspects at alpine and treeline elevations.
Weather Forecast
Heavy snowfall is forecast for the Columbia Icefields on Tuesday night accompanied by moderate to strong Westerly winds.
Snowpack Summary
Wind slab forming on lee alpine ridge lines. Large surface hoar crystals formed last week are being buried by new snow. This layer is more likely found on sheltered slopes at tree line reaching into the alpine. The interface between the strong mid-pack and weaker basal facets is most susceptible to human triggering from shallow rocky areas.
Avalanche Summary
No avalanches reported today.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Tuesday
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.