Warm temperatures with possibility of rain on Thursday means that we don't anticipate any decrease in avalanche danger in the short term. Conservative terrain choices are advised.
Weather Forecast
Warming trend continues, accompanied by intense NW winds at ridgetop for next 48 hours. Rain is forecast for Thursday (5mm). Freezing levels rising to 1400m.
Snowpack Summary
Snowpack remains thin and facetted at lower elevations, but is supportive above treeline. Last week's storm snow has buried a surface hoar layer (Jan6) down approx 30cm. Windslabs forming on Southerly alpine aspects and significant snow transport by intense winds.
Avalanche Summary
Numerous size 2 natural soft and hard slab avalanches observed in the alpine and several size 3. Many of these slides are stepping to ground and running to valley bottom. Widespread natural loose dry and spindrift avalanches originating from steep rocky terrain at all elevations. These observations were made in the Columbia Icefield Area.
Confidence
Timing, track, or intensity of incoming weather system is uncertain on Thursday
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.
Loose Dry
Loose Dry avalanches are the release of dry unconsolidated snow and typically occur within layers of soft snow near the surface of the snowpack. These avalanches start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-dry avalanches include point-release avalanches or sluffs.