Stormy weather continues to keep the avalanche danger elevated. Avoid overhead hazards like cornices and steep cliffs where the snow may be weak.
Confidence
Moderate - Freezing levels are uncertain
Weather Forecast
Overnight: Freezing levels remaining above 2200 metres, strong southwest winds, and 2-5 mm of precipitation. Wednesday: Freezing levels around 2000 metres during the day, strong southwest winds, and 5-8 mm of precipitation. Thursday: Daytime freezing level around 1500 metres, moderate southwest winds, and periods of flurries or light snow. Friday: Freezing to valley bottoms, light southwest winds, and mostly sunny with strong solar radiation.
Avalanche Summary
Wind slabs are expected to continue to develop in the alpine above the high freezing levels. At lower elevations, snow may be moist or wet and release easily in pockets of loose wet snow. The possibility of deep persistent avalanches continues during this period of warm and stormy weather.
Snowpack Summary
A warm, wet, and windy storm will form fresh wind slabs at higher elevations while rain with fall below treeline. March has delivered regular storms with roughly 50-90 cm of snow sitting above crust and facet interfaces from February. In some areas the snow above these interfaces may have a poor bond. The mid-pack in this region is generally strong, but the bottom third of the snowpack is composed of weak sugary facets roughly 1-1.5 metres deep. This remains a concern and should be on your radar, especially with the recent loading and ongoing warming.
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.