Warm temperatures and upwards of 30cm of storm snow is on its way. Avalanche danger will remain at a seasonal high until this passes.
Weather Forecast
Overnight at the Icefields 5 cm of snow, winds 40 km/h W. Freezing level at valley bottom. Saturday 25cm of snow mostly in the south of the region and at higher elevations. Ridge wind SW 25 km/h gusting to 75 km/h. Freezing level 2100 metres with rain in the townsite. A clearing and cooling trend starts Sunday afternoon, moderate SW winds.
Snowpack Summary
Upwards of 45cm of snow has fallen this week. SW winds are building a reactive wind slab at treeline and above. The mid-pack consists of persistent slab layers intermixed with weak facets. The base is weak facets, depth hoar, and an ice crust from November. A temperature crust exists up to 2000 m.
Avalanche Summary
Numerous large natural avalanches (class 3) were observed from the Maligne area to the icefelds at Tree Line and above. These slab avalanches are failing at varied depths; from recent storm snow to deeper older instabilities. Warm temperatures and precipitation will keep the landscape dangerously active.
Confidence
Freezing levels are uncertain
Problems
Loose Wet
Loose Wet avalanches are the release of wet unconsolidated snow or slush. These avalanches typically occur within layers of wet snow near the surface of the snowpack, but they may quickly gouge into lower snowpack layers. Like Loose Dry Avalanches, they start at a point and entrain snow as they move downhill, forming a fan-shaped avalanche. Other names for loose-wet avalanches include point-release avalanches or sluffs. Loose Wet avalanches can trigger slab avalanches that break into deeper snow layers.
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.