Conditions are variable across the region. The Flathead and southern Elk Valley may have similar conditions to the Lizard Range at present (so check the Lizard Range bulletin too).
Confidence
Fair - Forecast snowfall amounts are uncertainfor the entire period
Weather Forecast
Monday: Mainly light snowfall starting in the afternoon. Winds picking up to strong south-westerlies. Tuesday: Some lingering flurries possible. Cold.Wednesday: Light to moderate snowfall. Moderate to strong south-westerly winds. Freezing level at valley bottom.
Avalanche Summary
Skiers triggered small pockets of wind slab and heard some rumbling yesterday, but visibility remained poor for observations. A smattering of avalanches involving persistent weak layers occurred throughout the region earlier in the week, on north-east aspects at treeline and above.
Snowpack Summary
The snowpack in the South Rockies region varies considerably at present, with the Southern Elk Valley and Flathead Ranges close in nature to the Lizard Range. Near the Crowsnest, it's been drier and more consistently windy. Castle Mountain has been having its own little party and getting locally heavy snowfall. Anywhere from 4-30cm of new snow has fallen, redistributed by strong south-westerly winds into soft and hard wind slabs on lee slopes, followed by further snowfall with no wind. Old wind slabs appear to be gaining strength, however new ones could form quickly if the wind picks up again. Besides new storm/wind-related concerns, the layer we're still watching in the region is a surface hoar layer buried in early December. It's down about 85cm in the Flathead and exhibits hard, sudden planar/full propagation results, meaning that's it's stubborn to trigger but could create a large avalanche if triggered.At the bottom of the snowpack a variable facet/crust/facet sandwich is located with depth hoar up to size 5mm below the crust, and facets size 2mm above. There has been little in the way of recent activity on basal layers.
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.
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.
Persistent Slabs
Persistent Slab avalanches are the release of a cohesive layer of snow (a slab) in the middle to upper snowpack, when the bond to an underlying persistent weak layer breaks. Persistent layers include: surface hoar, depth hoar, near-surface facets, or faceted snow. Persistent weak layers can continue to produce avalanches for days, weeks or even months, making them especially dangerous and tricky. As additional snow and wind events build a thicker slab on top of the persistent weak layer, this avalanche problem may develop into a Deep Persistent Slab.