Regions
Banff Yoho Kootenay.
Winter conditions persist with more snow expected into Tuesday. The hazard is greatest near the divide where the most snow has fallen. Choose more conservative terrain and minimize overhead hazard until things have a chance to settle and bond.
Weather Forecast
Temperatures will remain relatively cool for the next few days, with freezing levels up to 1800m. Snowfall amounts of up to 15 cm near the divide are expected overnight and into Tuesday with a drying trend later in the day. Winds will switch to the West and increase into the moderate range on Tuesday.
Snowpack Summary
10-15 cm of new snow with light winds. Up to 40 cm of storm snow near the divide. Several buried temperature crusts exist to 2000m on all aspects and to ridge tops on solar slopes, including the Mar 15 sun crust down 35-50 cm in the alpine. Moist snow at lower elevations, with the entire snowpack becoming moist near valley bottom.
Avalanche Summary
Some sluffing in the alpine on Monday. Reports of several natural slab avalanches out of steep alpine terrain near the divide up to size 2 in the past 24 hrs. Several skier triggered storm slabs reported near the divide at treeline and above, up to size 2 in the past 48 hrs. Loose wet avalanches up to size 2 at lower elevations in the past 48hrs.
Confidence
Timing, track, or intensity of incoming weather system is uncertain
Problems
Storm Slabs
Storm Slab avalanches are the release of a cohesive layer (a slab) of new snow that breaks within new snow or on the old snow surface. Storm-slabs typically last between a few hours and few days (following snowfall). Storm-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.
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.
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.