Avalanche Forecast

Archived

Mar 14th, 2022–Mar 15th, 2022

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches unlikely, human triggered possible.

Below Treeline

Natural avalanches unlikely.

Regions

Little Yoho.

A little more snow in Little Yoho than the Banff bulletin region has raised the danger below treeline. This is primarily due to sluffing in steep gullied terrain. Heads up to ice climbers and couloir skiiers!

Weather Forecast

Steady precipitation over the next few days as the SW flow keeps bringing moisture. An additional 10-30 cm is expected by end of Wednesday. Alpine winds are expected to be moderate to strong from the West throughout. Freezing levels will be ~ 1600m on Tuesday and lowering to ~ 1200m for Wednesday and Thursday.

Snowpack Summary

20-35 cm of new snow sits on a buried sun crust on steep solar aspects, and either previous wind effect or soft snow on other aspects. Several buried sun crust layers exist on steep solar aspects,. but the most concerning have been (Feb 16 down 40-50 cm and Jan 30 down 50-80 cm). The lower snow pack is generally well settled.

Avalanche Summary

Forecasters in the Boom lake area in Kootenay today heard a couple big booms coming out of the obscured steep alpine walls. Likely cornice collapses or wind slab/ dry loose avalanches initiating from snow and wind loading in steep alpine terrain. Local ski hills were reporting windslabs in alpine and treeline terrain, mainly in the size 1-1.5 range

Confidence

Forecast snowfall amounts are uncertain

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.