Avalanche Forecast

Archived

Mar 1st, 2024–Mar 2nd, 2024

Alpine

Natural and human triggered avalanches likely.

Treeline

Natural and human triggered avalanches likely.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches possible, human triggered probable.

Alpine

Natural avalanches possible, human triggered probable.

Treeline

Natural avalanches possible, human triggered probable.

Below Treeline

Natural avalanches unlikely, human triggered possible.

Regions

Kootenay Boundary, Bonnington, Grohman, Kootenay Pass, Norns, Rossland, Ymir, Crawford, Moyie, St. Mary, Kokanee, Valhalla.

The storm may have passed but dangerous avalanche conditions persist. The snowpack is primed for human triggering. Conservative decision-making remains critical.

Confidence

High

Avalanche Summary

Numerous natural, skier, and remotely triggered avalanches up to size 3 have been reported in the past few days throughout the region. These avalanches failed on layers below the recent storm snow, the mid-February weak layer, and the early-February facet/crust layer.

While natural activity should begin to taper off going into the weekend, human triggering is expected to remain a serious concern.

Snowpack Summary

Up to 70 cm of storm snow has accumulated over the past week. This new snow has formed touchy slabs, especially in wind-exposed terrain, and may sit over a weak interface in some areas.

A weak layer of facets, surface hoar, and/or a crust from mid-February may be found down 40 to 80 cm.

A widespread crust formed in early February is buried roughly 60 to 100 cm and extends up to 2400 m. Weak facets have been found above this crust. This layer has produced many concerning avalanches across the province.

The lower snowpack is generally well-settled and strong.

Weather Summary

Friday Night

Mostly cloudy with 2 to 10 cm of snow. 10 to 30 km/h southeast ridgetop wind. Treeline temperature -8 °C.

Saturday

Mostly cloudy with 2 to 10 cm of snow. 10 to 30 km/h southeast ridgetop wind. Treeline temperature -8 °C.

Sunday

Mostly cloudy with 0 to 2 cm of snow. 10 to 30 km/h southwest ridgetop wind. Treeline temperature -10 °C.

Monday

Mostly cloudy with 1 to 5 cm of snow. 0 to 20 km/h southwest ridgetop wind. Treeline temperature -10 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Fresh snow rests on a problematic persistent slab, don't let good riding lure you into complacency.
Remote triggering is a concern, watch out for adjacent and overhead slopes.
Only the most simple non-avalanche terrain free of overhead hazard is appropriate at this time.
Keep in mind that human triggering potential persists as natural avalanching tapers off.

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.