Avalanche Forecast

Issued: Jan 26th, 2024 4:00PM

The alpine rating is considerable, the treeline rating is moderate, and the below treeline rating is moderate. Known problems include Persistent Slabs and Storm Slabs.

lcrawley, Avalanche Canada

Kootenay Boundary, Crawford, Moyie, St. Mary, Bonnington, Grohman, Kootenay Pass, Norns, Rossland, South Okanagan, Ymir.

Persistent problems are best managed with patience and conservative terrain choices.

Choose terrain without terrain traps, free from overhead hazards.

Summary

Confidence

Moderate

Avalanche Summary

A few small (size 1) storm slab avalanches were triggered on Friday, with explosives.

On Thursday there were a few small (size 1-1.5) storm slab avalanches west of Winlaw. North aspect, treeline, 35 cm deep.

Numerous natural and human-triggered large (size 2) avalanches, 30 to 90 cm deep, were reported on Tuesday and Wednesday. Some were remotely triggered from far away. The activity was on all aspects, treeline and above, and often involved buried facets.

Snowpack Summary

The snowpack has two buried weak layers of concern:

A layer of facets and surface hoar buried 30 to 60 cm deep, covered by a thin crust at lower elevations but remaining active higher up. This started as a storm slab and has persisted as a problem.
A crust and facet combo from the new year down 80 to 100 cm. This layer seems to be becoming active now that it has a significant load over it from the continued trickle of snow.

Currently, the mid and lower snowpack is generally well-bonded, featuring a thick crust near its base.

Weather Summary

Friday Night

Cloudy with up to 5 cm of snow, southwest alpine wind 20 to 40 km/h, treeline temperature -4 °C.

Saturday

Cloudy with up to 5 cm of snow, southwest alpine wind 10 to 30 km/h, treeline temperature -2 °C, freezing level 1500 m.

Sunday

Cloudy with 15 to 20 cm of snow or rain, southwest alpine wind 30 to 50 km/h, treeline temperature 3 °C, freezing level 2700 m.

Monday

Mostly cloudy with 5 cm of snow or rain, south alpine wind 30 to 50 km/h, treeline temperature 4 °C, freezing level 3000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Make conservative terrain choices and avoid overhead hazard.
Avoid steep convex slopes.
Be carefull around freshly wind loaded features.

Problems

Persistent Slabs

There are two layers of concern: Surface hoar and facets buried 30 to 60 cm deep, and facets over a crust 70 to 100 cm down. These layers need more time to heal. These MIN reports, one and two, perfectly capture the problem.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Possible - Likely

Expected Size

2 - 2.5

Storm Slabs

Expect storm slabs to be the deepest and most reactive where the snow has been affected by the wind.

Aspects: North, North East, East, South East, North West.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 1.5

Valid until: Jan 27th, 2024 4:00PM