Avalanche Forecast

Issued: Jan 27th, 2024 4:00PM

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

lcrawley, Avalanche Canada

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

There is high variability with the amount of precipitation and whether it'll fall as rain or snow.

Rain on snow will rapidly raise the danger.

Summary

Confidence

Moderate

Avalanche Summary

No new avalanches were reported by 4:30 pm on Saturday.

A few small (size 1) storm slab avalanches were triggered on Friday by riders and 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 were reported on Tuesday and Wednesday. Some were remotely triggered from far away..

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.
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

Saturday Night

Cloudy with 5 to 10 cm of snow, south alpine wind 10 to 30 km/h, treeline temperature 0 °C, freezing level 2500 m.

Sunday

Cloudy with 5 to 10 cm of snow or rain, southwest alpine wind 30 km/h, treeline temperature 2 °C, freezing level 2500 m.

Monday

Mostly cloudy with a trace of snow or rain, south alpine wind 25 to 35 km/h, treeline temperature 5 °C, freezing level 3000 m.

Tuesday

Mostly cloudy with 5 cm of snow, south alpine wind 35 to 45 km/h, treeline temperature 3 °C, freezing level 2000 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

The first few hours of rain will likely be the most dangerous period.
Make conservative terrain choices and avoid overhead hazard.
Avoid steep convex slopes.

Problems

Storm Slabs

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

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely - Very Likely

Expected Size

1 - 2

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 MIN reports, one and two, perfectly capture the problem.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

2 - 3

Valid until: Jan 28th, 2024 4:00PM