Avalanche Forecast

Issued: Jan 1st, 2024 4:00PM

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

Avalanche Canada ahanna, Avalanche Canada

Email

Expect small, easily triggered avalanches on steep slopes in the Monashees, as recent snow is poorly bonded to old surfaces.

A buried weak layer may persist within range of human triggering.

Summary

Confidence

High

Avalanche Summary

  • Small (size 1) loose dry avalanches have been easily triggered by ski cuts in the new snow on Sunday.

  • Explosive control work near Revelstoke on Saturday produced cornice and near-surface slab avalanches size 1.5-2.5.

  • A couple of natural wind slabs size 1-2 and a persistent slab size 1.5 have been reported out of steep, unsupported alpine features in the last few days.

Snowpack Summary

5-10 cm of recent snow (and up to 20 cm in the west Monashees) sits poorly bonded to old surfaces including crusts, surface hoar and facets.

The mid snowpack contains a couple of layers of note; a hard crust formed by an early December rain event around 60 cm deep and a layer of surface hoar 60 to 100 cm deep. Where it exists, the crust effectively bridges underlying weak layers, but the surface hoar remains a concern in areas that do not have the overlying crust.

The lower snowpack is variable throughout the region; in shallower snowpack areas, basal facets may exist.

Weather Summary

Monday night

Partly cloudy, ridgetop wind 20-30 km/h southeast, treeline temperature -8 °C.

Tuesday

A mix of sun and cloud, ridgetop wind 20-30 km/h southeast, treeline temperature -4 °C.

Wednesday

Mostly cloudy with a trace of new snow, ridgetop wind <20 km/h variable, treeline temperature -3 °C.

Thursday

Mostly cloudy with a trace of new snow, ridgetop wind 30-40 km/h variable, treeline temperature -2 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Closely monitor how the new snow is bonding to the old surface.
  • Watch for wind-loaded pockets especially around ridgecrest and in extreme terrain.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.

Problems

Persistent Slabs

An icon showing Persistent Slabs

A layer of surface hoar is buried 60 to 100 cm deep. This layer may be triggerable by riders at upper elevations where it is not bridged by a thick overlying crust.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1.5 - 3

Storm Slabs

An icon showing Storm Slabs

In the Monashees, 10-20 cm of recent snow sits poorly bonded to old surfaces. Small loose dry or thin storm slab avalanches are likely triggerable by riders.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Very Likely

Expected Size

1 - 1.5

Valid until: Jan 2nd, 2024 4:00PM