Avalanche Forecast

Issued: Jan 26th, 2022 4:00PM

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

Avalanche Canada rbuhler, Avalanche Canada

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Lingering wind slabs remain the primary concern in exposed high elevation terrain. Triggering a wind slab is now most likely in steep, unsupported, and/or convex terrain features. 

Summary

Confidence

High - Confidence is due to a stable weather pattern; little change is expected for several days.

Weather Forecast

The ridge of high pressure is currently forecast to persist through Friday with the next storm system arriving Saturday. 

Wednesday Night: Mainly clear with lingering valley cloud, light variable wind, treeline temperature around -6 °C.

Thursday: Mainly sunny with valley cloud, light SW wind, treeline high around -3 °C.

Friday: A mix of sun and cloud with lingering valley cloud, moderate SW wind, treeline high around -4 °C.

Saturday: Mainly cloudy with sunny breaks in the morning and light snow in the afternoon, moderate SW wind, treeline high around -3 °C.

Avalanche Summary

No new avalanches were reported on Tuesday. On Monday, numerous loose snow avalanches (up to size 2) and few wind slabs on cross-loaded features were triggered by strong solar radiation. Evidence of wind slab activity from the weekend has also been observed on steep alpine slopes. On Sunday, a snowmobiler accidentally triggered a large wind slab (size 2.5) on a lee alpine slope. The fracture line was up to 1 m deep. 

A deep persistent avalanche problem in the North Columbia forecast region has produced large and notable avalanches last weekend, and the southeast corner of the Cariboos appears to have a similar lingering problem. On Saturday, explosives triggered a 2.5 deep persistent avalanche on a NE aspect at 2100 m south of Valemount.

Snowpack Summary

Recent strong wind has hit the region hard, stiffening 20-35 cm recent snow in open areas at treeline and throughout the alpine. Isolated surface hoar layers have been observed at the surface or in the upper snowpack (top 100 cm), as well as a thin breakable crust that extends 1600-1800 m (under 20 cm of recent snow), but we have not seen avalanche activity on these layers. Lower elevations have seen spring-like conditions and a sun crust can now be found on steep solar aspects. See our field team photos from the Grizzly Den on Monday.

The lower snowpack is strong and settled in most parts of the region, except the southernmost part of the region around Blue River where there is a deeply buried crust/facet layer that could be exhibiting similar behavior to the deep persistent slab problem in the neighboring North Columbia region. This layer is most prevalent at below treeline elevations and has been reactive to heavy triggers like smaller wind slab avalanches that step down to this layer.

Terrain and Travel

  • Carefully evaluate steep lines for wind slabs.
  • Wind slabs may be poorly bonded to the underlying crust.
  • Small avalanches can have serious consequences in extreme terrain. Carefully evaluate your line for wind slab hazard before you commit to it.

Problems

Wind Slabs

An icon showing Wind Slabs

Recent strong winds have formed slabs in exposed high elevation terrain. Wind slabs have been most reactive where they overlie a thin crust. Expect these lingering wind slabs to remain reactive to human triggering on steep, convex and/or unsupported terrain features. 

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Jan 27th, 2022 4:00PM

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