Avalanche Forecast

Issued: Jan 24th, 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 jleblanc, Avalanche Canada

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Identify features of concern where wind slabs will be more prone to triggering, such as convex, steep and unsupported features. 

Summary

Confidence

High - Confidence is due to a stable weather pattern with little change expected.

Weather Forecast

MONDAY NIGHT: Partly cloudy / Light northwest wind / Low temperature -6 C / Freezing level around 1000 m.

TUESDAY: Mix of sun and cloud / Moderate southwest wind gusting at 50 km/h / High temperature -5 C / Freezing level around 1000 m.

WEDNESDAY: Sunny with increasing cloud / Moderate west wind gusting at 50 km/h / High temperature -5 C / Freezing level around 800 m.

THURSDAY: Sunny with increasing cloud / Light south wind / High temperature -2 C / Possible temperature inversion / Freezing level at valley bottom.

Avalanche Summary

Few wind slab avalanches have been naturally triggered over the weekend on cross-loaded alpine features. A small but reactive stiff wind slab caught a rider by surprise at treeline on Sunday. 

A deep persistent avalanche problem in the North Columbia forecast region has produced recent large and notable avalanches, 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 northeast aspect at 2100 m. During last week's warm storm, a few size 2-2.5 deep persistent slab avalanches were observed near Blue River.

Snowpack Summary

Winds have stiffened 20-35 cm recent snow in open areas at treeline and throughout the alpine. A few isolated surface hoar layers have been observed in the upper snowpack (top 100 cm), as well as a thin breakable crust that extends 1600-1800 m (under about 20 cm new snow), but we have not seen avalanche activity on these layers. Lower elevations have seen spring-like conditions and a sun crust can be found on steep solar aspects.

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

  • Use small low consequence slopes to test the bond of the new snow.
  • Carefully evaluate steep lines for wind slabs.
  • Seek out sheltered terrain where new snow hasn't been wind-affected.

Problems

Wind Slabs

An icon showing Wind Slabs

Sustained winds are transporting the recent dry snow and forming fresh slabs on most exposed features. Recent slabs have been most reactive where they overlie a thin crust. Steep, convex and unsupported features will be more prone to human triggering.

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

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

1 - 2.5

Valid until: Jan 25th, 2022 4:00PM

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