Avalanche Forecast

Issued: Jan 20th, 2021 4:00PM

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

Avalanche Canada shorton, Avalanche Canada

As the skies clear keep in mind recent snow could still be reactive on steep wind loaded slopes.

Summary

Confidence

Moderate - Uncertainty is due to how quickly the snowpack will recover and gain strength.

Weather Forecast

WEDNESDAY NIGHT: Clear, light northeast wind, treeline temperatures around -8 C.

THURSDAY: Mostly sunny, light northeast wind, treeline temperatures around -5 C.

FRIDAY: Sunny, light north wind, treeline temperatures around -4 C.

SATURDAY: Increasing cloud during the day, moderate northwest wind, treeline temperatures around -8 C.

Avalanche Summary

A steady pulse of storms over the past week has resulted in several widespread natural avalanche cycles. The most recent was on Tuesday with numerous size 1-3 storm slab avalanches at alpine and treeline elevations, especially on wind loaded slopes. In northern parts of the region some of these avalanches stepped down to deeper persistent weak layers and resulted in very large avalanches (size 3-4). See some photos from Monday of avalanches near Shames in this MIN report.

The snowpack should rapidly gain strength with the clearing and cooling weather, making the primary concern lingering storm slabs at upper elevations. If you are travelling to northern parts of the region (e.g. Stewart or Ningunsaw), then persistent slabs should be on your radar as well.

Snowpack Summary

A final storm pulse on Tuesday dumped about 25 cm of snow with extra loading in lee terrain from strong southwest wind. Cooling temperatures has likely formed a surface crust below treeline (roughly 1100 m and below). A total of 100-150 cm of settled snow has fallen in January, which has been helping various early season weak layers to settle and strengthen. In the southern part of the region it appears the early season layers have gone inactive, however there has been regular avalanche activity on weak snow at the bottom of the snowpack in the northern part of the region (e.g. around Bear Pass and Ningunsaw).

Terrain and Travel

  • Don't be too cavalier with decision making, storm slabs may remain sensitive to human triggering.
  • Stay off recently wind loaded slopes until they have had a chance to stabilize.

Problems

Storm Slabs

An icon showing Storm Slabs

The snowpack has seen a huge input of snow and water from successive storms. Storm layers will likely bond, but may just need a bit of time to settle and stabilize. Wind-loaded slopes may remain reactive longer.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1.5 - 2.5

Valid until: Jan 21st, 2021 4:00PM