Avalanche Canada shorton, Avalanche Canada

North Columbia Avalanche Forecast

Jan 14th, 2020 5:00PM

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

Stay warm, navigate around wind slabs, and be cautious of steep open slopes around treeline.

Summary

Confidence

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

Weather Forecast

TUESDAY NIGHT: Clear, light wind from the southwest, alpine temperatures drop to -30 C.

WEDNESDAY: Mix of sun and cloud, light wind from the southwest, alpine high temperatures around -25 C.

THURSDAY: Mix of sun and cloud and isolated flurries with 5-10 cm of low density snow, light wind from the south, alpine high temperatures around -15 C.

FRIDAY: Mix of sun and cloud with isolated flurries and up to 5 cm of snow, light wind from the south, alpine high temperatures around -12 C.

Avalanche Summary

Riders have triggered numerous small (size 1) wind slab, storm slab, and dry loose avalanches over the past few days as well as observe a few larger (size 2) wind slabs in alpine terrain. There have also been several reports of large persistent slab avalanches being reactive to human triggering over the past week. These avalanches have been reported in the Selkirks and the northern tip of the Monashees (near Blue River and Valemount). The avalanches have failed on a surface hoar layer buried roughly 100 cm below the surface, and in terrain between elevations of 1200 to 2100 m on north and east aspects. Examples include a size 3 avalanche that was remotely triggered on Saturday and a size 2.5 avalanche triggered by a snowmobiler in Clemina on Friday (see photo in this MIN report).

Snowpack Summary

As cold arctic air settles over the region expect wind slabs in unusual places due to northerly winds, while sheltered areas still have 20-40 cm of cold powder. A layer of surface hoar is now buried 80-150 cm below the surface and continues to be a concern certain parts of the Selkriks and the northern end of the Monashees. A facet/crust layer from late November lingers near the bottom of the snowpack and has occasionally been reactive in isolated shallow snowpack areas.

Terrain and Travel

  • Don't let the desire for deep powder pull you into high consequence terrain.
  • Use ridges or ribs to avoid areas of wind loaded snow.
  • Approach steep open slopes at and below treeline cautiously, buried surface hoar may exist.

Problems

Wind Slabs

An icon showing Wind Slabs

Likelihood

Possible-Likely

Expected Size

1 - 2

Monitor changes in surface conditions as you travel through terrain as recent wind has formed slabs on a variety of aspects.

Aspects:

All aspects.

Elevations:

Alpine, Treeline.

Persistent Slabs

An icon showing Persistent Slabs

Likelihood

Unlikely-Possible

Expected Size

2 - 3

Lingering concerns remain about a layer of surface hoar buried 80-150 cm below the surface. Activity over the past week suggest this problem is isolated to low elevation clearings in the Selkirks and northern tip of the Monashees (around Blue River and Valemount).

Aspects:

All aspects.

Elevations:

Treeline, Below Treeline.

Valid until: Jan 15th, 2020 5:00PM