North Rockies Avalanche Forecast - January 21, 2021

Recent snow and extreme southwesterly winds have created touchy wind slabs in many locations, even open areas below treeline. Use caution when transitioning into wind affected terrain.

Thursday

Alpine - Moderate
Treeline - Moderate

Below treeline - Moderate

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Friday

Alpine - Moderate

Treeline - Moderate
Below treeline - Moderate

Saturday

Alpine - Moderate
Treeline - Moderate

Below treeline - Low

Avalanche Summary

On Tuesday, our field team reported widespread wind effect at all elevations, creating fragile cornices and reactive wind slabs on north and east facing slopes below ridgetops. MIN report HERE.

On Monday our field team observed some size 2 natural avalanches on a north facing alpine feature east of Crescent Spur. These likely ran over the weekend.

On Sunday we received some great observations of avalanches running naturally on a crust in the trees in "The Farm" area.

Snowpack Summary

30-50 cm of recent snow and extreme southwest winds have created large, fragile cornices and widespread wind slabs in many locations, even open areas below treeline.

Underneath the recent snow you are likely to find a hard melt-freeze crust that can be found up to about 1600 m. You may also find a weak layer of buried surface hoar in isolated, sheltered locations below treeline. As the new snow continues to settle and form slab properties, these layers could become reactive to human traffic.

Around 60 to 130 cm of snow rests above another weak layer buried in early-December. On Jan 14th our field team found it in the Holmes area. This setup has created a persistent slab avalanche problem and a low probability/high consequence scenario. Depending on location, the buried weak layer is composed of surface hoar and/or a crust/facet combination. Reports suggest that this layer has become dormant in much of the region except for perhaps the Pine Pass area.

Weather Forecast

THURSDAY - Mostly sunny / Light, northwest ridgetop wind / alpine high temperature -10 / Freezing level valley bottom.

FRIDAY - Mix of sun and cloud / Light, northwest ridgetop wind / alpine high temperature -12 / Freezing level valley bottom.

SATURDAY - Cloudy / Moderate, west ridgetop wind / alpine high temperature -12 / Freezing level valley bottom.

Travel and Terrain Advice

  • Watch for newly formed and reactive wind slabs as you transition into wind affected terrain.
  • Avoid lee and cross-loaded terrain.
  • Cornices become weak with daytime heating or solar exposure.
  • Avoid exposure to slopes that have cornices overhead.
  • Cornices often break further back than expected; give them a wide berth when traveling on ridgetops.

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A map of the North Rockies. - Avalanche Canada image
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