Avalanche Forecast

Issued: Feb 1st, 2017 4:00PM

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

Avalanche Canada stephen holeczi, Avalanche Canada

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Little Yoho.

We have moved to a "Moderate" rating due to lack of natural activity. Keep in mind that the snowpack is weak in many Little Yoho locations, and large avalanches are still possible. If there is a slab overlying facets, its suspect. SH

Summary

Weather Forecast

Lows of -20c and highs of -15C for Thursday with light N winds and no new snow.  Currently a big storm is in the forecast for this weekend, but we have all heard that one before...  stay tuned.

Snowpack Summary

Wind slabs formed from strong winds this week. A generally weak snowpack exists below 2000-2200m. At 2000m, there is generally 140 cm of snow, with the Jan 17 surface hoar layer down 30cm. In the mid-pack, the Dec facets are around 20cm thick, and near the ground some weak facets sit just below an ice crust. More solid snowpacks exist above 2200m.

Avalanche Summary

There was a small avalanche cycle this past weekend from strong winds.  The activity has slowed significantly due to decreased winds and cooling temperatures.  No avalanches reported Wednesday.

Confidence

Timing, track, or intensity of incoming weather system is uncertain on Saturday

Problems

Persistent Slabs

An icon showing Persistent Slabs

The generally weak, facetted mid pack is producing moderate to hard shears. In the upper snowpack around treeline a buried layer of surface hoar produces variable shears. Increased slab development overlying these layers is likely with recent winds.

  • Use conservative route selection, choose moderate angled and supported terrain with low consequence.
  • Dig down to find and test weak layers before committing to a line.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Wind Slabs

An icon showing Wind Slabs

Wind slabs exist in the immediate lees which are decreasing in sensitivity to triggering.

  • Use caution in lee areas. Recent wind loading have created wind slabs.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

1 - 2

Valid until: Feb 2nd, 2017 4:00PM

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