Avalanche Forecast

Issued: Jan 3rd, 2020 5:00PM

The alpine rating is considerable, the treeline rating is considerable, and the below treeline rating is considerable. Known problems include Storm Slabs and Persistent Slabs.

Avalanche Canada MBender, Avalanche Canada

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The snowpack will take time to adjust to the load from recent snowfalls. In the meantime continue to choose conservative terrain.

Summary

Confidence

Moderate - Forecast snowfall amounts are uncertain.

Weather Forecast

Friday Night: Flurries, accumulation 5-10 cm. Alpine temperature -5 C. Moderate to strong west wind. Freezing level 1400 m.

Saturday: Flurries, accumulation 5-10 cm. Alpine temperature -6 C. Moderate west wind. Freezing level 1100 m.

Sunday: Flurries. Alpine temperature -9 C. Moderate west wind.

Monday: Mainly cloudy with scattered flurries. Alpine temperature -10. Moderate southwest wind.

Avalanche Summary

There was widespread natural and explosives triggered storm and wind slab avalanche activity to size 2.5 and 3 on Wednesday and Thursday. Avalanches were 30-80 cm deep and were reported on all aspects and elevations. Additionally there were several human triggered avalanches reported up to size 2. Some of these were remotely triggered (from a distance).

Snowpack Summary

50-90 cm of new snow fell through the last week. All this recent snow has buried a layer of surface hoar found at all elevations. In some places the surface hoar may be combined with sun crust on steep sun-exposed aspects.

A weak layer that was buried December 26 or 27 is now approximately 100 cm deep and may present as surface hoar in sheltered areas, sun crust on steep solar aspects and/or a melt freeze crust below 1700 m.

An additional layer of surface hoar buried mid December is 110-180 cm deep. Avalanche activity on this layer has tapered off, but there is still concern for heavy loads to step down to this layer. A crust from late November is now over 180 cm deep. Concern for this layer is limited to rocky or variable snowpack depth areas in the alpine where it most likely exists as a combination of facets and crust.

Terrain and Travel

  • Be alert to conditions that change with elevation and wind exposure.
  • Avoid freshly wind loaded terrain features.
  • Be aware of the potential for large avalanches due to the presence of a persistent slab.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Problems

Storm Slabs

An icon showing Storm Slabs

Snowfall continues to accumulate above a recently buried layer of weak surface hoar. Expect storm slabs to remain reactive as the load gradually builds.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Likely

Expected Size

1 - 2.5

Persistent Slabs

An icon showing Persistent Slabs

There is still concern for heavy loads (storm slab avalanches running) to step down and trigger deeper weak layers buried in December.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Possible

Expected Size

2 - 3

Valid until: Jan 4th, 2020 5:00PM