Avalanche Forecast

Issued: Dec 16th, 2019 4:18PM

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

Parks Canada Conrad Janzen, Parks Canada

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Winds have been whipping in Waterton, be cautious of thin rocky areas where it may be possible to trigger deeper layers.

Summary

Weather Forecast

Tuesday: Cloudy with sunny periods and no new snow. Strong SW winds and a high of -7.

Wednesday: Sun and cloud, moderate SW winds and a high of -5.

Thursday: Flurries depositing 5-10cm of new snow. Moderate SW winds and a high of -6

Snowpack Summary

A true rockies snowpack! Windslabs exist at all elevations, especially in burnt areas. A problematic weak crust facet combo formed in November is down 60cm, and additional crust/facet layers formed in October form the bottom of the snowpack.

Avalanche Summary

Scattered small naturally triggered windslabs have been spotted in lee areas at treeline and below in the past few days.

Confidence

Timing of incoming weather systems is uncertain on Friday

Problems

Wind Slabs

An icon showing Wind Slabs

Strong to extreme winds have stripped fetches in the alpine, leaving very little snow available for transport. Newer wind slabs exist at treeline and below, especially in burnt areas.

  • Be cautious as you transition into wind affected terrain.
  • Be careful with wind loaded pockets. Be aware of wide variation in snowpack depth

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

Elevations: All elevations.

Likelihood

Possible

Expected Size

1 - 2

Persistent Slabs

An icon showing Persistent Slabs

Melt freeze crusts and facets from early season snowfalls are lurking at the bottom of the snowpack. Test results and previous avalanches lead us to believe human triggering of this layer is unlikely, but not out of the question.

  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.
  • Avoid thin rocky or unsupported terrain features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood

Unlikely - Possible

Expected Size

2 - 3

Valid until: Dec 19th, 2019 4:00PM