Avalanche Forecast

Issued: Dec 29th, 2019 4:00PM

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

Parks Canada a.l. horton, Parks Canada

Email

The snowpack remains weak and stagnant. Stick to low angle sheltered terrain for the best skiing. Avoid steep wind and cross-loaded slopes as dangerous wind slab present there may be easily triggered.

Summary

Weather Forecast

Temperatures will fall into Monday with increasing cloud, light flurries and rising SW winds.  Similar conditions continue on Tuesday.  The cloud and flurries persist into mid-week, however temperatures will gradually warm and winds will ease.

CAA's Mountain Weather Forecast for more specific details.

Snowpack Summary

6-25mm surface hoar growing up to 2200m in sheltered areas. SW winds have created wind slabs on lee features treeline and above. These surface windslabs sit on a variety of buried wind slabs and facetted weak layers. In sheltered areas, the snowpack is weak and faceted. The bottom of the snowpack is also weak with large facets and depth hoar.

Avalanche Summary

No new observations along the Icefields Parkway today.

Confidence

Due to the number and quality of field observations on Monday

Problems

Wind Slabs

An icon showing Wind Slabs

Most fetch zones are stripped and snow has been redistributed to lee slopes and cross-loaded gulleys.  Triggering is likely from shallow spots. Once triggered, the avalanche could awaken weaknesses at the base of the pack creating large avalanches.

  • Avoid steep lee and cross-loaded slopes
  • 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

Possible - Likely

Expected Size

1 - 2.5

Deep Persistent Slabs

An icon showing Deep Persistent Slabs

Whumphing was observed on this weakness below treeline.  This weakness could be triggered by large loads or from thin spots in the snowpack.

  • Watch for whumpfing, hollow sounds, and shooting cracks.
  • Avoid shallow snowpack areas where triggering is more likely.

Aspects: All aspects.

Elevations: All elevations.

Likelihood

Unlikely - Possible

Expected Size

1 - 3

Loose Dry

An icon showing Loose Dry

Ice climbers should use caution in steep confined features where dry loose snow is present above.

  • Use caution above ledges and cliffs where small avalanches may have severe consequences.
  • If triggered dry loose point releases can form deeper deposits in terrain traps.

Aspects: All aspects.

Elevations: Treeline, Below Treeline.

Likelihood

Possible

Expected Size

1 - 1.5

Valid until: Dec 30th, 2019 4:00PM