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Avalanche Forecast

Dec 21st, 2019–Dec 24th, 2019
Alpine
4: High
The avalanche danger rating in the alpine will be high
Treeline
4: High
The avalanche danger rating at treeline will be high
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
2: Moderate
The avalanche danger rating below treeline will be moderate
Alpine
3: Considerable
The avalanche danger rating in the alpine will be considerable
Treeline
2: Moderate
The avalanche danger rating at treeline will be moderate
Below Treeline
1: Low
The avalanche danger rating below treeline will be low

Regions: Waterton Lakes.

Sunday afternoon will bring an end to the storm, but continued overnight wind and snowfall will keep the hazard elevated until freezing levels descend and the snowpack has had time to adjust to the load.

Weather Forecast

Weather models are conflicted on snowfall amounts for Saturday night with amounts between 8 to 20cm expected. Strong winds will continue overnight with a lull on Sunday where we may even see some sun. Freezing level is expected to remain around 1700m descending to valley bottom by Monday night.

Snowpack Summary

60cm+ of wet snow and rain in the Cameron Lake area has arrived with extreme northwest winds and a freezing level around 1900m, continuing to load the snowpack. A 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

A widespread natural cycle was observed on Saturday along the Red Rock and Akamina parkways, with avalanches to size 2 in the storm snow and some larger ones failing on deep persistent weak layers

Confidence

Forecast snowfall amounts are uncertain

Avalanche Problems

Storm Slabs

Continued snowfall accompanied by 120km/h southwest winds has formed touchy slabs

  • Avoid avalanche terrain during periods of heavy loading from new snow, wind, or rain.
  • If triggered the storm slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2

Persistent Slabs

Recent Rain, snow and warm temperatures has begun to overload melt freeze crusts and facets from early season snowfalls causing large avalanches.

  • Avoid exposure to overhead avalanche terrain, large avalanches may reach the end of run out zones.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 2 - 3