Register
Get forecast notifications
Create an account to receive email notifications when forecasts are published.
Login
Archived

Avalanche Forecast

Dec 23rd, 2021–Dec 26th, 2021
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
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
4: High
The avalanche danger rating in the alpine will be high
Treeline
3: Considerable
The avalanche danger rating at treeline will be considerable
Below Treeline
3: Considerable
The avalanche danger rating below treeline will be considerable

Regions: Waterton Lakes.

The storm has arrived bringing 20 cm snow high winds and warm temps. Over the next few days expect to see storm slabs become more reactive as more snow continues to load weak layers.

Weather Forecast

Friday: Overcast and snowing up to 20 cm. Light NE winds. Alpine temps high -12. Freezing levels valley bottom

Saturday: Overcast and snowing 15 - 20 cm.  Light NE winds. Alpine temps high -16. FL valley bottom.

Sunday: Overcast with flurries, amounting to 5 cm. Light NE winds. Alpine temps high -30. FL valley bottom.

Snowpack Summary

20 cm new snow and variable winds are creating storm slabs and crossloading features.  Warm temps are promoting cohesion of storm slabs. New snow overlies a series of previous windslabs 20-60 cm thick in AL/TL. This sits atop facets above Dec 4 crust. A 20-60 cm thick Nov MFcr complex completes the snowpack to ground. HS at TL is 110 - 170.

Avalanche Summary

No new avalanches reported in park with very limited visibility in the last few days. Operation north and west of the park are reporting several wind slabs up to size 2. If you go out into the mountains please share your observations on the Mountain Information Network.

Confidence

Intensity of incoming weather systems is uncertain

Avalanche Problems

Storm Slabs

20 cm of new snow, variable winds and warm temps are creating a cohesive storm slab. With 20-30 cm more snow in forecast as winds and temperatures decrease we may also see a dry loose problem develop.

  • If triggered the storm/wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Likely - Very Likely

Expected Size: 1 - 2.5

Wind Slabs

Buried wind slabs 20 -60 cm is not bonded well to facets above Dec 4 crust. New load may wake up wind slabs as they reach threshold..

  • Use caution in thin snowpack areas.
  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

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

Elevations: Alpine, Treeline.

Likelihood: Likely

Expected Size: 1 - 2.5

Persistent Slabs

No avalanches observed on this layer this week, however with a large enough trigger this layer could produce results.

  • If triggered the wind slabs may step down to deeper layers resulting in large avalanches.

Aspects: All aspects.

Elevations: All elevations.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3