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

Avalanche Forecast

Dec 21st, 2024–Dec 22nd, 2024
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
1: Low
The avalanche danger rating below treeline will be low
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
1: Low
The avalanche danger rating below treeline will be low
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

Reactive wind slabs exist on all aspects at treeline and above.

Whumpfing, shooting cracks and avalanches are indicators of unstable conditions.

Confidence

Moderate

Avalanche Summary

Some helpful MIN reports from the Shames area describe numerous natural and skier triggered slab avalanches up to size 2. These were on southwest slopes at treeline. The early December crust buried 20 to 50 cm down is a suspect weak interface.

Reactive wind slabs may persist through Sunday.

Snowpack Summary

Recent strong winds have varied in direction, building reactive wind slabs on all aspects at upper elevations. In some areas surface hoar and/or facets are buried 10 to 20 cm below the surface snow. 30 to 50 cm of wind-affected snow rests on a thick rain crust. Reports from the Shames area have noted cracking and whumpfing in the upper snowpack which indicates that they layers require further investigation.

Treeline snow depth range from 200-280 cm. The lower snowpack has no layers of concern.

Weather Summary

Saturday night

Cloudy, with flurries 5 to 10 cm. 25 to 55 km/h southeast ridgetop wind. Treeline temperature -2 °C. Freezing levels 1000 m.

Sunday

Snow 5 to 15 cm. 35 to 70 km/h southeast ridgetop wind. Treeline temperature -3 °C. Freezing levels 700 m.

Monday

Snow 5 to 10 cm. 15 gusting to 65 km/h southeast ridgetop wind. Treeline temperature -2 °C. Freezing level 1000 m.

Tuesday

Snow 10 to 20 cm. 10 gusting to 80 km/h southeast ridgetop wind. Treeline temperature -1 °C. Freezing level 800 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid freshly wind-loaded features, especially near ridge crests, rollovers, and in steep terrain.
  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.

Avalanche Problems

Wind Slabs

Gusty winds are impacting any loose snow, variable winds may have reverse-loaded features. Watch for reactive deposits around ridges or lee features.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2