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Avalanche Forecast

Dec 31st, 2023–Jan 1st, 2024
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
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
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
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
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

Check out this blog post for some insight into the current shallow yet complex snowpack.

Confidence

Moderate

Avalanche Summary

A large (size 3), naturally triggered deep persistent slab avalanche in alpine terrain was reported yesterday. It occurred just north of Glacier National Park.

Have a look at this blog post that highlights several recent, similar large avalanches occurring on layers deep within the snowpack.

Snowpack Summary

The upper snowpack is generally well-settled and consolidated with no significant layers of concern.

A layer of surface hoar buried in early December down roughly 50 to 90 cm remains problematic despite any recent signs of reactivity. At lower elevations, a hard crust above this layer may protect it from human-triggering.

The bottom of the snowpack is characterized by weak basal facets.

Currently, the snowpack is particularly complex, with considerable variation across different locations.

Weather Summary

Sunday night

Cloudy with no precipitation, southwest alpine winds 10 to 20 km/h, treeline temperature -5 °C.

Monday

Cloudy with no precipitation, southwest alpine winds 10 to 20 km/h, treeline temperature -6 °C.

Tuesday

Mostly cloudy with no precipitation, southeast alpine winds 10 to 20 km/h, treeline temperature -8 °C.

Wednesday

Mostly cloudy with no precipitation, south alpine winds 10 to 20 km/h, treeline temperature -6 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Avoid steep, rocky, and wind effected areas where triggering slabs is more likely.
  • Keep in mind that human triggering potential persists as natural avalanching tapers off.
  • Uncertainty is best managed through conservative terrain choices at this time.

Avalanche Problems

Deep Persistent Slabs

With basal facets, shallow snowpack areas are the most likely trigger points.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 2 - 3.5

Persistent Slabs

A layer of surface hoar is down 50 to 90 cm; an ideal depth for large, human-triggered avalanches.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Unlikely - Possible

Expected Size: 1.5 - 3