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Avalanche Forecast

Dec 17th, 2023–Dec 18th, 2023
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
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

745 Update: Investigate slopes at and above treeline for buried surface hoar before committing

Few observations in this region. We are unsure how this layer will react to warm weather

Confidence

Low

Avalanche Summary

No recent avalanches have been reported in the region. The buried surface hoar layers show continued reactivity in snowpack testing.

If you're heading out in the backcountry, please consider sharing any observations on the Mountain Information Network.

Snowpack Summary

Warm temperatures and sun may moisten the surface snow and break down crusts likely formed overnight. A widespread crust is buried around 10-20 cm deep, under wind affected snow.

At treeline and above, two layers of concern exist, buried around 30 and 50 cm deep. Both layers consist of a crust that tapers at higher elevations covered by a layer of fragile surface hoar in sheltered areas. No recent avalanche activity has been reported on these layers but they continue to be reactive in snowpack tests. These layers may become reactive to human triggers during the warming.

The snowpack remains shallow for the time of year. Snowpack depths at treeline range from 80 to 120 cm.

Weather Summary

Sunday Night

Partially clear with trace amounts of new snow possible, south alpine wind 20 to 40 km/h, above freezing layer above 1600 m.

Monday

A mix of sun and cloud with no new snow expected, south alpine wind 20 to 40 km/h, freezing level around 2500 m.

Tuesday

A mix of sun and cloud with trace amounts of mixed precipitation expected, southeast alpine wind 10 to 30 km/h, freezing level around 2200 m.

Wednesday

A mix of sun and cloud with trace amounts of mixed precipitation expected, south alpine wind 20 to 40 km/h, freezing level around 2100 m.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Look for signs of instability: whumphing, hollow sounds, shooting cracks, and recent avalanches.
  • Carefully assess open slopes and convex rolls where buried surface hoar may be preserved.
  • If triggered, wind slabs avalanches may step down to deeper layers resulting in larger avalanches.
  • As surface loses cohesion due to melting, loose wet avalanches become common in steeper terrain.

Avalanche Problems

Persistent Slabs

Large surface hoar is buried 30-50 cm deep. Triggering this layer is most likely above 1900 m, and warm temperatures may increase reactivity. Investigate open slopes and convex rolls where buried surface hoar may be preserved.

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

Elevations: Alpine, Treeline.

Likelihood: Possible

Expected Size: 1.5 - 2.5

Loose Wet

Warm temperatures in treeline combined with unexpected overnight precipitation may create a loose wet avalanche problem in snow that was previously dry.

Aspects: All aspects.

Elevations: Treeline.

Likelihood: Possible

Expected Size: 1 - 2

Wind Slabs

Thin wind slabs may continue to be reactivein the alpine, especially where they sit over a crust or surface hoar.

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

Elevations: Alpine.

Likelihood: Possible

Expected Size: 1 - 1.5