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Archived

Avalanche Forecast

Dec 5th, 2023–Dec 6th, 2023
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
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold
Alpine
2: Moderate
The avalanche danger rating in the alpine will be moderate
Treeline
1: Low
The avalanche danger rating at treeline will be low
Below Treeline
Below Threshold
The avalanche danger rating below treeline will be below threshold

Avalanche danger is elevated due to heavy snow and strong wind, especially at White Pass.

Watch for rapidly changing conditions as you gain elevation.

Confidence

Moderate

Avalanche Summary

Slab reactivity is expected to increase with incoming new snow and wind on Tuesday night and Wednesday.

During the previous south flow, a large natural avalanche was triggered on a steep north aspect Near Fraser Peak. The crown was up to 100 cm thick, and it was likely a large wind slab.

Early season observations are limited. Please post any pictures or information to the MIN.

Snowpack Summary

At lower elevations, 15-20 cm of storm snow is overlying a thick crust near the surface. Despite the storm, the snowpack remains shallow, with open creeks, exposed rocks, and other early-season hazards.

In the alpine, reports suggest that much more snow has accumulated but is currently redistributed by strong southerly winds. On sheltered and planar slopes, up to 100-125 cm of well-settled snow is topped with 45-60 cm of recent powder. A crust is buried anywhere from 0 to 60 cm, depending on the wind exposure and elevation.

Weather Summary

A quasi-stationary low over the Gulf of Alaska is spinning a moist frontal system up towards the north. Moderate to heavy precipitation and strong winds are expected.

Tuesday night

10-15 cm of snow. Southerly alpine winds increase to 60 km/h. Treeline temperature rising near -2 °C. Freezing levels around 800 m.

Wednesday

5-10 cm of snow. Southerly alpine winds gusting 60 km/h. Treeline temperature -4 °C.

Thursday

Periods of snow up to 2 cm. Moderate southerly alpine winds gusting 50 km/h. Treeline temperature -6 °C.

Friday

Scattered flurries. Moderate southerly winds gusting 50 km/h. Treeline temperature -6 °C.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

  • Storm snow and wind is forming touchy slabs. Use caution in lee areas in the alpine and treeline.
  • Be especially cautious as you transition into wind affected terrain.
  • Avalanche danger is often elevated in alpine gullies where snow has accumulated.

Avalanche Problems

Storm Slabs

Developing storm slabs will become more reactive as the storm progresses. Be careful around leeward and cross-loaded terrain features, such as ridge tops, alpine bowls and gullies where rider-trigger avalanches are likely.

Aspects: All aspects.

Elevations: Alpine, Treeline.

Likelihood: Possible - Likely

Expected Size: 1 - 2