Archived

Avalanche Forecast

Dec 4th, 2022–Dec 5th, 2022

Alpine

1: Low

The avalanche danger rating in the alpine will be low

Treeline

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Alpine

1: Low

The avalanche danger rating in the alpine will be low

Treeline

1: Low

The avalanche danger rating at treeline will be low

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

1: Low

The avalanche danger rating at treeline will be low

Below Treeline

1: Low

The avalanche danger rating below treeline will be low

Regions: Coquihalla, Harrison-Fraser, Manning, Skagit, South Coast Inland, Stein.

Carefully evaluate your line for wind slabs before you commit to it.

Small avalanches are possible on isolated lee alpine features.

Confidence

Moderate

Avalanche Summary

Evidence of natural wind slab avalanches (size 1) was reported on Sunday in southeast aspects of the Nak bowl. Several natural slab avalanches (size 1) occurred on smooth rock features near Coquihalla pass this past Saturday. The strong solar warming is suspected to have been the trigger. Keep sharing your observations via the MIN; it helps strengthen our information gathering.

Snowpack Summary

Last week's cold temperatures promoted the development of surface hoar in sheltered and shaded areas at treeline. The upper snowpack consists of 20 to 75 cm of fresh snow, which is now covering a thin melt-freeze crust. Wind-affected snow is found in openings at treeline and above. The mid-snack is consolidated with a series of crust layers and weak faceted crystals underneath. Near the ground, the snow lacks cohesion due to early-season cold temperatures and shallow snowpack. At 1750 m, the snowpack depth is around 130 to 165 cm.

Early season hazards such as rocks and stumps still lurk below the surface. Below treeline is still below the threshold for avalanches.

Weather Summary

An arctic ridge of high pressure will continue to be the main attraction. Conditions will be sunny and dry with a northerly flow pattern. The next frontal system is expected on Wednesday afternoon.

Sunday Night

Clear sky. No accumulation. Moderate northeast ride wind. Low of -12 C at treeline.

Monday

Clear sky. No accumulation. Light northwesterly ridge wind increasing during the day. High of- 8 C at treeline.

Tuesday

Cloudy. Isolated flurries. 2-5 cm. Westerly ridge wind up to 50 km/h. High of -6 C at treeline.

Wednesday

Cloudy. Isolated flurries. Moderate southwest ridge wind. High of -6 C at treeline.

More details can be found in the Mountain Weather Forecast.

Terrain and Travel Advice

Seek out sheltered terrain where new snow hasn't been wind-affected.
Carefully evaluate steep lines for wind slabs.

Avalanche Problems

Wind Slabs

Lingering old wind slabs exist in a variety of lee features. While they tend to stabilize, keep approaching convex and unsupported features with caution.

Aspects: All aspects.

Elevations: Alpine.

Likelihood: Unlikely - Possible

Expected Size: 1 - 2