Avalanche forecast

South Coast Inland

Dec 10 – 11, 2017Avalanche Canada
View on map
Archived · expired 9 years ago

Avalanche danger

Tue
Wed
Alpine
1 · Low
Treeline
1 · Low
Below
1 · Low
Open full map

Highlights

Temperature inversion conditions have moistened the snow surface at higher elevations.  This is likely on all aspects in the north of the region and predominantly on southerly slopes in the south of the region.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Increased winds from the south may have produced wind slabs, particularly behind ridges in alpine terrain. Be cautious of firm snow when entering lee features.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2
    Warm air temperatures and clear skies have produced spring-like conditions on steep, sun-exposed slopes. Northerly slopes may also warm up under cloudy skies. Loose wet avalanches may begin small but can grow and push you into dangerous terrain.

Confidence

High - The weather pattern is stable

Weather Forecast

MONDAY: Clear skies, light southwesterly winds increasing to moderate in the afternoon, freezing level around 3700 m with inversion conditions.TUESDAY: Partly cloudy, light southwesterly winds, freezing level around 2300 m with inversion conditions.WEDNESDAY: Mostly clear skies, light northwesterly winds, freezing level rising to 3500 m over the day with inversion conditions.

Avalanche Summary

Numerous loose wet avalanches up to size 2 were observed on northerly aspects along Duffey Lake Road on Sunday. No new avalanches were observed on Friday or Saturday. Numerous small loose wet avalanches (size 1) were observed on steep south and west-facing slopes on Wednesday and Thursday. Glide avalanches were observed on steep, smooth rock slabs to size 2 around the Coquihalla on Thursday.

Snowpack Summary

Warm air temperatures and sunny skies have created surface crusts on southerly slopes, which may melt with warm air temperatures and under sunny skies.  North slopes were also affected in areas where cloudy skies prevailed on Sunday, due to the greenhouse effect.  It appears that this mostly occurred in the northern half of the region.  For the southern half of the region, northerly slopes likely remained cold.  Moderate wind speeds from the south may have produced localized wind slabs on northerly lee features. In shady slopes, surface hoar to 20 mm and near-surface faceting have been observed around treeline and in the alpine.  Cornices may be weakening with the warm air temperatures. The recent snow has formed a strong bond to the late November rain crust, which is now 30-50 cm deep. Treeline snow depths are approximately 1 m throughout the region.

Regions covered