Avalanche forecast

Northwest Coastal

Dec 13 – 14, 2013Avalanche Canada
View on map
Archived · expired 13 years ago

Avalanche danger

Sun
Mon
Alpine
4 · High
Treeline
4 · High
Below
4 · High

Highlights

Forecast heavy precipitation, very strong winds, and rising freezing levels will result in High avalanche danger at all elevations.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    2–5
    The storm continues to develop a deep storm slab at higher elevations due to very strong winds and heavy precipitation.
  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–3
    Rain at lower elevations may saturate the snowpack resulting in moist or wet avalanches.

Confidence

Poor - Due to the number of field observations

Weather Forecast

Tonight and Saturday: Continued warming with freezing levels remaining at about 1500 metres. Expect 15-30 mm of precipitation overnight and another 20-30 mm during the day. Very strong Southwest winds during the storm.Sunday: A moist onshore flow will bring continued snow at higher elevations. The snow line should start lowering during the day, with very strong Southwest winds continuing during the day. Freezing levels dropping back down to about 800 metres by the evening.Monday: Some flurries combined with strong Southwest winds. Freezing levels at about 600 metres.

Avalanche Summary

The warm new storm snow is not expected to bond well to the shallow weak snowpack. Expect natural avalanche activity and easy triggering from skiers and sledders. Steep terrain at lower elevations may experience a cycle of moist or wet natural avalanches releasing at or near the ground, due to forecast rain falling on snow.

Snowpack Summary

Warm and wet Pacific moisture continues to build a storm slab at higher elevations. Rising freezing levels and continued precipitation are expected to create a moist slab above recent buried weak layers that may continue to release naturally. Rain on snow at lower elevations is expected to saturate the shallow snowpack. Very strong to extreme winds are creating deep pockets of wind transported snow at higher elevations.

Regions covered