Avalanche forecast

Sea To Sky

Dec 25 – 26, 2011Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
4 · High
Treeline
4 · High
Below
3 · Considerable
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Highlights

Check out the latest post on the Forecaster's Blog for advice on how to stay safe in the backcountry over the holidays.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–4
    Weak windslabs exist below ridge crests, behind terrain features and in cross-loaded gullies.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–4
    Weaknesses are likely within or under the new storm snow and may be triggered naturally (loading from new snow or wind) or by the weight of a person.

Confidence

Poor - Timing, track, or intensity of incoming weather is uncertain

Weather Forecast

A series of frontal systems will affect the region over the next several days bringing periods of moderate to heavy precipitation followed by brief dry spells. Monday: 20-35cm of snow. Moderate to strong S-SW winds. Freezing level (FL) around 800m. Tuesday: 10-15cm. Moderate W-SW winds. FL 1000m rising to 1800m in the evening. Wednesday: 20-30cm. Moderate W-SW winds. FL around 1800m.

Avalanche Summary

Numerous Size 1-2 slab avalanches have been reported in the past 48 hours, primarily in wind affected terrain near ridge crests. Expect the size and likelihood of avalanches to increase through the forecast period.

Snowpack Summary

The region received 20cm of new snow on Friday night and throughout Saturday. Touchy windslabs up to 50cm deep have formed on north through east aspects in response to strong SW winds. A weak rain crust is found below the new snow up to treeline elevations. This crust may sit on top of buried surface hoar and/or facets may persist 10-20cm below. Watch this layer as it gets more load and a thick cohesive slab develops, particularly below treeline where the buried surface hoar would be especially large. A strong mid pack overlies basal facets that have also gained considerable strength. Snow depths are at approximately 140cm at treeline in the Spearhead area and 180cm at treeline in the Brandywine area.

Regions covered