Avalanche forecast

Sea To Sky

Mar 31 – Apr 1, 2012Avalanche Canada
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Avalanche danger

Mon
Tue
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–4
    Consistent moderate to strong winds have built hard windslabs in the alpine/upper treeline and soft slabs below. These overlie the slick melt freeze crust and spotty surface hoar.

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    2–6
    Cornices are very large and may become more fragile with the increased load, wind or warm temperatures.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–5
    Recent storm snow will continue to be reactive, especially where it overlies weak layers buried on March 26th. Solar radiation may also trigger storm snow as a slab or as a loose snow avalanche.

Weather Forecast

Sunday: a mix of sun and cloud with light snowfall becoming heavy overnight - moderate southwest winds - freezing level at 850m Monday: heavy snowfall continuing overnight - strong to extreme southwest winds - freezing level between 1000 and 1500m Tuesday: light snowfall with possible clearing - moderate southwest winds - freezing level at 700m

Avalanche Summary

Explosives control on Saturday produced numerous size 1.5-2 avalanches that ran on the March 26th interface. Some of these avalanches ran sympathetically with other slides, or remotely at distances of up to 300m.

Confidence

Good

Snowpack Summary

The latest pulse of precipitation brings the storm snow totals to between 75-100cm overlying surfaces that were buried on March 26. This interface consists of a crust which exists on all aspects except true north facing slopes at treeline and in the alpine, where small surface hoar is present in sheltered places . This week's snow continues to be redistributed by consistently moderate to strong variable winds, forming windslabs in unsuspecting locations. Cornices are huge, and will continue to grow with this weather pattern. Below the March 26 interface, last week's storm snow is well settled and bonded, with further strength gains deeper in the pack. In isolated locations the weaknesses from early February linger and the chance for a large, deep release is possible in times of rapid loading from new snowfall, rain or cornice fall.

Regions covered