Avalanche forecast

Sea To Sky

Feb 8, 2018Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

Forecast snow and strong winds is driving the avalanche danger. Be alert to changing conditions and increased hazard.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5
    Large looming cornices exist along ridgelines. They require respect and discipline. Give them an extra wide berth from above and below.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2.5
    New storm slabs may be reactive to rider triggers, especially on leeward slopes and behind terrain features where wind loading builds thicker slabs.

Confidence

Moderate - Forecast snowfall amounts are uncertain

Weather Forecast

Thursday: New snow up to 20 cm overnight Wednesday. Clearing by the afternoon. Ridgetop winds strong from the southwest. Alpine temperatures near -5 with freezing levels 1600 m. Friday: Mix of sun and cloud with alpine temperatures near -10 and freezing levels at valley bottom. Ridgetop winds light from the north. Saturday: Mostly clear with no forecast snow. Alpine temperatures near -10 and ridgetop winds light from the northeast.

Avalanche Summary

On Tuesday, cornice triggers using explosives produced numerous results up to size 2. Cornices remain fragile, give them a wide berth from above and below. Some loose wet avalanches up to size 1.5 were reported from steeper terrain features below 1700 m. Avalanche activity will likely increase on Thursday with forecast snow and strong winds.

Snowpack Summary

New snow up to 10 cm and consistently strong winds from the south east have formed reactive wind slabs in exposed leeward terrain. Below this is a variety of old snow surfaces including wind pressed, scoured or fresh, low density snow in the alpine. Treeline and below treeline a melt-freeze crust exists with moist snow below 1500 m.An average of 170 cm of settled snow now sits on the mid-January crust which generally shows signs of bonding to the overlying snow; however, it has the potential to "wake-up" with a large trigger such as a cornice fall. Cornices are large and fragile and demand respect. Below this, the snowpack is thought to be generally strong and well-settled.

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