Avalanche forecast

Sea To Sky

Nov 25, 2017Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

Sun
Mon
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
2 · Moderate
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Highlights

With more snow in the forecast, expect storm slabs.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2
    Storm slabs will be most reactive above 1400m where the new snow overlies the recent crust.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–2
    The possibility of triggering a loose, wet slide may still be possible in steep or unsupported terrain. Even a small, wet slide can gain enough mass to become a big problem.

Confidence

-

Weather Forecast

The next wave of warm and wet weather is expected to arrive by Saturday morning with freezing levels forecasted to rise to 2500m on Sunday.Saturday: Snow, accumulation 20-30 cm. Moderate to strong south wind. Alpine temperature -1. Freezing level 1500 m.Sunday: Heavy snow and rain below 2000 m, accumulation 30-40 cm. Strong south wind. Alpine temperature 2, Freezing level 2500 m.Monday: Flurries, accumulation 5-10 cm. Moderate southwest wind. Alpine temperature -5. Freezing level 1000 m.

Avalanche Summary

Wednesday's rain to mountain tops produced numerous, small to very large natural, loose, wet avalanches as rain drenched all elevations. In some areas these avalanches were associated with debris flows and several washouts along FSR roads and trails have been reported. Avalanche activity has since subsided with a return to cooler temperatures and lower freezing levels but will increase again as the new snow and wind build storm slabs at alpine and treeline elevations.

Snowpack Summary

Approximatley 20-30 cm of new snow overlies the November 23 crust This 5-10 cm thick crust can be found on all aspects above 1400 m and overlies a saturated upper pack. Below treeline the snowpack consists of wet snow from top to bottom. In high alpine and glaciated terrain the November 9th layer of weak sugary crystals above a crust near the base of the snowpack is now buried 150 - 240 cm deep.

Regions covered