Avalanche forecast

Sea To Sky

Jan 3, 2017Avalanche Canada
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Archived · expired 10 years ago

Avalanche danger

Tue
Wed
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low
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Highlights

Cold north winds have been blowing. Watch for fresh wind slabs, particularly on southerly aspects

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    Fresh wind slabs have formed on mainly southwest to east aspect slopes in response to extreme northerly winds. Slabs found on south aspect slopes could become more unstable when the sun is out.

Confidence

High - The weather pattern is stable

Weather Forecast

TUESDAY: Dry and sunny. Wind northeasterly 35 km/h. Temperatures around -14C.WEDNESDAY: A mix of sun and cloud. Wind northeasterly 15-35 km/h. Temperatures around -5C.THURSDAY: A mix of sun and cloud. Wind light west. Temperature around -4C.

Avalanche Summary

Small wind slab avalanches could be triggered in recently loaded pockets to size 1.

Snowpack Summary

The critical part of snowpack analysis under current conditions is figuring out how the wind is redistributing snow into wind slabs. Extreme northerly winds have been reported, which will be "reverse loading" wind onto slopes that were previously scoured. I suspect the cold will temper the reactivity of wind slabs on moderate slopes; however, on steep, aggressive terrain, particularly on south-facing slopes in the sun, wind slabs will definitely be in play. Between Monday and Friday last week, 70-100 cm of storm snow accumulated in the region. Below the new snow from this week lies the Boxing Day interface which consisted of wind affected surfaces, faceted (sugary) snow, or surface hoar. Recent observations suggest the overlying snow is generally well bonded to this interface. The mid-December interface is now down 100-150 cm and is generally considered to be stable in this region. Snowpack layers below this are well bonded.

Regions covered