Avalanche forecast

Glacier

Dec 28 – 29, 2022Avalanche Canada
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Avalanche danger

Fri
Sat
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable

Highlights

Underneath the new storm snow lurks a weak, sugary snowpack...and that sugar ain't sweet, if you know what I mean!

There may be some significant settlement of the snowpack in the coming days, with whumpfing and shooting cracks alerting you to dangerous conditions.

Avalanche problems

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3.5

    Persistent weak layers permeate the upper and mid-snowpack. Step-down crown-lines from the last few days of avalanche activity confirm their sensitivity to additional loading.

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1.5–3.5

    Heavy, warm storm slabs sit atop a weak, faceted early-winter snowpack. Steeper slopes (50*+) have likely shed this slab, but the most "fun" inclines (30-45*) may have held back from avalanching. Stick to supported, lower angle slopes with limited overhead hazard.

Confidence

Moderate

Avalanche Summary

Natural avalanche activity has reduced with the decreased snowfall/winds.

Artillery control on Xmas and Boxing Day had good results, with many avalanches observed in the sz 2.5-3.5 range. There was evidence of step-down avalanches on the persistent weak layers.

Be suspicious of slopes that do not appear to have avalanched in the last few days.

Snowpack Summary

The Xmas storm came in windy and warm, and now this dense, heavy storm slab is squishing down a below-average depth, weak, faceted snowpack.

The storm slab interface (down 55-65cm) was reactive in snowpack tests, while the persistent weak layers (PWLs) were stubborn in tests today at Fidelity.

The reaction of the PWLs to the overlying burden is the thing to watch the next few days. Dig down and test them.

Weather Summary

A gradual cooling and clearing trend sets up for Rogers Pass for the rest of the week.

Tonight: flurries, 5cm, Alp low -6*C, light SW winds, 1200m FZL

Wed: scattered flurries, trace snow, Alp high -6*C, moderate W winds, 1200m FZL

Thurs: sunny periods, trace snow, Alp high -9*C, light SW winds, 700m FZL

Terrain and Travel Advice

  • Back off if you encounter whumpfing, hollow sounds, or shooting cracks.
  • Continue to make conservative terrain choices while the storm snow settles and stabilizes.
  • Storm slabs in motion may step down to deeper layers resulting in large avalanches.

Regions covered