Avalanche forecast

Waterton Lakes

Jan 25 – 28, 2016Parks Canada
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Archived · expired 11 years ago

Avalanche danger

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

While Wind Slab predominates , uncertainty exists about the sensitivity of buried weak layers - a cautious approach is recommended at Alpine and Treeline elevations.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    Buried Wind Slabs are widespread in exposed areas, and are largest in the SW of the Park. These are hidden under recent snow, and touchier new Wind Slabs. Use extra caution on lee slopes - clues include cornices up above, and a deep snowpack.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Unlikely - Possible
    Size
    1–3
    A weak layer that was buried in early January was showing signs of strengthening before Fridays' storm, but has not been ruled out as the potential failure plane of several large, recent slab avalanches. Consider avalanche consequence at all times.

Weather Forecast

A mix of sun and cloud with isolated flurries daily. Freezing levels will hover around valley floor, rising slightly higher by Wednesday. Ridge winds are forecast at Moderate from the W-SW, rising to strong by Wednesday.

Snowpack Summary

15cm of new fluff sits on Fridays' Rain Crust below 2100m, and on thick, dense Wind Slabs above this. Forecast wind will build new wind slabs in lees. The primary concern, though, are old Wind Slabs. These may propagate widely, especially if they initiate on/step down to a weak layer buried 40-80cm: Crust on solar aspects, Surface Hoar on shady.

Avalanche Summary

Two large Slab avalanches were observed today on lee N-E aspects, initiating around 2300m. These are likely Wind Slabs, but could be on the Jan 4 Surface Hoar. Earlier, a widespread natural cycle of small avalanches was observed during Fridays warm storm, with a few isolated large avalanches. One of these was a persistent slab on the Jan 4 crust.

Confidence

Due to the number and quality of field observations on Sunday

Regions covered