Avalanche forecast

Banff Yoho Kootenay

Dec 3 – 4, 2024Avalanche Canada
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Avalanche danger

Thu
Fri
Alpine
2 · Moderate
Treeline
1 · Low
Below
1 · Low

Highlights

Warm temperatures may improve comfort levels, but a thin, weak snowpack persists. Elevated winds are expected to load alpine lee areas on Tues. Keep the deep persistent layers in mind, especially on large alpine slopes.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–1.5

    Strong winds are forecasted to persist on Tuesday and are expected to form wind slabs on lee slopes in the alpine. If triggered, these slabs could entrain facets, leading to longer-than-expected runouts.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1.5–2.5

    The October and November crusts, on north and south aspects respectively, can produce deep slabs. Reactive as recently as yesterday at Sunshine Village, these layers are capped by a 50-80 cm slab. Be mindful on steep, rocky alpine slopes where triggering is most likely.

Confidence

Moderate

Avalanche Summary

Lake Louise patrol had minimal results with a few explosive triggered size 1 loose dry avalanches. Otherwise, no new avalanches were observed or reported.

Snowpack Summary

The early-season snowpack at treeline measures 50-90 cm, with heavy wind-affect in the alpine. The November crust lies mid-pack on south aspects, while the main concern is the October crust near the ground on north aspects, where facets and depth hoar are forming. The snowpack is generally weakening as facets develop.

Weather Summary

Mild temperatures with valley lows near 0°C and ridge temps around -4°C expected Tuesday. No snow in the forecast. Winds may intensify into the extreme range from the west, though model confidence is low.

Terrain and Travel Advice

  • Be mindful that deep instabilities are still present in the snowpack.

Regions covered