Avalanche forecast

Banff Yoho Kootenay

Nov 27 – 28, 2012Parks Canada
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Avalanche danger

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

The right trigger in the right place can produce deep slab releases down to the Nov. Crust or ground. Stick to moderate slope angles and enjoy. JBW

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–3
    20-40 cm thick soft and hard slabs, reactive to explosives and ski cuts and restricted mostly to immediate lee of ridge crests or in open areas Somewhat isolated and stubborn to trigger

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    The load on this layer is in the critical range. Open areas at treeline have just enough stiffness in the slab to have the potential for deep triggering and propagation. Several Na, skier and explosive avalanches up to size 2.5 in the last 36 hrs.

Weather Forecast

Cool  mainly clear weather through Thursday when pacific onshore flow will bring rising freezing levels and some precipitation.

Snowpack Summary

Last week's storm snow has not had much wind effect and in most places is well bonded and low density. A stellar layer down 30-40 and the November 6 crust down 50-80 are the major weak layers responsible for recent avalanches.

Avalanche Summary

A couple of large deep natural avalanches out of steep alpine terrain have been observed that have failed down to near the ground (Mt. Jimmy Simpson, Mt Rundle.) Explosives are also triggering the odd deep slab (Mt. Lipalian) Early season instability

Confidence

Regions covered