Avalanche forecast

Banff Yoho Kootenay

Nov 24 – 25, 2012Parks Canada
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Avalanche danger

Sat
Sun
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

Avalanche Control on Saturday for the Sunshine Road, please no climbing in the area.  Considering control work for Bosworth and Stephen in Yoho and possibly Whymper  in Kootenay on Sunday, stay tunned. (LP)

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    1–2
    20-40 cm thick soft and hard slabs, reactive to explosives and ski cuts and restricted to immediate lee's. Slab was stiffer today with longer propagations, but still in the size 2 range.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–3
    May be reaching the tipping point for this layer.  A size 2.5 was ski cut in the Wizard chutes on the backside of Wawa ridge near Sunshine.  Thursday, a full depth release down to ice was noted on the Monarch Glacier (Sunshine backcountry).

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    40-50 cm settled storm snow with an easy shear on the old snow surface.  Primarily an issue on steep terrain features, especially if it's an open feature exposed to some wind effect.  Give it a few days to settle and bond. See forecast details.

Weather Forecast

The mod to strong SW winds should abate by midnight and flip to a lighter NW flow & cooler temps (-10).  Trace precip tonight. Unsettled tomorrow, with sunny periods.  High pressure settles in Sunday with clearer skies forecasted.

Snowpack Summary

Since Nov 18th there has been 40-50 cm of new snow along the divide, lots still available for transport. Easy shears at the storm snow interface. There are mod shears on Nov 6 rain crust in the lower third of the pack.  The crust exists throughout the region and can be found up to 2400 m.

Avalanche Summary

One notable skier cut size 2.5 avalanche in the Wizard chutes, NW aspect, at 2100 m, on 35-40 degree terrain - 60 cm thick soft slab, propagated 75-80 m, likely slid on the crust & ran 300 m. Generally poor visibility today for avy observations.

Confidence

Due to the number of field observations

Regions covered