Avalanche forecast

Banff Yoho Kootenay

Dec 24 – 25, 2019Parks Canada
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Avalanche danger

Wed
Thu
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable

Highlights

http://www.pc.gc.ca/apps/links/goto_e.asp?destination=http://www.avalanche.ca/spaw/2019-12-23spaw

Avalanche control on Mt. Stephen, Mt Field and Mt Dennis. Please avoid any activity in these areas.

Enter terrain very cautiously and avoid exposure to overhead hazard. Avalanche conditions will take some time to improve.

Avalanche problems

  • Storm Slabs

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

    Storm slabs continue to be reactive Monday. We are seeing widespread avalanche activity releasing from this new load. As the storm snow settles over the next few days natural activity will lessen. Human triggering likely persist for much longer.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely
    Size
    2–3

    The weak, faceted mid and lower pack is overloaded by the new storm snow at all elevations. Avoid exposure to any large overhead hazard.

Weather Forecast

Temperatures will cool  over the next few days with lows dipping down to -20C. Lingering moisture will leave us with mostly overcast skies and light flurries Tuesday. Upper elevation wind values will continue to be in the light to moderate range.

Snowpack Summary

30-60cm of settled storm snow has formed storm slabs all elevations and aspects. At upper elevations evidence new wind transport is visible. Below the new snow the snowpack structure is generally weak, consisting of facets and depth hoar and a Nov crust up to 2500m. These weak layers are getting overloaded with all of the new snow.

Avalanche Summary

Widespread natural avalanche activity to size 3 on all aspects and elevations is mostly 24-48 hours old. Explosive control today continued to produce large avalanches to size 3 running full path. Evidence of light loads initialing large slabs has shown that the snowpack is primed for triggering.

Confidence

Regions covered