Avalanche forecast

Banff Yoho Kootenay

Apr 17 – 18, 2018Parks Canada
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Avalanche danger

Thu
Fri
Alpine
3 · Considerable
Treeline
2 · Moderate
Below
2 · Moderate
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Highlights

A surge of moderate to strong SW wind today created fresh windslabs and have loaded cornices.  Choose conservative terrain and minimize exposure to overhead hazard until the snow has a chance to bond.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2
    20-50 cm of storm snow has fallen over the past few days with the greater amounts near the divide.  Increased SW wind Tuesday afternoon loaded lee terrain creating reactive windslabs.

  • Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    While it has been several days since there have been any confirmed events directly associated with the March 15 crust, other temperature crusts have now become buried in similar locations and are providing a good sliding layer for the new storm snow.

  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible - Likely
    Size
    1–2
    Lower elevations may see loose wet avalanches start to occur later in the day with either temperature increases or with solar input as skies clear late Wednesday.

Weather Forecast

Temperatures will remain relatively cool, with cloudy skies and with freezing levels up to 1800m for Wednesday. Winds should diminish through the day as skies clear Wednesday evening and a high pressure builds in the region.

Snowpack Summary

Up to 50 cm of storm snow near the divide affected by moderate SW winds Tuesday afternoon. Several buried temperature crusts exist to 2000m on all aspects and to ridge tops on solar slopes, including the Mar 15 sun crust down 35-50 cm in the alpine. Moist snow at lower elevations, with the entire snowpack becoming moist near valley bottom.

Avalanche Summary

Touchy windslabs 10-40 cm thick developed Tuesday afternoon with moderate to strong SW wind.  A few natural avalanches were observed and windslabs were reactive to ski cutting and explosive control. 

Confidence

Regions covered