Avalanche forecast

Banff Yoho Kootenay

Dec 20 – 21, 2019Parks Canada
View on map
Archived · expired 7 years ago

Avalanche danger

Sat
Sun
Alpine
4 · High
Treeline
3 · Considerable
Below
2 · Moderate

Highlights

High snowfall amounts and strong winds will elevate the avalanche hazard for the next few days.

Avoid overhead hazard and avalanche terrain.

Avalanche problems

  • Wind Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Very Likely
    Size
    1–2.5

    As the storm intensifies on Friday, expect the incoming snow and strong South West winds to build touchy wind slabs on lee aspects in the alpine and exposed areas at tree line.

  • Loose Dry

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2

    As the snow accumulates, expect sluffing and point releases from steep, rocky terrain and gullies.

  • Deep Persistent Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3.5

    The incoming storm snow will stress the weak, faceted snowpack. Lots of uncertainty surrounds this layer, but if triggered it could result in a large avalanche.

Weather Forecast

The infamous 'atmospheric river' (I wonder who coined that term??) is flowing through our region for the next two days. Forecasts along the Divide predict snow accumulation up to 25cm on Friday, 25+cm on Saturday and another 10cm by Sunday morning. Temperatures will rise as the freezing level reaches 1600m. Winds will be strong from the SW.

Snowpack Summary

Recent strong winds have formed wind slabs in the alpine and exposed tree line areas. The snowpack structure is generally weak, consisting of facets and depth hoar and will be stressed by the incoming storm snow. The Nov crust is present up to 2500m and ~30 cm up from ground. Snowpack depths at treeline range from 80-160 cm.

Avalanche Summary

No new natural avalanche activity in the past few days, though there have been reports of skier triggered wind slabs up to sz 1.5.

Explosive avalanche control at local ski areas have produced sz 1.0 windslabs in steep, wind loaded areas.

Confidence

Intensity of incoming weather systems is uncertain on Friday

Regions covered