Avalanche forecast

Kootenay Boundary

Apr 1 – 2, 2018Avalanche Canada
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Avalanche danger

Tue
Wed
Alpine
3 · Considerable
Treeline
3 · Considerable
Below
3 · Considerable

Highlights

New snow amounts could be highly variable into Monday. If you see more than 30cm of new snow (especially if it sits on a firm crust) the danger is HIGH and it's best to avoid all avalanche terrain.

Avalanche problems

  • Storm Slabs

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Likely - Very Likely
    Size
    1–2.5
    Extra caution is advised where heavy snowfall sits on a firm melt-freeze crust... a perfect sliding layer for slab avalanches.

Confidence

Low - Intensity of incoming weather systems is uncertain on Monday

Weather Forecast

Forecast amounts of new snow are uncertain on Sunday into Monday. Local amounts of new snow may be highly variable, with the north of the region possibly seeing areas with 20-35cm accumulation into Monday.SUNDAY NIGHT: Some areas may see localized very heavy snowfall (20-35cm possible), where neighbouring areas may see only 5-10 cm, if that. MONDAY: Cloudy with some lingering flurries ending near noon (5-10cm) / Light northerly wind / Alpine temperature -8 / Freezing level 900m TUESDAY: A mix of sun and cloud / Light to moderate west wind / Alpine temperature -6 / Freezing level 1200m WEDNESDAY: Cloudy with some flurries (5-10 cm during the day) / Light to moderate south west wind / Alpine temperature -4 / Freezing level 1300m

Avalanche Summary

On Friday, cornice control work resulted in triggering a size 2 wind slab below, on an east aspect near 2200m. Slab depth averaged 20cm.

Snowpack Summary

Warm temperatures and sun over the long weekend resulted in moist snow on sunny aspects, and firm crusts when the surface froze overnight. 30-60 cm of snow from last week sits on a crust at all elevations on solar aspects and all aspects below 1900 m elevation. Winds were moderate to strong from the north west on Wednesday (switching to southwest by Friday), creating fresh wind slabs on down wind (lee) aspects at higher elevations. On northerly aspects at and above tree line the old storm snow is burying a mix of large surface hoar and surface facets. Another weak layer buried mid March is down 50 to 80cm and is a crust on solar aspects and surface hoar (to 6mm) on high elevation north. The surface hoar is still giving sudden collapse test results.A few other persistent weak layers are buried in the mid and lower snowpack, but they have gone dormant and are unlikely to resurface until we move into a period with consecutive above-freezing nights.

Regions covered