Avalanche forecast

Lizard-Flathead

Apr 15 – 16, 2017Avalanche Canada
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Archived · expired 9 years ago

Avalanche danger

Mon
Tue
Alpine
2 · Moderate
Treeline
2 · Moderate
Below
1 · Low

Highlights

Expect the avalanche danger to increase as the sun comes out and temperature rises through the day.

Avalanche problems

  • Cornices

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    2–3
    Cornices are most likely to trigger during periods of intense sunshine and/or the warmest parts of the day.
  • Loose Wet

    • Alpine
    • Treeline
    • Below treeline
    Likelihood
    Possible
    Size
    1–2
    The potential for prolonged periods of sunshine on Sunday will weaken surface snow especially on steep rocky solar aspects.

Confidence

Low - Due to the number of field observations

Weather Forecast

SUNDAY: Mix of sun and cloud / Light southeast wind / Alpine temperature 2 / Freezing level 1700mMONDAY: Cloudy with sunny breaks / Light to moderate south wind / Alpine temperature 5 / Freezing level 2100mTUESDAY: Isolated flurries / Light to moderate south wind / Alpine temperature 4 / Freezing level 2000m

Avalanche Summary

Reports on Thursday indicate numerous skier controlled and natural loose wet avalanches to size 1.5 on all aspects up to 2000m. Additionally a few explosive controlled moist storm slab avalanches were reported to size 2, 20-30cm deep on north and east aspects above 2000m. Exposure to large overhanging cornices remains a significant concern. As the sun comes out over the weekend expect to see cornices weaken and loose snow avalanches run from steep sun exposed slopes during the warmest parts of the day.

Snowpack Summary

Up to 20cm of moist new snow fell at upper elevations Wednesday night. Thursday during the day the precipitation fell as rain up to 2000m making the snow surface moist or wet. Subsequent overnight cooling has created thin surface crusts up to 2100m. All this adds to moist new snow from the previous weekend and sits on a well developed crust layer. The snowpack is generally well settled and continues to transition into a spring melt/freeze regime. Below 1300m the snowpack may be moist or wet through its entire thickness. In the alpine cornices continue to grow large and ever more overhanging.

Regions covered