CAIC: Colorado Avalanche Information Center BC Zone Observation Report

Tuesday, March 13, 2018 at 12:00 AM
Aspen

Details

Location

Weather

Snowpack

  • Snowpack Obsvervation #1
    • Cracking: None
    • Collapsing: None
    • Persistent Weak Layer: Yes
    • Comments: Patchy snow cover on steep slopes. Spongy but supportable crusts w skim of recent snow. HS up to 75 cm on slopes not receiving such direct insolation. Mushy slabs over soft basal facets. Top 10-15 cm wet, w melt well developed melt forms.
  • Snowpack Obsvervation #2
    • Cracking: None
    • Collapsing: None
    • Persistent Weak Layer: Yes
    • Comments: Hard slabs of variable thickness fill concave slopes and gullies. Probing in one feature showed differences of 50-75 cm over 10 m. Snowpack pencil-knife hard slabs w thin (1cm) soft layers at interfaces. Mostly small rounds, melt forms. Basal DH/ FC grains not large on slope where we dug. No results in DT 22; break. You would have to hit thin spot or edge of lens to trigger slab.

Media

Images

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Figure 1: Snow profile near edge of drifted slope at base of She's Easy. Hard slab over basal weak layer. Would be hard for a person to trigger this slab except where ~ 1/2 as thick. NE-facing, above treeline, West Willow Creek. 3-12-18.
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Figure 2: On this above-treeline slope, thick slabs lie in the gullies, with softer, thinner snow around the rocks. West Willow, 3-12-18.
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Figure 3: Dense, hard slabs lie in the shadowed concavities, with thin snow - potential trigger points - around the rocks. West Willow, 3-12-18.
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Figure 4: On this north-facing, above treeline slope, your most likely to trigger a hard slab of drifted snow from the edges, near the rocks, where the slabs are thinner and softer. 3-12-18.