Northern San Juan

Avalanche

Jeff Davis Chris Bilbrey · Dec 20, 2019 · Northern San Juan

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Weather

Another beautiful day in the mountains. Northerly winds in the morning were strong enough to move snow in the alpine, but died off in the afternoon. Temperatures in the mid 20's near treeline and in the 30's in the valley.

Snowpack

The alpine has been crush by recent winds. Patchy snowfields observed on windward slopes and larger drifting on leeward slopes. We found cold, dry snow on shady slopes below-treeline while sunny slopes showed signs of warming. In a snowpit on a south-facing slope at 11,500 feet, HS was only 50 cm's. A mixture of crust and facets persist through the snowpack, but individual layers starting to round. A Pencil hard crust sits 20 cm's from the surface and is sandwiched in facets. This layer will have our attention with the next load. In a snowpit on a northeast-facing slope at 11,500 feet, HS was 110 cm's. Near-surface facets down 50 cm's from the surface did not fail in long-column test and showed initial signs of rounding. Facets at the ground (2 to 4 mm) were moist, rounding, and 1F. We did not observe any cracking or collapsing.

Avalanche

No avalanche activity observed.