Field Report
Grand Mesa - CO
Report Information
A very concerning snowpack structure with unstable results in all snowpack tests and several terrain feature to slope scale collapses and cracks but did not remotely trigger any avalanches even after traveling adjacent to a few steep, north-facing slopes. Although I did not remotely trigger any avalanches, I was not about to go on or underneath any north-facing slopes steeper than 35 degrees that could have produced an avalanche large enough to bury me or drag me into a terrain trap.
Backcountry adjacent to Powderhorn
West out of the Powderhorn ski area boundary descending north-facing slopes then back to the ski area.
Avalanche
Observed an old, remotely triggered avalanche on a northeast-facing slope below treeline and one or two old slab avalanches likely triggered by cornice falls along the mesa rim just east of the Rapid Creek Reservoirs. The rider-triggered avalanche is coded here: https://avalanche.state.co.us/report/9d62cccc-54e4-4bce-89b9-d49570bece88
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Date | # | Elev | Asp | Type | Trig | SizeR | SizeD | Problem Type | Location |
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02/20/2025
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1 | TL | NE | HS | N | R1 | D1 | Wind Slab |
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Date and Time
02/20/2025 -
12:00pm
(estimated)
Location
39.069
-108.187
Avalanche Comments
Likely triggered by a cornice failure |
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Snowpack
The warm temperatures have notably impacted this area, consolidating the 2.4 inches of snow water equivalent [SWE] (manually measured in a snow profile and nearby Snotel sights showed an increase of 2.2" of SWE during the last storm) into a 4F to 1F hard (on the hand hardness scale) slab about 12 to 16 inches thick. Most slopes, except for some steep near treeline north-facing slopes, have melt-water tunnels. Below around 9000 feet, the snowmelt is even more pronounced, with liquid water pooling in concavities and most slopes with wet to moist snow from top to bottom. Although the slab on north-facing slopes was moist, the persistent weak layer of concern, the January drought layer, is still dry. This persistent weak layer shows clear signs of rounding but is composed of such well-developed facets that it will likely remain a concern until it sees notable liquid water and probably a Wet Slab avalanche cycle. Snowpack tests showed a thin but cohesive slab that is easy to trigger and easy to propagate (see SnowPilot profiles).
Weather
Quite warm, above freezing all day and mostly sunny with a moderate breeze along the top of the Grand Mesa.