Date of Observation: 02/18/2023
Name: Zach Guy
Zone: Southeast Mountains
Route Description: Cement Creek to Hunter Hill to Carbonate Hill, various aspects to 12,700′
Observed avalanche activity: Yes
Avalanches: Nothing new today. Got a closer look at the large (D2.5) persistent slab reported by Ben yesterday. I estimate the crown was up to 5 feet thick and pencil hard, based on debris chunks. Hard to say what weak layer it failed on, it looks like the bedsurface is a very hard windboard layer, and there were several layers of the wind board onion that peeled off further downslope.
Weather: Few to scattered clouds. Moderate winds above 12,000′ caused light wind drifting in a few areas.
Snowpack: No signs of instability except I triggered a couple of tiny 1″-2″ wind slabs that were forming from today’s blowing snow. I targeted a shallow area on a SE-facing slope above treeline and got hard, propagating results on depth hoar near the ground below a 90 cm, 1F slab. A couple of tests near and above treeline produced non-propagating failures in the recent wind slabs and no failures on the storm interface. There’s about 3 to 5″ of settled storm snow below treeline that’s been redistributed by northerly winds near and above treeline.
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- Thursday’s persistent slab on Carbonate Hill. Note another older avalanche to the left that could be the same problem.
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- Closeup look at the crown, estimated to be up to 5′ thick, pencil hard.
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- Hard slab debris chunks, pencil hard, up to 4 or 5 feet thick.
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- Hard propagating test results on a nearby but shallower slope.
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- 3-4 mm depth hoar; the failure layer in my test pit.
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- Some active wind drifting on Carbonate Hill from today’s moderate winds formed tiny 1″ – 2″ wind slabs.
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- An old wind slab that likely ran last Thursday near Star Pass.
