Observation: Summit

Location: Colorado

Route & General Observations

Colorado to 2300′

Red Flags
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Observer Comments

Moderate to intense snow transport at the north end of Summit Lake zone in the AM; slightly less flagging off peaks and ridgelines in this area than Turnagain Pass on the drive south. Transport died down by the end of the afternoon.

No avalanches from days prior that haven't already been reported in previous obs!

Weather & Snow Characteristics
Please provide details to help us determine the weather and snowpack during the time this observation took place.

Generally clear, with a few high very thin clouds to the far south
Light variable winds, with occasional moderate gusts from the north
Temps in the 20s, though the sun made it feel warmer

Snow surface

8-10" of recent settled new snow, with ski penetration of 4-6". Thin wind skin above 2000' that didn't affect ski quality at all up to our high point at 2300'... though above treeline prior winds have done a number on Colorado and nearby peaks (see two examples below). Recent winds also seemed to have moved more snow around in the 2000' elevation band on neighboring slopes (parts of Fresno and another ridge of Colorado just south of us) as well.

By the end of the day, the edges of the skin track directly facing the sun started to have a thin layer of moist snow, but east facing slopes remained dry. We didn't travel on southerly slopes today, so no observations on more solar aspects!


See below for a pit at 2300' on Colorado, in a spot chosen specifically to check in on the Thanksgiving Crust. Compared to the last pit I dug at this location 5 weeks ago, the Thanksgiving Crust has noticeably degraded and is becoming more fragile/thinner. The facets below the crust are the same size (1 - 2mm) and hardness (4 finger) as before, and are still quite angular under a lens. The loose, 4-finger facet layer directly under the crust was not as thick as observed in weeks prior, and these facets are sitting on a stout layer of large rounded grains (prior melt forms/facets themselves) to the ground. No results in compression tests on this layer, though a PST failed with a cut length of 38cm / 100cm, failing to the end of the block.

No concerning stability test results in layers above the Thanksgiving Crust that are closer to the surface, as depicted in the pit image below!

Photos & Video
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