Observation: Summit

Location: Fresno Ridge

Date:
Observer:
Route & General Observations

Toured up East aspect of Fresno to 2300′. We found variable surface conditions including breakable melt freeze crusts, sastrugi, thin wind slabs, and softer wind textured snow.

Red Flags
Red flags are simple visual clues that are a sign of potential avalanche danger. Please record any sign of red flags below.
Obvious signs of instability
Recent Avalanches?Yes
Collapsing (Whumphing)?No
Cracking (Shooting cracks)?No
Observer Comments

A large to very large natural wind slab avalanche on a NNE aspect of Summit above treeline. Small natural avalanche on a SW aspect of Butch at ~2500'. Both avalanches looked to have occurred sometime since our last visit to Summit, Monday the 19th.

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

Clear skies, no precipitation, calm winds, mid to upper 20s F.

Snow surface

Variable surface conditions with a melt freeze crust on S & E solar aspects up to 1" thick. This crust was mostly breakable with a few locations that were fairly supportable. Did not get a good look at W or N aspects. Sastrugi, softer wind affected snow, and thin wind slabs (2-4" thick) could be found intermittently over this melt freeze crust.

Snowpack

Pit 1: 2000', E, 27 degrees, HS=110 cm. CT22 SP down 75 cm on facets in between melt freeze crusts. The snowpack, and especially the facets in the lower third of the snowpack, were dry in this location.

Pit 2: 2750', SSE, 19 degrees, HS=153 cm. ECTN 5 down 8 cm on loose rounding facets over a melt freeze crust. CTN. The upper 2/3rds of the snowpack was moist snow. See pit diagram below.

Photos & Video
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