Avalanche: Summit

Location: Fresno

Route & General Observations

Toured up Fresno to try to get to a crown from a large natural avalanche. We stopped shy of the crown after getting some large collapses on a very weak snowpack, and no good way to cross some big terrain. We dug a pit at 2800′ and found a wet snowpack with a very weak layer of large facets buried about 10″ deep. We saw other natural activity on Twin Peaks and across Colorado Creek.

Avalanche Details
If this is an avalanche observation, click yes below and fill in the form as best as you can. If people were involved, please provide details.
Trigger NaturalRemote Trigger No
Avalanche Type Hard SlabAspect East
Elevation 3400ftSlope Angleunknown
Crown Depth2ftWidth 2500ft
Vertical Run 2000ft  
Avalanche Details

Very large natural on Fresno. I measured the crown width on Google Earth and best estimate is around 2800' wide, 2000' vertical run. Based on our snowpits and multiple hand pits on the way up, the avalanche most likely failed on a layer of advanced facets buried around 2' deep, possibly deeper in some parts of the start zone. The avalanche stepped down to large facets on the ground, leaving large areas totally wiped out down to dirt and rocks. Most likely triggered during strong winds yesterday (12/26).

We saw a large slab avalanche on Twin Peaks (see attached photo) on our drive down, which looked to have been triggered by a small wet loose avalanche. We saw one more fresh slab avalanche across Fresno Creek off of Colorado (photo attached), which was a few hundred feet wide and ran maybe 500' vertical.

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)?Yes
Cracking (Shooting cracks)?No
Observer Comments

Collapsing, fresh very large avalanches, and a lot of liquid water in the snowpack. Scary out there today.

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

23 F in the parking lot when we started skinning, 36 F when we got back to the truck. Noticeably warmer as we gained elevation. Mostly cloudy skies with light westerly winds.

Snow surface

Variable. Areas with old wind slabs were locked up and supportable, areas without old slabs were loose and sloppy. Moisture in the snow for the upper 6-18" of the snowpack, varying largely depending on how firm the snow at the surface was.


See attached snowpit profile.

Photos & Video
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