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Observation: Butler Fork

Observation Date
12/23/2022
Observer Name
Torrey, Graves, Manship
Region
Salt Lake » Big Cottonwood Canyon » Butler Fork
Location Name or Route
Butler Fork
Weather
Sky
Broken
Wind Speed
Calm
Weather Comments
Cloudy and relatively warm temperatures. Light winds. In the early afternoon clouds moved in and dropped to 9500' with cloud deck. A very light misty rain/snow mix occurred around 2:00 pm up to at least 8800' and then later in the afternoon skies tried to clear with blue skies and sun briefly coming through.
Snow Characteristics
New Snow Depth
6"
New Snow Density
High
Snow Surface Conditions
Powder
Snow Characteristics Comments
Wind-pressed surface conditions made for fun and fast skiing.
Red Flags
Red Flags
Poor Snowpack Structure
Red Flags Comments
The poor structure is the biggest red flag observed today. No avalanche activity, collapsing, or cracking was observed.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Decreasing Danger
Problem #1 Comments
We found wind drifts to be generally 6 to 10 inches deep. The interface just below the very obvious dust layer was what we found to be the weakest. Shovel tilt tests produced failure with easy to moderate force and clean, repeatable shears. On a series of small tests slopes, we were not able to cause any avalanching or observe any cracking within the new snow. No evidence of cracking, collapsing, or avalanches in areas we traveled today. North and East aspects were the most common aspects with wind-drifted snow present. Mid and upper-elevation south and west slopes took a beating and lost significant coverage.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #2 Comments
The layer of facets from mid-November is generally buried 50 to 70cm below the surface and ranged from F to 4F hardness. The slab above the faceted layer was consistently 1F to pencil hard. We performed several tests on multiple aspects and results varied. We had multiple ECTx and a couple of ECTP30+. PST's ranged from 30-45/100 END on November facets.
With the lack of recent avalanche activity on this layer and ECT continuing to require more force to fail over the last 10+ days it feels clear this layer is gaining strength and is adjusting to the slab above but don't think we've seen the last of it yet. The upcoming storm with an advertised 2" SWE or more may be a great test to see just how strong this weak layer is.
Snow Profile
Aspect
North
Elevation
9,300'
Slope Angle
26°
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
None
Coordinates