Date of Observation: 12/24/2022
Name: Zach Guy and Eric Murrow
Zone: Southeast Mountains
Route Description: Cement Creek and Upper Brush Creek near Pearl Pass, up to 12700′ on various aspects.
Observed avalanche activity: Yes
Avalanches: A handful of previous hard slab avalanches from the arctic blast, D1 to D2, on heavily drifted slopes, generally E to S NTL.
Weather: Calm to light ridgetop winds. Mostly cloudy with periods of light snow. 1″ to 2″ of new snow since yesterday.
Snowpack: The Cement Creek valley floor was not as heavily wind impacted as what I’ve seen in the East River and Slate River corridors. The snow surface remains soft and weak below treeline, ~1mm facets. Once we climbed to near and above treeline, the snowpack got blasted. Snow surfaces are heavily wind affected, ranging from sastrugi to wind board to hard slab. The inch or two of fluffy new snow with no wind affect is a notable potential weak layer to monitor, especially if it facets over the next few days. It’s very low density resting on top of firm, wind hardened surfaces and there was minimal wind drifting it around, so it’s widespread at the moment.
No signs of instability today, though we weren’t messing around on the most suspect, windloaded slopes.
Photos:
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A pair of hard slabs on Carbonate Hill, SE aspects
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This slide failed mostly on a south facing slope (out of view in the sun), but wrapped into a southwest terrain feature and snapped a couple of small trees.
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Hard slab debris near Hunter Hill (E aspect)
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Hard slab near Hunter Hill (SE aspect)
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Hard slab near Crystal Peak (S aspect)
Estimated avalanche date: 12/22/2022
Number of Avalanches: 1
Location
Location: Cement Creek
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: SE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: Unknown
Size
Relative Size:
Destructive Size: D1.5
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Near Hunter Hill
Estimated avalanche date: 12/22/2022
Number of Avalanches: 1
Location
Location: East Brush Creek (Star Pass, Friends Hut)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: S
Characteristics
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: New/Old interface
Size
Relative Size: R2 small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Near Friends Hut. Wrapped onto a SW aspect and broke a few small trees.
Estimated avalanche date: 12/22/2022
Number of Avalanches: 3
Location
Location: East Brush Creek (Star Pass, Friends Hut)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: SE
Characteristics
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: Unknown
Size
Relative Size: R2 small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Carbonate Hill
Estimated avalanche date: 12/22/2022
Number of Avalanches: 1
Location
Location: East Brush Creek (Star Pass, Friends Hut)
Location Specific:
Start Zone Elevation: NTL: Near Tree Line
Aspect: S
Characteristics
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane:
Size
Relative Size: R1 very small
Destructive Size: D1- Relatively harmless to people
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Crystal Peak
Estimated avalanche date: 12/22/2022
Number of Avalanches: 1
Location
Location: East Brush Creek (Star Pass, Friends Hut)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: SW
Characteristics
Trigger: Natural
Trigger modifier:
Type: Hard Slab
Failure Plane: Unknown
Size
Relative Size: R2 small
Destructive Size: D2 – could bury, injure, or kill a person
Avg. crown height (inches):
Avg. width (feet):
Avg. vertical run (feet):
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments: Crystal Peak. Crown no longer visible, D2 debris in gulley. Presumably either S or SW start zone.
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