Date of Observation: 11/06/2022
Name: Eric Murrow Ben Pritchett
Zone: Northwest Mountains
Route Description: Snowmobile ride from Washington Gulch to Schofield Pass area. Ski tour on the northern end of Cinnamon Mountain.
Observed avalanche activity: Yes
Avalanches: We triggered one small avalanche on a northeast-facing slope, around 11,900′. The avalanche was triggered on a 25-degree slope just off the ridge and propagated into an adjacent wind-drifted feature over 40 degrees in steepness
Weather: Ridgeline Wind Speed: 5-10 mph
Ridgeline Wind Direction: W
Wind Loading: None
Temperature: 33 F
Sky Cover: Overcast
Depth of New Snow: 2 cm
Depth of Total Snow: 60 cm
Weather Description: Warm (just above freezing), snowing lightly (even misting rain off mid day).
Snowpack: We found the November 5th rain crust throughout our trip. Above 11,000 the crust is too thin to play a long-term role, but it’s worth tracking the evolution of this crust below treeline if it remains near the snow surface with cool weather. It could become a problematic faceted crust in time.
Snow height ranged from 20-30cm deep in lower Washington Gulch up to an average 60-70cm deep in wind-sheltered locations near treeline in the Paradise Divide area.
We found recently drifted slabs mostly above treeline, on northerly and easterly-facing slopes near ridgelines. Only the wind-loaded features with a broad and open fetch on their windward side posed a problem. Fresh slabs from the wind on Saturday were generally in the 40-50cm range, resting on a layer of small (1mm) facets.
Wind-sheltered slopes were right-side-up, with denser supportive snow near the ground and soft snow on top.
Photos:
[[accordion id=”my-accordion”]
[accordion_item title=”Avalanche Report #1″ parent_id=”my-accordion” open=”false”]Estimated avalanche date: 11/06/2022
Number of Avalanches: 1
Location
Location: Upper Slate (Purple, Yule Pass, Paradise Divide)
Location Specific:
Start Zone Elevation: ATL: Above Tree Line
Aspect: NE
Characteristics
Trigger: Skier
Trigger modifier: Unintentional
Type: Soft Slab
Failure Plane: Old snow
Size
Relative Size: R1 very small
Destructive Size: D1.5
Avg. crown height (inches): 14
Avg. width (feet): 50
Avg. vertical run (feet): 200
Involvements
# of people caught:
# of partial burials:
# of full burials:
Additional comments:
[/accordion_item]
[/accordion]]
5609