Date of Observation: 11/30/2022
Name: Eric Murrow
Zone: Northwest Mountains
Route Description: Slate River corridor to Purple Ridge skin track.
Observed avalanche activity: Yes
Avalanches: Widespread natural avalanche cycle. Below treeline northerlies (weakest snowpack) ran during the storm with many small naturals. Near and above treeline slopes held out longer and produced large, dangerous avalanches. See photos. We remotely triggered one avalanche from 250 feet away that wrapped around some small terrain features producing a large (D2) avalanche on a NE slope.
Weather: Clear skies, cool temperatures, and light winds.
Snowpack: We traveled on mostly easterly aspects (NE-E-SE) slopes. Collapsing was rampant on north and east aspects. Some collapses ran a few hundred feet breaking in well-developed facets. The slab ranged from 10 to 15 inches thick in sheltered terrain. The depth, here in the snowbelt Northwest Mountains forecast area, was up to 90cm (3 feet) in sheltered areas. Signs of instability were obvious and the conditions behaved like a Persistent Slab problem with remote triggering a real concern.
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- Looking down at a remotely triggered avalanche. Collapse propagated 250 feet to this slope.
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- Natural avalanches on NW flank of Gothic Mountain
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- Small natural avalanches on westerly terrain near Badly at the head of Slate River Valley.
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- Large natural avalanche in the Martini Couloir on Richmond.
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- Natural avalanches in the east cirque of Schuylkill Peak.
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- Two large avalanches on Purple Ridge.
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- East-facing natural avalanche near Richmond Mountai.
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- Several small natural avalanches.
