White Rock Mountain Remote Hard Slab

CB Avalanche Center CBAC Observations

Date of Observation: 01/28/2022
Name: Eric Roberts/ Ben Ammon

Zone: Southeast Mountains
Route Description: 0800-16:45
We toured from Snodgrass TH towards “El Nacho”, descending into Queen Basin. We traveled along the southern ridgeline of White Rock Mountain and descended towards Copper Creek, into Gothic and back to Snodgrass TH.
No major incidents while encountering a variety of conditions. We did not conduct any formal snow tests.

Observed avalanche activity: Yes
Avalanches: During our tour, a hard slab was remotely triggered from approx 50 ft. downslope of an near a 34°Convexity, adjacent to White Rock Mountains southern ridgeline at 12,590’.
Crown ranged from 2”-12”, averaging 8”, 40’ in width.
This potential wind slab moved with building energy as it slid approx. 300’ downslope.
Failure plane was above a stout Melt-freeze crust on small facets. (Not measured)
Skier was not affected, but anyone could have been put off balance if on slope.
Weather: Clear skies AM/PM with valley fog (8,000’) early morning out of forecast area to the south
Calm winds with sporadic, light NW winds ATL
-8°F @ 9,300 (0800) : strong inversion NTL
NO precipitation
Snowpack: Snowpack was a mixed bag at all elevations with the best quality snow being held in wind-sheltered terrain in pockets,
North facing ATL-NTL.
We encountered widespread, audible collapsing BTL initially touring out of East River, but encountered localized collapsing in exposed terrain ATL and along ridge lines.
Wind-packed pockets have slab quality and desperately want to slide but potentially a lack of continuity with some slope to keep them stubborn on exposed, North facing terrain.

Photos:

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