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Observation: USA Bowl

Observation Date
2/21/2021
Observer Name
Rob J. Lacey S.
Region
Salt Lake » Big Cottonwood Canyon » USA Bowl
Location Name or Route
Big Cottonwood Canyon / USA Bowl
Red Flags
Red Flags
Wind Loading
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments
Dug a pit on SW aspect of USA bowl at about 9800', slope angle of about 23*. HS 93cm. Performed compression test with the following results:
CT3 Q2 @ 86 (overnight snow)
CT11 Q2 @ 55cm
CT18 Q1/Q2 @ 25cm (failed at the PWL)
All of the CT fractures were RP, and the one at 25cm saw the column shift about 2mm downhill before arresting.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Same
Problem #2 Comments
Avoided most east aspects, but found some wind slab at about 9800' while moving from Willow Fork to USA bowl; seemed to be about 1.5cm thick. Only localized cracking where our skis busted through, nothing that propogated.
No large cornices around USA bowl that we saw, but plenty on the west side of Willow Fork on East aspects.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates