Observation Date
1/24/2016
Observer Name
Wilson, Hardesty
Region
Salt Lake » Big Cottonwood Canyon » 10420 » West ridge
Location Name or Route
10,420 West Ridge
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
Southwest
Wind Speed
Moderate
Weather Comments
Snowed on and off throughout the afternoon, a mix of graupel, rimed stellars, and unrimed stellars… Perhaps other forms hiding in the mix. Ridgeline winds in the afternoon were on the light side of moderate, certainly strong enough to transport snow and to begin to make stiffer, slabbier consistency of leeward surface snow.
Snow Characteristics
New Snow Depth
8"
New Snow Density
Medium
Snow Surface Conditions
Powder
Wind Crust
Snow Characteristics Comments
Pits on mid elevation N and S, and on high elevation SE and SW failed to reveal instability of snowpack. Two shear planes found within the new snow on wrist and elbow taps, but no propagation and no alarming characteristics. On mid elevation south the snowpack was thinner than in the other pits (~60 cm) and while the facets were weak there was no slab to speak of. Higher elevation pits were deeper (120-160 cm), and revealed more substantial slab and some ECTN results with full arm swing in facets below the Jan 14th crust. Again, nothing alarming. Suspect south facing Gobbler snowpack thinner and weaker than what we saw near Brighton.
Red Flags
Red Flags
Wind Loading
Cracking
Red Flags Comments
No Jan 24 avalanches noted, although there appeared to be debris and a flank from a recent-ish slide on north side of ridge near Lane's Leap. Cracking not noted in wind-protected terrain, but there was substantial cracking on sensitive soft wind slabs: 40’ long and 1 foot deep on a short but steep test slope.
Avalanche Problem #1
Problem
Wind Drifted Snow
Problem #1 Comments
Wind was transporting snow, and we tickled two soft slabs on short-but-steep test slopes, one 40’ wide by 1’ deep, another 12’ wide by 1' deep. Suspect they would have run on longer slope.
Avalanche Problem #2
Problem
New Snow
Problem #2 Comments
Enough new precip for storm snow and dry loose sluffs to be concerning in steep terrain.
Today's 8 inches provided less of a load than the snowpack saw 1/19-1/21. While a persistent slab may lurk, nothing today pointed to it. After finally releasing a hard and stubborn cornice, we watched it push storm snow down a gully without fracturing into lower layers.
Comments
Wind loading just ENE ridgeline made for shooting cracks and slide-ready pockets
Un-exciting photo of under whelming ECT: non-propagating fractures in new snow. After photo, full arm swings got fracture (not clean, no propagation) below visible crust roughly 40cm down
Today's Observed Danger Rating
High
Tomorrows Estimated Danger Rating
Considerable
