Observation: Grizzly Gulch

Observation Date
11/27/2019
Observer Name
Bo Torrey
Region
Salt Lake » Little Cottonwood Canyon » Grizzly Gulch
Location Name or Route
Grizzly, East Pass, Cottonwood Ridgeline
Weather
Sky
Overcast
Precipitation
Moderate Snowfall
Wind Direction
Southeast
Wind Speed
Strong
Weather Comments
Weather was the main story today. Strong South winds and heavy snowfall. Low-density snow was easily transported onto Northerly facing slopes. Drifts 1'-3' we found on each aspect but we most concerning on any northerly facing slope.
Snow Characteristics
New Snow Depth
8"
New Snow Density
Low
Snow Surface Conditions
Powder
Snow Characteristics Comments
Low-density snow made for bottom-feeding conditions on south aspect. Would not recommend south-facing little cottonwood canyon slopes tomorrow unless thin & rocky is your thing.
Red Flags
Red Flags
Recent Avalanches
Heavy Snowfall
Wind Loading
Cracking
Poor Snowpack Structure
Red Flags Comments
Large shooting cracks were widespread on northerly facing slopes today along the cottonwood ridgeline.
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Same
Problem #1 Comments
Strong southerly winds were drifting the low-density snow onto the northern half of the compass and creating sensitive wind slabs 1'-2' deep. These slabs were hard and stiff in the most exposed terrain and significantly softer and less cohesive just a few hundred feet off the ridges Large shooting cracks were an obvious indicator you were in the sensitive slab areas, These slabs were not hair-trigger but easy to provoke an avalanche with some kicking and stomping in the right spots.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #2 Comments
The snow since Monday had not created a cohesive enough slab to bring the buried facets s to life..yet. It's not a matter of if, but when those layers will fail. The wind will certainly help to stiffen things up and help to create a more bonded slab over the weak layer that is now buried 8"-16" below the new snow. The crust layer will complicate things further and allow a greater load before the weak layer roars to life. I found the crust layer to be very thin (roughly 1c m) and very fragile today.
Snow Profile
Aspect
North
Elevation
9,500'
Slope Angle
34°
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
High