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Observation: Upper Weber Canyon

Observation Date
2/4/2021
Observer Name
jg
Region
Uintas » Upper Weber Canyon
Location Name or Route
Upper Weber
Weather
Sky
Broken
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Light
Weather Comments
Cloudy most of the day with periods of brief clearing. On and off snowfall throughout the day. Light to moderate winds from the NW. Temps in the teens and single digits.
Snow Characteristics
New Snow Depth
10"
New Snow Density
Medium
Snow Surface Conditions
Powder
Snow Characteristics Comments
Rightside up storm snow. Very low density snow on top of increasingly dense fist hard snow.
Red Flags
Red Flags
Collapsing
Poor Snowpack Structure
Red Flags Comments
The snowpack was quiet most of the day with no cracking and only one collapse.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Same
Problem #1 Comments
There are multiple PWLs in the snowpack where I was. The deeper PWL is very worrisome, especially as we start adding more weight to the pack and the slab becomes more cohesive and connected.
Avalanche Problem #2
Problem
New Snow
Trend
Same
Problem #2 Comments
The new snow did not bond well to the old snow surface. I got clean shears with shovel shear tests and CTs but that layer never propagated across an extended column. Possible that it settles out with time.
Snow Profile
Aspect
Northwest
Elevation
9,300'
Slope Angle
28°
Comments
Between 8K and 9500 ft. snow totals were 3-4 feet. Not much of a slab down at lower elevations and very unsupportable on a sled and, at times, on skis. Boot penetration to the ground at all elevations traveled. I noticed a fair amount a spacial variability in the thickness and density of the slab sitting on the weak basal snow.
I had finished digging my snowpit and had a clean pit wall prepared when my partner stepped off his board and collapsed a large piece of snow with a very loud whoopf. I was looking at the pit wall when this happened and watched the slab collapse on the deeper persistent weak layer.
I really don't see this layer getting better anytime in the near future. Avalanches are just going to get more unpredictable and larger as we add more weight to the snowpack. I'll keep playing the slope angle game and continue to keep slope angles below 30° and be conscious of what's above or connected to me when I'm traveling.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates