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Observation: Twin Lakes Pass

Observation Date
12/7/2023
Observer Name
Gagne
Region
Salt Lake » Little Cottonwood Canyon » Grizzly Gulch » Twin Lakes Pass
Location Name or Route
Twin Lakes Pass
Weather
Sky
Obscured
Precipitation
Light Snowfall
Wind Direction
Northwest
Wind Speed
Moderate
Weather Comments
Gusty NW winds.
Snow Characteristics
New Snow Depth
2"
New Snow Density
Medium
Snow Surface Conditions
Powder
Wind Crust
Melt-Freeze Crust
Snow Characteristics Comments
5 cms of storm snow with graupel. Gusty winds were drifting some snow, but overall wind drifts were shallow (5-10 cms) and not sensitive. I imagine there could be a few isolated wind pockets that may be reactive in upper elevation terrain. South and west aspects are crusted from warm temperatures this past week.
The good news is that moderate to strong winds at the mid and upper elevations have eroded the weak layers of surface hoar, near-surface facets, and radiation recrystallization that formed on the old snow surface and Drew mentioned in his observation from PC ridgeline on Wednesday.
Red Flags
Red Flags
Recent Avalanches
Poor Snowpack Structure
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Increasing Danger
Problem #1 Comments
The PWL down near the ground is beginning to show some signs of strengthening in areas with a deeper snowpack in the upper elevations. A week ago the PWL in the bottom 10-30 cms of the snowpack was very weak and only Fist hard. I am now finding it moving to a stronger 4F hardness. Although it is gaining strength, we still have the poor structure of strong snow over weak snow, with a strong 1F slab on top of weaker 4F facets.
In two pits on northerly aspects - one at 9K and another at 10K, I was still getting full propagation in the mid 20's with ECT tests, indicating the PWL is becoming harder to trigger avalanches on, but it remains a concern.
With more snow and wind on the way, we are placing an additional on the PWL layer.
Snow Profile
Aspect
North
Elevation
9,500'
Comments
Although I am seeing positive signs with the PWL gaining strength, the strong-over-weak structure and full propagation with ECTs will keep me off of slopes steeper than 30° on aspects facing NW through E where the PWL is present. Fortunately, the existing snowpack is supportable and there will be safer riding options on other aspects with new snow forecast beginning on Friday.
Photos of some wind loading and a break in the clouds. Also including a heat map of avalanche activity over the past week.
Today's Observed Danger Rating
Considerable
Tomorrows Estimated Danger Rating
Considerable
Coordinates