Observation: Greens Basin

Observation Date
Observer Name
Salt Lake » Big Cottonwood Canyon » Greens Basin
Location Name or Route
Greens Basin via Days
Light Snowfall
Wind Direction
Wind Speed
Weather Comments
Overall, it was an overcast day in the mountains, with brief periods of sun in the morning that gradually transitioned into a persistent overcast sky, accompanied by light snowfall by the afternoon. While we primarily traveled at lower and mid-elevations, the winds remained moderate among the trees, but noticeably stronger along the ridgetops, where active transport was evident.
Snow Characteristics
Snow Surface Conditions
Faceted Loose
Wind Crust
Melt-Freeze Crust
Snow Characteristics Comments
Huge variety in snow surfaces today. The warm temperatures have really affected most aspects. At lower elevations, all aspects were damp. As we gained elevation, the more westerly aspects remained damp, while the easterly aspects developed a 2mm melt-freeze crust on top. The only aspect retaining cold snow was true north. Along ridgelines, obvious texture was evident due to the elevated winds over the last 24 hours.
Images of the melt freeze crust on easterly aspects.
Avalanche Problem #1
Wet Snow
Decreasing Danger
Problem #1 Comments
While the overall issue I would be avoiding today would be the slabs of wind-drifted snow, the primary concern we encountered was honestly the wet snow. The temperatures were very warm, reaching 58 degrees at the base of Big Cottonwood Canyon, and although they did begin to drop throughout the tour, the wet snow remained problematic, even off only south aspects. West-facing aspects were warming up, leading to widespread roller-balling and pinwheeling. This phenomenon was widespread throughout the trees, necessitating management similar to that of sluff management. While this may not become a significant issue moving into the next storm, it was our main concern today and will result in a wide variety of snow surfaces for the new snow to fall onto, as well as large frozen pinwheels and roller balls hidden under a few inches of snow.
Avalanche Problem #2
Persistent Weak Layer
Problem #2 Comments
The primary goal today was to examine the mid-elevation east-facing aspects and observe the healing process of the melt-freeze facet crust interface. However, everywhere we dug ended up having more of an ENE or NE aspect, making it difficult to find the melt-freeze crust intact. While we did locate a very well defined interface, overall, it appeared thin and rounding. At 9070', we obtained an Extended Column Test (ECTX) result on an ENE aspect. Despite the limited exploration of eastern aspects at mid-elevations, another day of warm temperatures will likely continue to improve the situation regarding this persistent weak layer interface.
In our travels, I wasn't able to find any of the widespread surface hoar or near-surface faceting that I encountered during my last field day. Considering that most of the snow surfaces were damp or had a generally damp crust, I would speculate that the next system, arriving as a southwest flow, will bond well to this variety of surfaces.
Today's Observed Danger Rating
Tomorrows Estimated Danger Rating