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Observation: West Porter

Observation Date
12/18/2019
Observer Name
Greg Gagne
Region
Salt Lake » Mill Creek Canyon » Porter Fork » West Porter
Location Name or Route
West Porter to Main Porter
Weather
Sky
Few
Weather Comments
Temperature inversion with warmer temps at the upper elevations. Windless.
Snow Characteristics
Snow Surface Conditions
Faceted Loose
Damp
Snow Characteristics Comments
HS in Porter above ~8000 > 1 meter. Snow surface was crusted or damp on solar aspects (which fortunately are limited near the solstice) with facets and surface hoar at the surface. Some SH feathers are up to 5-8 mm in size (photo below). The weak snow surface will be something to watch going forward once we get a new load or snow (or wind) on top.
Red Flags
Red Flags
Poor Snowpack Structure
Red Flags Comments
Facets near the ground are showing signs of gaining strength.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #1 Comments
Weak facets in the bottom 20-25 cms of the snowpack on northerly aspects at the mid and upper elevations. The slab on top of the facets is gaining strength, and pencil-hard in many places. The facets near the ground < 9000' are rounding and sintering (gaining strength), and damp. ECTN30 down near the ground at 8700'
Will call this problem slowly decreasing danger.
Snow Profile
Aspect
North
Elevation
8,700'
Comments
Overall am gaining confidence in the snowpack adjusting to the load, and today's pit at the mid elevations shows the facets down near the ground gaining strength with evidence of sintering and rounding. Although I did not get higher than ~9500', I also imagine at the upper elevations the facets remain weaker than at the mid elevations.
I remain skeptical of the stability of steep, upper elevation aspects, especially those that have already slid ("repeaters") where the snowpack may be thinner and avalanching may be easier to instigate.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate