Observation: South Mountain

Observation Date
1/14/2021
Observer Name
Chris Benson
Region
Moab » South Mountain
Location Name or Route
NE Bowl South Mtn
Weather
Sky
Clear
Wind Direction
Northeast
Wind Speed
Moderate
Weather Comments
Wind gusted up to ~30 mph at times. Not much snow available to transport, but my skin track was filled-in after about 2 hours.
Snow Characteristics
Snow Surface Conditions
Dense Loose
Snow Characteristics Comments
Snow depth ranged from about 30 cm to 80 cm. In the trees on northerly aspects, this snow was fairly supportive and almost sort of creamy. Imagine making cream cheese out of facets. It was sort of like that....
Above treeline, snow was pretty wind-hammered and displayed a range of textures from punchy-shallow-facets to bullet-hard wind slabs, and some soul-searching sastrugi inbetween.
Red Flags
Red Flags
Cracking
Collapsing
Red Flags Comments
Observed many localized collapses today, mostly while below treeline in meadows on low-angle northerly slopes. Shooting cracks up to around 20' were present in a few of these collapses.
Avalanche Problem #1
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #1 Comments
There is obviously a poor snowpack structure throughout the entire range. Facets on one or two crusts seem to be the most problematic. Interestingly, I did note some large sized (1-2 mm) facets near the top of the snowpack- which is a little weird... but so is 2021, C'EST LA VIE! These could be some near-surface facets, but it was strange to see such large grains near the top of the snowpack. This area is very wind-affected, and contained some denser wind-deposited layers overlying these problematic weak layers. Snowpack temps were fairly warm- sort of surprising, but the steep temperature gradient in the top 10-20 cm suggests that we may be forming some near-surface facets during this January drought.
Two compression tests yielded moderate results with sudden-collapse fracture character on facets above the basal crust.
Avalanche Problem #2
Problem
Wind Drifted Snow
Trend
Same
Problem #2 Comments
There isn't much of a slab across the range, except where wind has deposited dense snow. I didn't observe snow transport at ridgetop, however, what little snow that was available for transport seemed to fill-in the skin track as well as my snowpit. Snow depth was quite variable, with some slopes in the alpine completely stripped bare of snow (NW aspect off of South Mtn.)
Snow Profile
Aspect
Northeast
Elevation
10,500'
Slope Angle
22°
Comments
My guess is this is exactly where you can trigger an avalanche right now. Steep, northerly slope that has a wind slab sitting on top of various weak layers. I noted some debris and a fuzzy crown line in this terrain, and these may be from the late December storm.
Many southerly slopes in the alpine are complete devoid of snow. Avalanche danger changes dramatically with changes in aspect.
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Coordinates