Observation: Moab

Observation Date
12/15/2019
Observer Name
Chris Benson, Steve Evers, Courtney Kizer
Region
Moab
Location Name or Route
La Sal Pass
Avalanche Problem #1
Problem
Wind Drifted Snow
Trend
Same
Problem #1 Comments
Near treeline, abundant wind transport has taken place with W and SW winds stripping snow from windward and ridge top locations to E aspects. Snow depths were variable, with bare ground in spots near ridge line and 130cm-deep wind deposited pillows, just below ridge top. A 4-10 cm wind slab failed easily in shovel tilt tests on a buried graupel layer from the 12/8/19 thundersnow. Hard to say when this wind effect took place, but wind data from 12/14 shows wind gusts from the SW at times were 20 m/s. We did not see any blowing snow, and winds were quite calm in this area during our tour.
Avalanche Problem #2
Problem
Persistent Weak Layer
Trend
Decreasing Danger
Problem #2 Comments
At the base of the snowpack, 10 cm of ~1mm facets appeared to be rounding and gaining strength. These grains are what is left of the snow that fell on 11/19 and 11/20- the first appreciable snow accumulation to stick around. As it was warm today, these facets almost appeared moist, and were quite different from the typical mid-December, dry, cohesionless, and weak snow.
Snow Profile
Aspect
East
Elevation
11,100'
Comments
Overall, the snowpack seems to be fairly cohesive. No cracking or collapsing was noted on todays tour. Shallow to moderately deep wind slabs probably exist on E, NE, and SE aspects. A buried graupel layer is a weak layer, but will gain strength with time. Most of the snowpack is a strong, bonded, and dense slab of snow- with the important exception of a few interfaces. We found one about 32 cm down that almost appeared as buried graupel, or maybe even buried surface hoar, but this pit location would be pretty unlikely to preserve surface hoar. This interface/ thin weak layer did not produce propagation results across the block with an extended column test (ECT) (ECTN25 RP).
The depth of snow elsewhere in the La Sal Pass area seemed to average around 50 cm. South Mountain Glades looked a little thin, perhaps to thin to enjoy.
Although the snow is thin in spots, it is fairly supportive, and overall, it feels a bit more maritime than our typical early-season, continental snowpack.
Video
Today's Observed Danger Rating
Moderate
Tomorrows Estimated Danger Rating
Moderate
Coordinates