Sawtooth Avalanche Center

Public Field Report

Observation Details

Observation Date:
December 13, 2019
Submitted:
December 15, 2019
Zone or Region:
Galena Summit and Eastern Mtns
Activity:
Skiing/Snowboarding
Location:
'Tweener' Ridge - NE aspect, 8900'

Signs of Unstable Snow

Did you see shooting cracks? 
Yes, Widespread
Did you experience collapsing or whumpfing? 
Yes, Widespread

Observations

We traveled on very low angle terrain with no overhead hazard. We ascended NE, poked over to E. We noticed slightly increased wind compaction under the skiff of fluffy new once we were up on the broad ridge.

Media

snow profile location
surface hoar - from highly visible layer, buried about 50 cm below the surface

Advanced Observations

Observed Avalanche Problem #1: 
Persistent Slab
Comments: 
We experienced extensive collapses and shooting cracks in the low angle NE and SE aspects on the ridge. A test profile at 8900 feet in 80 cm deep snow showed 6 mm surface hoar buried 50 cm below the surface. We found an additional surface hoar/facet layer 15 cm below the surface. A single compression test showed CTE SC down 15cm on the facets (buried in this recent storm Dec 12th) and CTM SC down 66 cm in the basal facets just above the ground. We followed with an ECT and got ECTP 22, down 50 cm, on the 6 mm surface hoar.