Pro Field Report

Basic Information

Observation Details

Observation Date:
December 18, 2020
Submitted:
December 20, 2020
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Galena Summit and Eastern Mtns
Location:
Butterfield (6,700-9,700', mostly SE-E-NE-N)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
Isolated

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Moderate
Stability Trend: 
Steady

Media/Attachments

Snowpack at 9,100' on E aspect of Butterfield.
Snowpack at 9,100' on E aspect of Butterfield.

Advanced Information

Snowpack Observations

Quick rec tour. HS=65-75cm on E at 8,000'. New snow "slab" is mostly F- here with a F interval at the base (snow from 12/13). Total slab thickness is 18-20cm. PST and CPST returning slab fracture results in the upper single-digit range (7-9/100cm). ECTN 2. Feels like we are lacking enough of a slab to make things happen here, but just barely.

On solars, where MFcr exists below new snow informal tests revealed a less reactive interface than I observed the previous day in Sawtooths. My hunch would be that the solar problem is worse in areas that received snow on both 12/11 and 12/13 (essentially Galena pass area and north). In these areas, snow faceted on 12/12 and 12/14.

Continuing to monitor base of snowpack in areas that did not have pre-11/7 snow. Larger grained facets (2-3mm) developing in these areas in bottom 5cm of snowpack. Suspect you'd need a pretty smooth slope to have a problem at the ground, but could see things stepping/gouging down as we start to see more of a slab building on top of the snowpack.