Pro Field Report

Basic Information

Observation Details

Observation Date:
December 10, 2020
Submitted:
December 11, 2020
Observer:
SAC - Davis, VandenBos
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Frenchman Creek (Primarily W-N, 7,000-9,500')

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Snow Stability

Stability Rating: 
Very Good
Confidence in Rating: 
High
Stability Trend: 
Steady

Bottom Line

We would have been hesitant to step out into some terrain where weak snow was found at the ground, namely steep, alpine, north-facing slopes. Beyond that, there were no avalanche concerns.

Surface hoar was found health and intact on exposed 9,500' ridge. It was likely buried (last night) or will be buried in decent shape.

Media/Attachments

Large surface hoar crystals near the valley bottom of Frenchman Creek. Smaller versions of these crystals were found on exposed ridgelines as high as 9,500'.

Advanced Information

Weather Summary

Cloud Cover:
Clear
Temperature:
Inverted
Wind:
Calm

Clear, calm and cool. Inversion held strong through the day with valley floor temperatures considerably colder than at pass level.

Snowpack Observations

We dug two pits on W-NW facing slopes at 8,400' and 9,500'. There were no notable test results.

October facets were found at the upper pit location but not the lower. However we suspect they may have been present on more of a due north?

The upper ~20-30 cm of the snowpack was weak in both locations. This weak layer was thicker at lower elevations.

Surface hoar was present on most shaded slopes including an exposed ridge at 9,500'

Terrain Use

As noted above, we would have been hesitant to step out into some terrain where weak snow was found at the ground, namely steep, alpine, north-facing slopes.