Pro Field Report

Basic Information

Observation Details

Observation Date:
March 21, 2021
Submitted:
March 22, 2021
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Fishhook/Profile (6,500-10,600', SW-S-SE-E-NE-N)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
Moderate
Stability Trend: 

Bottom Line

Lots of storm snow issues during the storm, but new snow was generally bonding well to the surfaces it fell on. Small wind slabs and loose snow avalanches could ruin your day if you encountered them in the wrong terrain.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny

Day dawned clear and stayed that way for a few hours. Cumulus built in the late morning hours, hanging low over the range and reducing direct solar input. Clouds lifted in the afternoon, providing 1-2 hours of very light convective showers with no accumulation. Winds were generally calm, with a few outlier burst of moderate, cold wind from the SW. Clouds aloft were moving out of the NE. Hard to get a great sense of HST, out on the moraine most precip had fallen as rain with just 1-2cm of dry snow. Along the range front I was finding between 8-12cm of snow that had fallen in two pulses, one wet and one much drier. Deeper in the range at at upper elevations there wasn't a significant difference in density, just ~15-20cm of 6-8% snowfall.

Avalanche Observations

Lots of smal,l storm snow avalanches occurred during the storm. Precipitation intensity must have been pretty high at points during the storm, accounting for this activity. There was a concentrated amount of loose activity around 7,800-8,000', which seemed like about the top of the rain line. I did not observe any slides that appeared to be D2 in size. I did observe one small mid-slope slab that may have occurred naturally today. A small solar initiated loose snow slide flanked out about 30-40' wide on a mid-slope roll. I was also able to trigger some D1 loose snow slides in both solar and shaded terrain. These were small and predictable, but plenty large to ruin your day if you were caught in the wrong terrain.

Snowpack Observations

New snow had generally bonded well to the surfaces it fell on. Morning sun generated a few loose snow slides in steep terrain, but cloud cover put a pause on this process. I could see wet loose becoming a problem during the next day of full sunshine. At lower elevations, ambient temperatures and sun were enough to begin to break down the crust that formed, providing isothermal conditions.

Avalanche Problems

I encountered very small, unreactive wind drifts and areas where loose snow issues were worth keeping in mind but nothing that I would describe as a problem.