Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
December 9, 2020
Submitted:
December 9, 2020
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Soldier and Wood River Valley Mtns
Location:
Morgan Ridge (6,000-8,500', primarily S-SW-W-NW-N)

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

SE-S-SW-W slopes are dry. Other slopes are holding a thin, variable snowpack made up of wind drifts, various crusts, and facets.

Media/Attachments

Snow coverage in the mountains near Ketchum and Sun Valley. Looking NW from the top of Morgan Ridge.
Looking E from the top of Morgan Ridge

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
Wind:
Calm

Weak inversion persisting into the afternoon.

Snowpack Observations

Snow distribution is primarily driven by aspect and secondarily by past winds. Lower and middle elevation slopes from SE-S-SW-W are dry. HS=15-30cm on shaded slopes not affected by wind, lots of sage brush sticking through in these areas still. I encountered old, icy/slick drifts up to 60cm thick along ridgelines. Many of these were quite stiff, including some which were elk-supportable. Despite the lack of snow, the snowpack is much less faceted than I've been finding in northern areas, likely thanks to the weaker inversion and significantly warmer overnight temperatures. Even at valley bottom the 10-20cm of snow is quite ski supportable. Shaded slopes I encountered are holding a mish mash of crusts and facets, but not the sand-castle style snowpack that I've seen up north and have seen develop in pervious years in WRV. Of course, that is specific to where I was, not sure how things are looking in other WRV areas. Morgan can be a pretty windy place, particularly when northerly winds (like those at the end November/beginning December) are blowing down the valley. I suspect that more sheltered shaded slopes are pretty faceted.

Avalanche Problems

No avalanche problems encountered.

Terrain Use

Avoiding bare ground was the only concern where I traveled.