Pro Field Report

Basic Information

Observation Details

Observation Date:
January 22, 2023
Submitted:
January 23, 2023
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Burn above Smiley Creek (7,300-9,200', primarily W-NW-N-NE-E)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
Avalanches observed refers to wet loose slides.

Snow Stability

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

Advanced Information

Weather Summary

Cloud Cover:
Mostly Sunny
New/Recent Snowfall:
2-3cm at highway

Afternoon wx obs: some mid level clouds hanging on to the tops of the Boulders, Smokys, and Sawtooths on my drive north. Wind transport evident along the highway corridor and flagging observed on exposed ridgelines. Cold temperatures all day. Steady moderate winds blowing out of the NE during my tour, transporting the 2-3cm of HN and some FCsf.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
4 Jan 20, 2023
(+/- 3 days) 		Grand Prize Canyon
S 9000ft 		D1.5 N-Natural
Set of what appear to be wet loose avalanches, but can't be certain from this angle.
Report
Grand Prize Canyon

I saw a lot of small wet loose with the naked eye while driving, I think a lot of this may have happened on Saturday (1/21) but I'm not certain

Snowpack Observations

Mostly a leg stretcher, but I dug in 3 locations to look at 1/5 and mid-December weak layers. I found small 2-5mm standing SH at 1/5 in all three pits, underneath a 35cm thick, faceting slab. I did not get any propagating results in ECTs (ECTNs in the 14-19 range x 9), but the SH was standing up with air space in between crystals in all pits and blocks sheared off cleanly. I suspect with some wind loading or additional snowfall this would still make avalanches where it looks like this.

December weak layers (12/19 and 12/26) looked ugly, with facets on either side of sun and wet snow crusts, but these produced ECTNs with extra hard force (ECTN 40-45) in my pits and rough shears.

I only isolated 11/27 in one of my pits and got an ECTP 35 (5 extra hits from the shoulder), down 80-90cm.

There is a thin crust on all aspects up to around 8000', down 10cm. I think this formed from ambient warm, wet air on 1/13, based on my observations of a similar layer further north in the valley. On top of this crust are some 2-4mm standing SH grains, and there are some small, 1mm FCsf below. There is not a slab on top of this yet, but this layer could be problematic with more loading.

Avalanche Problems

Persistent slabs (1/5, 12/26, 12/19, 11/27) all on my problem list here. Wind slab was on my list but I did not encounter a wind slab problem where I was, though I'm sure you could've found one given the amount of obvious blowing snow.

Terrain Use

Continuing to avoid large, consequential avalanche terrain, but feeling comfortable nibbling at the margins (planar and supported slopes out of obvious wind loading).