Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
February 17, 2020
Submitted:
February 17, 2020
Observer:
SAC - Stefan, Johnson
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Frenchman drainage

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
Isolated
Collapsing? 
None Experienced
Stomped a few fresh cornices but dit not any cracking to speak of and could not trigger any fresh slabs either. Isolated cracking in fresh, 2" thin wind skin on N-NW facing high elevation terrain.

Snow Stability

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

Bottom Line

About 10cm of new snow in this area, still unconsolidated for the most part.
Thin, very isolated wind slabs on NW facing terrain, and wind slabs on E-SE were not reactive. Quite poor structure on solar terrain, but in the absence of a slab it is for the moment not a concern.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Temperature:
cool
Wind:
Calm , NW

We were right on the edge of the storm, north of Smiley creek was mostly socked in and we had a mixed bag of sun and clouds, with a few squalls of mod NW winds and S-1 to S1 snow but no accumulation to speak of. Solars remained cool all day.

Snowpack Observations

HN around 10cm, maybe 15cm at higher elev sheltered terrain if we are generous.

Surprisingly low HS at low elevs, 50-80cm in N facing sheltered terrain. All of it in some state of faceting, with previous slab deteriorating to the point of trapdooring in places.

SE-ESE mid to high elevation have a nasty 2-5cm MFcr - 10cm FCsf on RG 4F+ windslab combo below the 10cm of PP. Could be interesting if we actually got a load on it.

Most new snow still unconsolidated, very isolated slabs along ridge lines but unreactive to ski cutting and cornice drops. Very low HS in many areas that should be loaded or sheltered from recent wind, mid elevation HS sub 1m and down to 50cm in some places. FC all the way to the groundin the thin spots, under 2-5cm MFcr on anything that gets sun. Weak structure but no slab in other words.

8500' NNE sheltered meadow HS 120cm
Right side up 110-45cm 4F-P+ slab
4F FC at 45cm on MFcr K hard gave no results on ECT
DH from 0-15cm mostly 1F hard with an interface at around 10cm of weaker, large and occasionally chained crystals. Too close to gnd to give conclusive result given undergrowth, logs and such, but DTs in low 20s and clean shears when we managed to hit it. Would require pretty special circumstances to find this layer continuous enough to be able to propagate over larger areas, let alone triggering it.



8500' NNE

Terrain Use

We felt good skiing SE-E-NE mid 30s terrain with no wind loading.