Pro Field Report

Basic Information

Observation Details

Observation Date:
March 7, 2021
Submitted:
March 8, 2021
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Fishhook to Profile (6,300-9,800, S-SE-E-NE-N)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced
Avalanches observed refers to small, intentionaly triggered slabs and fresh debris below cliff bands. Cracking experienced in fresh wind slabs.

Bottom Line

Primarily concerned with new snow issues, but still have lingering concerns about persistent slab problems in large, open terrain at upper elevation, particularly on slopes that face the sun.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Wind:
Moderate , SW
New/Recent Snowfall:
Trace of snow at the Ranger Station, 2-3cm at the top of the morraine, up to ~10cm in the alpine (?) - hard to be certain due to amount of wind affect. Ski tracks from the past few days were totally obscured.

Cloud cover increasing from clear in the morning to BKN/OVC in the mountains in the afternoon. A few S-1 flurries in the afternoon with no accumulation. Varaible winds blowing light to moderate with occasional, brief strong periods. Tough to get a precise sense on direction.

Avalanche Observations

Intentionaly triggered several D1s in very steep terrain. Slabs were small but they entrained a good amount of debris due to the terrain. Also observed a number of fresh D1 piles beneath cliff bands, these must have run overnight sometime.

Snowpack Observations

Fresh slabs were thin, but touchy. Encountered slabs up to 20-25 cm thick that were reactive to the weight of a skier on both solar and shaded aspects. These slabs were fairly disconnected but could become more problematic with another shot of new snow and wind tomorrow. Wind was blowing moderate with periods of strong gusts, continuing to build slabs until my exit from the field at 1700. Low elevation and sheltered middle elevation slopes facing the sun melted a bit, upper elevations stayed cold.

Upper elevation solars were holding a ski and boot supportable crust underneath the new snow throughout the day. Overlying snow is poorly bonded to this crust. At middle elevations, the underlying snow had not refrozen well, and boot pen was quite deep if you got through the crust. Lower elevations had a ski supportable crust in the morning but had softened to isothermal mush by the end of the day. Shaded slopes at middle and upper elevations have recently buried facets underneath the new snow, but snowpack is generally strong underneath these. At lower elevations there wasn't enough new snow to get a good sense for how well bonded the new snow was.

Avalanche Problems

Was primarily concerned with new snow issues: small, isolated wind slabs in very steep terrain and dry loose sluffing. Persistent slab problems are still affecting my travel in this area, particularly in big, open terrain on solars.

Terrain Use

Felt comfortable entering steep, confined terrain while paying close attention to new snow issues.