Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
March 8, 2020
Submitted:
March 9, 2020
Observer:
SAC - VandenBos (off duty)
Zone or Region:
Galena Summit and Eastern Mtns
Location:
North Fork Big Wood

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
Isolated
Collapsing? 
None Experienced

Snow Stability

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

Bottom Line

A few inches of new snow improved skiing conditions and gave the wind some ammunition for isolated wind slabs in exposed upper elevation terrain.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Wind:
Light , W

HST=6-7cm at upper elevations, trace at highway level. Day dawned mostly clear, then cloud cover increased to mostly cloudy to broken. Calm in the morning with wind speeds picking up in the afternoon hours, blowing out of the west at light to moderate speeds. Occasional periods of S-1 flurries with no accumulation.

Snowpack Observations

At lower elevations, snowpack surface was frozen 10-15cm deep with another 10-15cm of moist snow below. Ambient radiation and mild temperatures down low allowed for crust to gently break down by late afternoon. Above about 7,000', freeze was more substantial and snow below crust was dry. Encountered a number of isolated,15-20cm wind slabs on a variety of surfaces, which were unreactive. With the right combination of slab and bed surface I could see triggering a small, fresh wind slab, and I traveled accordingly. Periods of sun and clouds helped the new snow bake onto the old surface and solar aspects were skiing like fresh, cool to warm corn by mid day.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Wind Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5