Pro Field Report

Basic Information

Observation Details

Observation Date:
February 10, 2020
Submitted:
February 11, 2020
Observer:
SAC - VandenBos, Lundy (off duty)
Zone or Region:
Sawtooth and Western Smoky Mtns
Location:
Valley Creek Drainage, north of Stanley

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
Observed slide on Copper Mountain, hard to be certain on timing. Only other observed avalanche was previously reported slide on Cabin Creek Peak

Snow Stability

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

Advanced Information

Weather Summary

Partly to mostly cloudy in the morning with skies clearing into the early afternoon hours and staying that way until sunset. Temperatures remained cool despite incoming solar radiation. Winds were calm to light out of the north. Tough to get a great handle on amount of snow from previous storm but estimated at settled 30-35cm with an additional 15-20cm underneath from 2/2 precip.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Comments Photo
1
Relatively recent slide on E-SE aspect of Copper Mountain at 8,700'. Based on appearance, location, and time of year, it wouldn't be surprising to hear that it failed on near surface facets. In moderately wind loaded terrain.
This avalanche on Copper Mountain was observed on 2/10 and appears to have failed relatively recently. It failed on an E-SE facing slope at 8,700'.
1 Cabin Creek Peak
SW 9,000' 		Failed in heavily wind loaded terrain, estimated to have failed sometime during the storm between 2/5 and 2/8 when winds were blowing from northerly direction.
This avalanche on Cabin Creek Peak, northeast of Stanley, appears to have failed sometime during the previous round of storms (2/5-2/8). It failed on a S-SW facing slope at 9,000'.

Avalanche on solar aspect of Copper coincides with prime time near surface facet season. This is the only avalanche of this variety that has been reported, but could be an indicator of a more widespread unstable interface.

Snowpack Observations

at 7,800', HS =120-135cm on W, 130-145 on E. At 8,600' HS =140-170 cm. More shaded aspects were holding upwards of 200cm of snow, but at least some of this appeared to have been a result of wind drifting. Informal snowpack tests revealed no obvious instabilities in the upper snowpack. Basal FC/DH present based on probing, but no formal stability tests performed.

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
Deep Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5