Sawtooth Avalanche Center

Pro Field Report

Basic Information

Observation Details

Observation Date:
January 11, 2021 - January 12, 2021
Submitted:
January 12, 2021
Observer:
SAC - Chris Lundy (off duty)
Zone or Region:
Banner Summit
Location:
Elk Creek Guard Station (6400-8400, E-S-W)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
Saw one recent, D1.5 loose snow avalanche originating from steep, rocky solar terrain - likely sun-induced dry loose from 1/9.

Snow Stability

Stability Rating: 
Fair
Confidence in Rating: 
Moderate
Stability Trend: 
Worsening

Bottom Line

Snowpack in this area is similar to other areas of the Banner Summit zone, perhaps a bit thinner overall in depth. Weak layer is buried 2.5' deep in mid-elevation terrain.

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Wind:
Light , W
New/Recent Snowfall:
Snowfall began around 9am this morning. 7cm HN when returned to our car at 1300.

1/11: Some scattered high clouds, but nice day with plenty of sunshine. Light winds. Temps remained cool.
1/12: Snowfall began around 9am. S1 for most of the morning, turning to S2 in early afternoon.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
1 Jan 5, 2021
(+/- 3 days)
Steep/rocky solar terrain above Cape Horn rd
S 7800ft
D2 SS-Soft Slab O-Old Snow N-Natural Report
Steep/rocky solar terrain above Cape Horn rd

Also, the loose snow avalanche listed above.

Snowpack Observations

Been trying to gauge snowfall patterns in the Banner Summit zone and am starting to think that the Copper Mtn area is slightly wetter than some of the other portions of this zone. However the difference is subtle, and the snowpack in this area was nearly identical in structure to areas closer to HWY 21.

HS at 6400' was 90cm, ranging to 125cm at 8000'. Slab depth range from about 2 to 2.5'. We never got very high (<8300') or very shady (E was the shadiest).

@7700', E: HS 125cm. 75-80cm slab over 12/11. Slab hardness at base was 1F+, approaching P. Weak layer hardness was 4F-. The weak layer is finally showing some signs of getting squashed but it's got a ways to go. ECTX but ECTP with a couple hard hits.

SH was fairly widespread on shady and sheltered slopes, although it seemed relatively small and not of the typical "structure" that tends to form buried weak layers. But - another thing to keep in mind with the incoming storm.

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Deep Persistent Slab
Isolated
Specific
Widespread
Unreactive
Stubborn
Reactive
Touchy
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
Layer Depth/Date: 60-80cm
Weak Layer(s): Dec 11, 2020 (FCsf)
Comments: Rose indicates observed terrain. 12/11 is still easily felt with a ski pole.