Pro Field Report

Basic Information

Observation Details

Observation Date:
December 8, 2020
Submitted:
December 9, 2020
Observer:
Pro
Zone or Region:
Banner Summit
Location:
Banner Summit and Copper (6,900'-9,000' N-SW aspects)

Signs of Unstable Snow

Recent Avalanches? 
None Observed
Cracking? 
None Experienced
Collapsing? 
None Experienced

Snow Stability

Stability Rating: 
Good
Confidence in Rating: 
Stability Trend: 

Bottom Line

The entire snowpack seems to have every problem in the book; likely the next loading event will produce a large cycle, but my concerns remain in the glades that may not avalanche naturally but might tempt skiers and harbor patchy and unpredictable SH (found in up to 8000' on N and some W aspects).

Media/Attachments

Advanced Information

Weather Summary

Cloud Cover:
Partly Cloudy
Wind:
Calm

Clear, sunny skies in the AM lead to mid-morning scattered skies. The later afternoon cleared; calm winds and warm temps.

Avalanche Observations

Noted no recent avalanche activity in this area or in viewable paths along Lowman. Peaking towards the N off of the first Copper summit, wouldn't be surprised if smaller pockets of hard wind slab were presently unstable; it appeared people had skied to the N.

Snowpack Observations

Pit dug at Banner SNOTEL; extensive faceting throughout the pack with more mature facets present above and below melt-freeze and rain crusts from mid November dry spells. New SH growth along with buried SH down 6cm (ECTN2); SH preserved in skiable glades and low angle terrain surrounding standard W ridge approach up Copper.

Rain crust still apparent up to ~8000' (ECTN22 down 30cm). Due solar aspects cooked and warmer temps/lack of wind made for punchy unsupportable skiing. Upper terrain of N summit nearly bare with exposed rock and sage. Best skiing was found on N aspects in trees untouched by sun, and conversely in the upper elevation S aspects on compacted wind slab with no underlying weaknesses that skied supportably and softly due to warmer temps. Further S summit skied better and has maintained better coverage!

Terrain Use

Avoided terrain where any recent weather might have caused slab formation atop older snow, either via warming temps or via wind on upper elevation, cooler aspects.