Pro Field Report

Basic Information

Observation Date:

December 20, 2019

Submitted:

December 21, 2019

Observer:

SAC - VandenBos (off duty)

Zone or Region:

Galena Summit and Eastern Mtns

Location:

Galena Peak

Recent Avalanches?

Yes

Cracking?

Isolated

Collapsing?

Isolated

Avalanches observed and cracking refer to very small, fresh wind slabs along ridgeline above 10,000'. Isolated collapsing on 12/7 SH further down the ridge, between ~8,200 and 9,800'

Stability Rating:

Fair

Confidence in Rating:

Moderate

Stability Trend:

Steady

Advanced Information

Temperature:

low 30's at highway, low 20's (est) on top

Wind:

Moderate , SW

Evening wx obs. Storm total, 2-3 cm. Skies clearing as the sunset, lots of stars around with low, scrappy clouds hanging down low, occasionally being pushed up and over the peaks. Wet, SW wind blowing pretty steady moderate above 10,000', steady at the upper end of moderate/low end of strong above 11,000', building some nice rime on rocks, grasses and me.

#	Date	Location	Size	Type	Bed Sfc	Depth	Trigger	Comments	Photo
2		Galena Peak N 10,500'	D1	SS	I-New/Old Interface	10cm	AS-Skier c-Intentional	Light jumping on small wind pillows released two very small wind slabs along ridgeline. Each 5-10m wide, 10cm thick, ran downslope ~30-40m. Due to the small amount of new snow, these appeared to be the only spots where loading conditions were sufficient to build slabs. Slabs failed on slick, wind-buffed alpine surface.
0									None

Problem	Location	Distribution	Sensitivity	Size	Comments
Persistent Slab	N E S W	Isolated Specific Widespread	Unknown		Layer Depth/Date: 12/7 SH, down 30cm Comments: Still producing cracking and collapsing
Wind Slab	N E S W	Isolated Specific Widespread	Unreactive Stubborn Reactive Touchy	D1 D1.5 D2 D2.5 D3 D3.5 D4 D4.5 D5	Comments: Not really a problem, thanks to lack of snow - slabs were very small and isolated.