Pro Field Report

Basic Information

Observation Details

Observation Date:
December 13, 2022
Submitted:
December 13, 2022
Observer:
SAC - Scott Savage
Zone or Region:
Soldier and Wood River Valley Mtns
Location:
Hailey - East Fork/Greenhorn: driving observations (all aspects and elevations that were visible from roads)

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced
Driving and glassing/photo mission, so the cracking and collapsing should be N/A.

Bottom Line

I observed around 100 obvious recent avalanches. There were others that released earlier in the storm and were almost entirely obscured. Many of the slides were quite fresh, either from Sunday afternoon or Monday. The number of large avalanches releasing just above the valley floor is impressive and very unusual.

Advanced Information

Weather Summary

Cloud Cover:
Mostly Cloudy
Temperature:
Teens F
Wind:
Light
New/Recent Snowfall:
Trace in past 24 hours

Clear skies initially with low to mid-level clouds moving in and eventually overcast skies/socked in and obscured. Evidence of previous wind-loading during the storm. Lots of snow remains available for transport.

Avalanche Observations

 #  Date Location Size Type Bed Sfc Depth Trigger Photos Details
2 Dec 12, 2022
(+/- 1 day) 		Hyndman Ck
NW 7900ft 		D2 SS-Soft Slab O-Old Snow AS-Skier
r-Remote
Multiple slides in the Hyndman Ck drainage appeared to be triggered remotely by skiers who were wisely avoiding avalanche terrain. NW aspect near 7800'.
Report
2 Dec 11, 2022
(+/- 1 day) 		East Fork Big Wood River - "Minebender" chutes
NW 8200ft 		D3 U-Unknown O-Old Snow N-Natural
Two very large, D3 avalanches released in the East Fork of the Big Wood River drainage downstream of Triumph. The slides involved multiple starting zones and ran over 2000' vertical.
Report
6 Dec 12, 2022
(+/- 1 day) 		Finley Ck-Cove Ck (Pioneer Mtns)
W 9100ft 		D2 U-Unknown O-Old Snow N-Natural
Several natural slab avalanches in the Finley Ck drainage off of Cove Ck in the Pioneer Mtns (8900-9300', SW-W-NW)
Report
10 Dec 12, 2022
(+/- 1 day) 		Greenhorn Gulch
N 5900ft 		D2 SS-Soft Slab O-Old Snow 2.5ft N-Natural
Several slides released on N aspects just above the valley floor in Greenhorn Gulch, running into the creek.
Report
2 Dec 12, 2022
(+/- 1 day) 		Big Wood River - near Greenhorn Gulch
NE 6000ft 		D2 SS-Soft Slab O-Old Snow N-Natural
Natural slides near the mouth of Greenhorn Gulch (5900-6100', NE).
Report
1 Dec 12, 2022
(+/- 1 day) 		Croseus Gulch - Croy
N 5900ft 		D1.5 SS-Soft Slab O-Old Snow N-Natural
Smaller persistent slab avalanche in Croseus Gulch (5900' N-NE).
Report
1 Dec 12, 2022
(+/- 1 day) 		Croseus Gulch area
NW 6800ft 		D2 SS-Soft Slab O-Old Snow N-Natural
Natural avalanche near Croseus Gulch (Croy Canyon), 6800' N.
Report
4 Dec 12, 2022
(+/- 1 day) 		Colorado Gulch
N 7000ft 		D2 U-Unknown O-Old Snow N-Natural
Natural avalanches in Colorado Gulch.
Report
2 Dec 12, 2022
(+/- 1 day) 		Croy - Democrat Gulch
NE 5600ft 		D2 SS-Soft Slab O-Old Snow N-Natural
Natural avalanche in Democrat Gulch (NE-5600').
Report
Hyndman Ck
East Fork Big Wood River - "Minebender" chutes
Finley Ck-Cove Ck (Pioneer Mtns)
Greenhorn Gulch
Big Wood River - near Greenhorn Gulch
Croseus Gulch - Croy
Croseus Gulch area
Colorado Gulch
Croy - Democrat Gulch

Snowpack Observations

No direct observations other than roadside obs. Some SH (surface hoar) formed last night in valley bottoms (up to 5mm).

Avalanche Problems

Problem Location Distribution Sensitivity Size Comments
Persistent Slab
Isolated
Specific
Widespread
 Unknown
D1
D1.5
D2
D2.5
D3
D3.5
D4
D4.5
D5
 Layer Depth/Date: 50-120cm is best estimate of what I observed
Weak Layer(s): Nov 27, 2022 (FC)
Comments: Shaded location rose represents where the vast majority of the natural activity occurred. Slides were in wind-loaded and sheltered terrain.

Terrain Use

N/A: driving/glassing looking at recent activity.