23-24

BSSP explosive triggered very large slide on NSS

Lone Mountain
Northern Madison
Code
HS-ABc-R4-D3.5-O
Elevation
11000
Aspect
N
Latitude
45.27770
Longitude
-111.45100
Notes

From email 1/26/24: "The NSS avalanched R3/4, D3.5 on a 6lb. shot on a stick. There were multiple basal layers involved, including gouging to the ground. Big avalanche and not a surprise. That zone has been filling in, growing in volume, and hardening in the wind.... Unsurprisingly, it did not take much added intensity to make it avalanche."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
An explosive detonated above the snow surface (air blast)
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
4
D size
3.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Collapsing and cracking in emigrant basin

Date
Activity
Snowboarding

20ft diameter collapse on shallow slope, 25-30 inch snowpack, bottom 10inches to ground rotten and ball bearing like. 
 

Shooting crack in a gulley, evidence of previous avalanche present in same gulley 

Location (from list)
Emigrant Peak
Observer Name
D. Britt

Big avalanche in 2nd YellowMule

Buck Ridge
Northern Madison
Code
Latitude
45.17190
Longitude
-111.38000
Notes

From IG message 1/26/24: "2nd yellowmule. Main north facing ridge. Whole thing ripped out. Appears like yesterday, but unsure. Massive slide."

Number of slides
1
Number caught
0
Number buried
0
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Many natural avalanches along Lionhead Ridge

Lionhead Ridge
Lionhead Range
Code
SS-N-R1-D2
Latitude
44.71450
Longitude
-111.31800
Notes

Rode along Lionhead Ridge from Denny Creek to Watkins Creek and around into the head of Targhee Creek on 1/26/24. Saw dozens of avalanches that broke within the last week. Most of the slides looked to have broken early this week. 1/23/24 date is approximate. Slides broke on all aspects, both above treeline and well below treeline, and on both wind-loaded and nonwind-loaded slopes. All these slides looked to have broken on one of the December surface hoar layers at the top of the early season facets.

 

Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
1
D size
2
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

From IG message 1/26/24: "2nd yellowmule. Main north facing ridge. Whole thing ripped out. Appears like yesterday (01/25,2024), but unsure. Massive slide." Photo: R. Malmstrom

Northern Madison, 2024-01-26

A slide in Watkins Creek broke across three avalanche paths/gully features and was one of the larger slides we've seen this season, looking to have piled up debris 10+ ft deep. Looks to have broken in the last 24 hours. 1/26/24 Photo: GNFAC

Lionhead Range, 2024-01-26