22-23

From obs 5/7/23: "Natural R3-4, D4 ripped out a large chunk of the south face of Wilson during the last warm period I would assume. Debris everywhere and one large boat-sized pile even scoured a path further down than the rest of the debris. Looked to be a mix of wet loose and wet slab release from high up. Alpha angle at the bottom of the debris was 25 degrees" Photo: C. Ellingson

Northern Madison, 2023-05-09

Large Natural Avalanche on Wilson Pk

Date
Activity
Skiing

Natural R3-4, D4 ripped out a large chunk of the south face of Wilson during the last warm period I would assume. Debris everywhere and one large boat-sized pile even scoured a path further down than the rest of the debris. Looked to be a mix of wet loose and wet slab release from high up. Alpha angle at the bottom of the debris was 25 degrees

Region
Northern Madison
Location (from list)
Wilson Peak
Observer Name
Colton Ellingson

Several large wet slides in north bowl

Bridger Bowl
Bridger Range
Code
WL-N-R3-D2.5
Elevation
8000
Aspect
E
Latitude
45.81560
Longitude
-110.92300
Notes

Pictures from this morning (May 1) but I’m sure these all ran late last week. They took out at least one or two skin tracks set during the big dump (40”) that ran right up the center.

Unconsolidated, dripping wet snow this morning mid mountain around 830 AM. Top 3-4” had frozen but soft by 830.

Number of slides
5
Number caught
0
Number buried
0
Avalanche Type
Wet loose-snow avalanche
Trigger
Natural trigger
R size
3
D size
2.5
Problem Type
Wet Snow
Vertical Fall
1000ft
Snow Observation Source
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Recent Wet Avalanches in the T-Roots

Tobacco Root Mountains
Out of Advisory Area
Code
WS-N-R2-D3
Elevation
8500
Aspect
E
Latitude
45.60750
Longitude
-112.12800
Notes

While touring into the Dry Boulder Creek drainage, we noticed remnants of many recent wet loose slides, and one significant wet slab avalanche. The wet loose slides had occurred on all aspects, including low-elevation north facing slopes. I estimate that most of the wet loose slides we observed were no larger than R2 for their respective paths, and most were D2, with some large, high elevation slides, reaching a possible D3.

We observed the remnant of one large wet slab on an east facing slope at around 8500 ft. I estimated the crown to be around 500 ft wide, and 5 feet deep at its maximum. I estimate this slide was a R2 D3, with an unknown natural trigger.

We took these observations into account, staying off of solar aspects, and staying out of avalanche terrain once the snow began to soften.

Number of slides
4
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
2
D size
3
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

natural wet slab avalanche, south of Cooke City

COOKE CITY
Cooke City
Code
WS-N-R3-D2.5-O
Elevation
8500
Aspect
N
Latitude
45.01060
Longitude
-109.94700
Notes

A natural wet slab avalanche that occurred just south of Cooke City yesterday May 3, around 6pm.

The slide is on a northerly spect around 8500'.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
3
D size
2.5
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness
30.0 inches
Vertical Fall
750ft
Slab Width
200.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

natural wet slab avalanche, south of Cooke City

Date

A natural wet slab avalanche that occurred just south of Cooke City yesterday May 3, around 6pm.

The slide is on a northerly spect around 8500'.

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
B. Fredlund

recent natural wet avalanche north of Cooke City

COOKE CITY
Cooke City
Code
WS-N-R3-D2.5-O
Elevation
10500
Aspect
SW
Latitude
45.10440
Longitude
-109.89900
Notes

Natural wet slab avalanche, north of Cooke City, which likely happened on April 30th (observed May 1).

It's on a SW aspect, about 10,500'.  Crown estimated to be 4-6' deep.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
3
D size
2.5
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness
48.0 inches
Vertical Fall
500ft
Slab Width
300.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

From obs. “Natural wet slab avalanche, north of Cooke City, which likely happened on April 30th (observed May 1).

It's on a SW aspect, about 10,500'.  Crown estimated to be 4-6' deep.” Photo: B. Fredlund

Cooke City, 2023-05-03

recent natural avalanche activity north of Cooke City

Date
Activity
Skiing

Natural wet slab avalanche, north of Cooke City, which likely happened on April 30th (observed May 1).

It's on a SW aspect, about 10,500'.  Crown estimated to be 4-6' deep.

Region
Cooke City
Location (from list)
COOKE CITY
Observer Name
B. Fredlund