20-21

Huge wet slab on Beartooth Pass

Beartooth Pass
Out of Advisory Area
Code
WS-N-R3-D3-O
Elevation
10000
Aspect
N
Latitude
44.96910
Longitude
-109.47200
Notes

This huge avalanche occurred Friday June 4, 2021 near Beartooth Basin ski area, above Twin Lakes on Beartooth Pass. Multiple days of exceptionally warm temperatures followed by rain caused a large cornice to break and trigger the nearly 10' deep wet slab

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
3
D size
3
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Skier triggered and natural new snow avalanches in Beehive

Beehive Basin
Northern Madison
Code
SS-AS-R1-D1.5-I
Elevation
10000
Aspect
NE
Latitude
45.34070
Longitude
-111.39100
Notes

From obs: 5/9/21: "Yesterday we went to check out the new snow in Beehive Basin.... While traversing... along the north ridge of 10602, we triggered a small wind slab  that carried down into Peruvian, which then released another small wind slab on a northeast aspect of the face (photo). The crown height of this wind slab was measured at 60cm at it's deepest point, and approximately 30ft wide by 10ft long.

Looking down into the face of Peruvian, we observed a natural dry loose slide that released from the ridge. We observed an increase in wind speed throughout the morning, and a shift in wind direction from west to southwest in the early morning moving to west to north west by the late morning."

Number of slides
2
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
R size
1
D size
1.5
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
60.0 centimeters
Slab Width
30.00ft
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Loose dry release in Peruvian

From obs: 5/9/21: "Yesterday we went to check out the new snow in Beehive Basin... Looking down into the face of Peruvian, we observed a natural dry loose slide that released from the ridge... We observed an increase in wind speed throughout the morning, and a shift in wind direction from west to southwest in the early morning moving to west to north west by the late morning. The combination of variable and high winds with the amount of new snow available for transport created a noticeable increase in the hazard of wind slabs on all aspects we observed during the morning..." Photo: E.

Northern Madison, 2021-05-10

Crown of skier triggered wind slab

From obs: 5/9/21: "Yesterday... While traversing... along the north ridge of 10602 [near Beehive], we triggered a small wind slab  that carried down into Peruvian, which then released another small wind slab on a northeast aspect of the face (photo). The crown height of this wind slab was measured at 60cm at it's deepest point, and approximately 30ft wide by 10ft long. Looking down into the face of Peruvian, we observed a natural dry loose slide that released from the ridge.

Northern Madison, 2021-05-10

Debris from skier triggered wind slab in Beehive

From obs: 5/9/21: "Yesterday... While traversing... along the north ridge of 10602 [in Beehive], we triggered a small wind slab  that carried down into Peruvian, which then released another small wind slab on a northeast aspect of the face (photo). The crown height of this wind slab was measured at 60cm at it's deepest point, and approximately 30ft wide by 10ft long. Looking down into the face of Peruvian, we observed a natural dry loose slide that released from the ridge.

Northern Madison, 2021-05-10

ECT after shear, moist/wet snowpack

From obs 5/9//21: "Yesterday we went to check out the new snow in Beehive Basin. We dug a pit on the south face of Peak 10602, and conducted an ECT with results ECTN8@20, ECTN11@30, and ECTN25@60. The new snow total in this location was 30cm. Although we saw no propagation, a hand shear test (photo) and a shear conducted on the remaining ECT block (photo) resulted in a Q1 shear at the interface at the bottom of the new snow.

Northern Madison, 2021-05-10

Wet snow slides, natural and skier triggered

Taylor Fork
Southern Madison
Code
WS-N-R2-D2-O
Elevation
9500
Aspect
NW
Latitude
45.06070
Longitude
-111.27200
Notes

Multiple wet slides were reported in southern Madison and Tobacco Roots over the week 5/3-5/7.

Number caught
0
Number buried
0
Avalanche Type
Wet slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Wet Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year