23-24

Rider/skier triggered avalanche

Sheep Mountain
Cooke City
Code
SS-ASu-R2-D1.5-I
Elevation
9500
Aspect
NE
Latitude
45.07220
Longitude
-109.92800
Notes

From email 5/1/24: "Hi crew. I triggered a soft slab avalanche on the North side of Sheep Mountain today. D1.5 200’ wide ran 200’.  Crown was 6-12’’ deep. I was able to ride out of it and anchor in a safe spot. 

It broke on our 7th lap and we had seen no signs of instability prior to the avalanche but wind loading was occurring and obvious. The avalanche broke and on a dirty crust that formed during a rain event last week."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Trigger Modifier
u-An unintentional release
R size
2
D size
1.5
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
10.0 inches
Slab Width
200.00ft
Snow Observation Source
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

From email 5/1/24: "Hi crew. I triggered a soft slab avalanche on the North side of Sheep Mountain today. D1.5 200’ wide ran 200’.  Crown was 6-12’’ deep. I was able to ride out of it and anchor in a safe spot. 

It broke on our 7th lap and we had seen no signs of instability prior to the avalanche but wind loading was occurring and obvious. The avalanche broke and on a dirty crust that formed during a rain event last week."

Cooke City, 2024-05-01

Rider/skier triggered avalanche

Date

From email 5/1/24: "Hi crew. I triggered a soft slab avalanche on the North side of Sheep Mountain today. D1.5 200’ wide ran 200’.  Crown was 6-12’’ deep. I was able to ride out of it and anchor in a safe spot. 

It broke on our 7th lap and we had seen no signs of instability prior to the avalanche but wind loading was occurring and obvious. The avalanche broke and on a dirty crust that formed during a rain event last week."

Region
Cooke City
Location (from list)
Sheep Mountain

Signs of stability at BBowl

Date
Activity
Skiing

Toured up to Bradley's Meadow, and found about 6 inches of moderate density snow sitting on a thin M/F crust with wet snow underneath the pack. 

Snow seemed well bonded and did not see any natural slides up on ridge. Not much sun was out, and it was snowing until 12 p.m. 

Region
Bridger Range
Location (from list)
Bridger Bowl
Observer Name
M. Standal

GNFAC Avalanche Forecast for Mon Apr 29, 2024

Snowpack and Avalanche Discussion

<p><span><span><span><span><span><span>Over the next few days avalanches will primarily involve the recent snow and more snow that falls. Avalanches could range from fresh slabs of wind-drifted snow to wet-loose avalanches. Watch for blowing snow at ridgelines and cracking around your feet or skis as a sign that fresh, unstable drifts exist. If there is sunshine the new snow will quickly become moist and easily slide on sunny, steep slopes. Avalanches could be large, especially where there is more new snow, but even small slides can easily catch and carry you. Minimize exposure to terrain traps like cliffs, rocky outcrops and trees.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>On Friday there were natural wet slab avalanches near Cooke City (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31908"><span><span><span><strong><span…;), and skiers in Beehive Basin experienced loud collapses on a wet and unsupportable snowpack (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31904"><span><span><span><strong><span…;). I skied north of Cooke City the last couple days, and on Saturday found wet unsupportable snow up to 10,000’ (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/31921"><span><span><span><strong><span…;). Large wet slabs, and wet-loose avalanches deeper than the new snow, are not as likely the next few days due to light freezes the last couple nights and cold temperatures in the forecast. However, there is uncertainty of how well the snowpack froze below the new snow, and conditions could change quickly if there is more sunshine and warmth than expected. If you find a wet unsupportable snowpack, or the sun comes out and starts to melt the snow surface, seek lower angle or colder slopes.</span></span></span></span></span></span></p>

<p><span><span><span><span><span><span>Lower elevations are showing dirt and grass, but snow in the mountains means avalanches are possible. Remain diligent with careful snowpack assessment and route-finding, and carry proper avalanche rescue gear.&nbsp;</span></span></span></span></span></span><span><span><span><span><span><span>The variable and quickly changing spring weather creates a mix of avalanche concerns to watch for. The snowpack can change drastically from day to day, throughout the day, and across different aspects and elevations. Carefully evaluate the snowpack throughout the day, and have alternate plans in case you find unstable snow. See below for general spring snowpack and travel advice.</span></span></span></span></span></span></p>

Give Big Gallatin Valley is May 2-3, 2024. 

On May 2-3, please support the excellent non-profits of Gallatin County, including the Friends of the Avalanche Center (GNFAC Giving Page HERE