21-22

Natural avalanche on Scotch Bonnet

Scotch Bonnet
Cooke City
Code
SS-NC-R2-D2-I
Elevation
10000
Aspect
SE
Latitude
45.07330
Longitude
-109.94800
Notes

We saw a natural avalanche on 2/7 that appeared to occur late on 2/6 or early 2/7, on the southeast side of Scotch Bonnet Mtn. - GNFAC

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Cornice fall
R size
2
D size
2
Bed Surface
I - Interface between new and old snow
Problem Type
New Snow
Images
Natural wind slab on Scotch Bonnet
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
21-22

Rider-Triggered Avalanche SW face of Sheep Mountain

Sheep Mountain
Cooke City
Code
SS-AMu-R2-D2-O
Elevation
9900
Aspect
SW
Latitude
45.07220
Longitude
-109.92800
Notes

From Obs: "On the morning of Sunday February 6, a snowmobiler triggered a slide in new snow on the SW face of Sheep Mountain. The slide triggered remotely while the rider was lower on the slope and he was not caught (the visible track is not from the rider who triggered the slide, his track was buried in the debris field). The crown was about 18" deep and 75 feet wide and the slide and the slide ran about 250 feet."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
u-An unintentional release
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
18.0 inches
Vertical Fall
250ft
Slab Width
75.00ft
Weak Layer Grain type
Faceted Crystals
Weak Layer grain size
1.50mm
Weak Layer Hardness
F
Slab Layer Grain Type
Precipitation Particles
Images
Sheep Avalanche Profile - 7 Feb 2022
Rider-Triggered Avalanche SW face of Sheep Mountain
Attached Videos
Recent Avalanches, Unstable Snow, Cooke - 7 Feb 2022
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year
21-22

From Obs: "On the morning of Sunday February 6, a snowmobiler triggered a slide in new snow on the SW face of Sheep Mountain. The slide triggered remotely while the rider was lower on the slope and he was not caught (the visible track is not from the rider who triggered the slide, his track was buried in the debris field). The crown was about 18" deep and 75 feet wide and the slide and the slide ran about 250 feet." Photo: C Mozol

Avalanche Details: Rider-Triggered Avalanche SW face of Sheep Mountain
Forecast link: GNFAC Avalanche Forecast for Tue Feb 8, 2022
Cooke City, 2022-02-07
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    • Small, Skier-Triggered Avalanche Blackmore

    Mt Blackmore
    Northern Gallatin
    Code
    L-ASu-R1-D1
    Latitude
    45.44440
    Longitude
    -111.00400
    Notes

    From Obs: "We skied into Blackmore late yesterday with chief concerns of the weak layer @ around 110cm and wind loaded new slopes. We dug two pits and found no failures in our column or ECTs. With the wind on the ridge we dug a hasty pit near the ridge to see how it was bonding. Again no results.

    We decided to ski our lines taking care to avoid potential trigger zones and particularly loaded slopes. About half way down, I took a turn to the skier's left of a spine and the skier's right side had a small surface-level release. This would probably not have buried a skier, but likely would have taken them or a ride above the cliff band."

    Number of slides
    1
    Number caught
    0
    Number buried
    0
    Avalanche Type
    Loose-snow avalanche
    Trigger
    Skier
    Trigger Modifier
    u-An unintentional release
    R size
    1
    D size
    1
    Slab Thickness
    4.0 inches
    Images
    Small, Skier-Triggered Avalanche Blackmore
    Slab Thickness units
    inches
    Single / Multiple / Red Flag
    Single Avalanche
    Advisory Year
    21-22
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