19-20

Natural Avalanche on Lionhead Ridge

Lionhead Ridge
Lionhead Range
Code
SS-N-R2-D2-O
Latitude
44.71450
Longitude
-111.31800
Notes

Natural avalanche observed on 1/17 in Airplane Bowl off of Lionhead Ridge. Broke 2 ft deep and 150 ft wide.

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
R size
2
D size
2
Bed Surface
O - Old snow
Slab Thickness
24.0 inches
Slab Width
150.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Large natural avalanche near Hardscrabble Peak

Hardscrabble Peak
Bridger Range
Code
HS-N-R3-D3-O
Elevation
9000
Aspect
E
Latitude
45.91510
Longitude
-110.98100
Notes

Natural avalanche on 1/17 near Hardscrabble Peak in the Northern Bridgers.

From observation: "At some point between 12:00 and 15:00 a large natural slide occurred in 'October Bowl'. My partner and I saw no tracks in the area. We witnessed a large amount of snow being deposited on that aspect throughout the day. In the photos you can see the crown from 01/16 and the new crown up and to the right."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Hard slab avalanche
Trigger
Natural trigger
R size
3
D size
3
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
24.0 inches
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural avalanche on 1/16 near Hardscrabble Peak in the Northern Bridgers.

From observation: "At some point between 12:00 and 15:00 a large natural slide occurred in 'October Bowl'. My partner and I saw no tracks in the area. We witnessed a large amount of snow being deposited on that aspect throughout the day. In the photos you can see the crown from 01/16 and the new crown up and to the right."

Photo: R. Griffiths

Bridger Range, 2020-01-18

Natural avalanche on 1/17 near Hardscrabble Peak in the Northern Bridgers.

From observation: "At some point between 12:00 and 15:00 a large natural slide occurred in 'October Bowl'. My partner and I saw no tracks in the area. We witnessed a large amount of snow being deposited on that aspect throughout the day. In the photos you can see the crown from 01/16 and the new crown up and to the right."

Photo: R. Griffiths

Bridger Range, 2020-01-18

GNFAC Avalanche Forecast for Fri Jan 17, 2020

Snowpack and Avalanche Discussion

<p>Yesterday, snowmobilers triggered two large avalanches on Henderson Mountain near Cooke City. One of these slides was absolutely huge, breaking more than 10 feet deep in spots (<strong><a href="https://www.mtavalanche.com/images/20/huge-slide-henderson-close">photo…;). A large natural avalanche also broke yesterday near Hardscrabble Peak in the northern Bridger Range (<strong><a href="https://www.mtavalanche.com/images/20/large-natural-avalanche-northern-…;). It initially failed 2-3 ft deep and then stepped down to the ground.</p>

<p>Conditions aren’t hair trigger today. It’s been 48 hours since the last snowfall. While winds have continued to load some slopes, most slopes are handling the load well. However, as yesterday’s slides demonstrate, triggering a large avalanche is a very real possibility today that could have devastating consequences.</p>

<p>Figuring out whether a particular slope is primed to slide is going to be a real challenge and in some cases near impossible to do safely. Tracks are not a guarantee of stability. Wednesday’s sobering close call with a large skier triggered slide on Saddle Peak is a good reminder of this (<strong><a href="https://www.mtavalanche.com/node/21587">details</a></strong&gt;). A number of skiers had skied the very similar adjacent slopes without incident before one got unlikely, hit the wrong spot, and triggered a big avalanche.</p>

<p>Remember the big picture: many slopes have weak layers low in the snowpack and multiple large avalanches have been triggered on those layers each of the last three days (see the <strong><a href="https://www.mtavalanche.com/avalanche-activity">avalanche activity</a> page</strong> for a list of reported slides). Think long and hard before getting into avalanche terrain today. Be extra skeptical of slopes that have recently been windloaded or are getting activity loaded today.</p>

<p>Human triggered avalanches are possible and the avalanche danger is MODERATE today.</p>

<p>The snowpack is generally stable in the northern Gallatin Range with the exception of wind-drifted slopes. Strong winds have continued in Hyalite (gusts up to 60 mph overnight) but there is no more loose snow left to transport. While at this point most drifts will be well bonded, watch for shooting cracks as your sign you’ve found one that hasn’t yet. Avoid those slopes. For today, the danger is MODERATE on windloaded slopes and LOW on all others.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an&nbsp;<strong><a href="https://www.mtavalanche.com/node/add/snow_observation">observation form</a></strong>, email us (<strong><a href="mailto:mtavalanche@gmail.com">mtavalanche@gmail.com</a></strong&gt;), leave a VM at 406-587-6984, or Instagram (#gnfacobs).</p>

Upcoming Avalanche Education and Events

Our education calendar is full of awareness lectures and field courses. Check it out and plan to attend one or two: Events and Education Calendar.

COOKE CITY

Every Friday and Saturday, Snowpack Update and Rescue Training. Friday, 6:30-7:30 p.m. at the Soda Butte Lodge. Saturday anytime between 10-2 @ Round Lake.

BOZEMAN

Snowmobile Triggered Avalanche in Taylor Fork

Taylor Fork
Southern Madison
Code
SS-AMu-R1-D1-G
Aspect
E
Latitude
45.06070
Longitude
-111.27200
Notes

A small but relatively deep avalanche triggered by a snowmobiler on Tuesday, 1/14/2020. 30 ft wide. Ran 20 vertical feet. This avalanche broke to 2-3 ft deep, to the ground. This is the second time this year this slope has slide, it also avalanched in mid-December.

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
1
D size
1
Bed Surface
G - Ground
Problem Type
Persistent Weak Layer
Slab Thickness
24.0 inches
Vertical Fall
20ft
Slab Width
30.00ft
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

A small but relatively deep avalanche triggered by a snowmobiler on Tuesday, 1/14/2020. 30 ft wide. Ran 20 vertical feet. This avalanche broke to 2-3 ft deep, to the ground. This is the second time this year this slope has slide, it also avalanched in mid-December. Photo: GNFAC

Southern Madison, 2020-01-16