21-22

Skier Triggered Avalanche North of Bridger Bowl

Bridger Bowl
Bridger Range
Code
SS-AS-O
Latitude
45.81560
Longitude
-110.92300
Notes

BBSP reported a skier-triggered avalanche north of the ski area boundary. Minimal information. No one was caught that we know of. 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Bed Surface
O - Old snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural Avalanche Cedar Mountain

Cedar Mtn.
Northern Madison
Code
N-R2-D2
Elevation
9900
Aspect
NE
Latitude
45.22680
Longitude
-111.51200
Notes

Patrollers at the Yellowstone Club spotted a natural avalanche on a steep, wind-loaded slope that failed on March 20th. 

Number of slides
1
Number caught
0
Number buried
0
Trigger
Natural trigger
R size
2
D size
2
Problem Type
Wind-Drifted Snow
Vertical Fall
400ft
Slab Width
150.00ft
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural Avalanches Divide Peak Basin

Divide Cirque
Northern Gallatin
Code
SS-N-I
Latitude
45.39340
Longitude
-110.96900
Notes

A snow surfer reported many natural avalanches breaking in the Divide Cirque running from wind-loaded terrain near ridgelines most of the length of the slopes. Avalanches failed at or near the interface with the 12" of snow from this weekend. 

Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Natural trigger
Bed Surface
I - Interface between new and old snow
Problem Type
Wind-Drifted Snow
Slab Thickness
12.0 inches
Slab Thickness units
inches
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Skier Triggered Avalanche Saddle Peak

Saddle Peak
Bridger Range
Code
SS-ASu-R2-D2
Elevation
8250
Aspect
E
Latitude
45.79430
Longitude
-110.93600
Notes

A skier triggered an avalanche mid-slope on Saddle Peak in the Bridger Range early afternoon March 21st. Thankfully the individual was able to ski out of the slide.

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
2
Problem Type
Wind-Drifted Snow
Vertical Fall
500ft
Slab Width
100.00ft
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Storm snow

Date
Activity
Snowboarding

I was up at divide yesterday (Sunday) to surf and rode the east divide shoulder , conditions were blower 

the storm came in hot ….1” per hr with a storm total yesterday when I took off at 12” in the basin 

any steep roll overs were sluffing naturally or when ridden over 

the storm slabs did not step down but we’re sliding on the new/old snow interface 

today I went back to divide and snowboarded and got up there early to beat the sun

 

it was hard to get a photo but pretty much the entire divide basin had slides on the storm snow what ran the entire length of the slopes…there were a few off divide pk proper 

each slide stared at the ridge from wind/ snow loading 

 

I took off at 1 today from the basin because everything was getting cooked and roller balls were starting and the snow quality was deteriorating 

Region
Northern Gallatin
Location (from list)
Divide Peak

Easy sluffing Wolverine bowl

Wolverine Bowl
Bridger Range
Code
L-ASc-R1-D1.5-I
Aspect
NE
Latitude
45.83010
Longitude
-110.93400
Notes

From obs: "2 ski cuts in the top of the bowl and it ran most of the way to the bottom. Skiing next to the path, 4 turns would generate enough sluff that you had to get out of the way. No slab releases but the sluff could knock you down if you weren’t looking out for it."

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Loose-snow avalanche
Trigger
Skier
Trigger Modifier
c-A controlled or intentional release by the indicated trigger
R size
1
D size
1.5
Bed Surface
I - Interface between new and old snow
Problem Type
New Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

GNFAC Avalanche Forecast for Mon Mar 21, 2022

Snowpack and Avalanche Discussion

<p>The 48-hour storm total in the mountains around Bozeman and Big Sky is 6-10” equal to 0.6-0.8” of snow water equivalent (<a href="https://www.nrcs.usda.gov/wps/portal/nrcs/detail/null/?cid=nrcseprd1314…;) with 2-5” (0.2-0.3” SWE) near West Yellowstone and Cooke City. Winds remained light through the storm, exceptions to this are periods of moderate winds in the Bridger and North Gallatin Range and the mountains near Cooke City.</p>

<p>With higher storm totals, new snow avalanches will be deeper and more dangerous near Bozeman and Big Sky. Skiers in Hyalite Canyon and the Beehive Basin area saw natural avalanches that failed yesterday below the new snow (<a href="https://www.mtavalanche.com/node/26282"><strong>Hyalite photo and details</strong></a><strong>, </strong><a href="https://www.mtavalanche.com/node/26281"><strong>Beehive details</strong></a>). The Big Sky Ski Patrol reported the storm snow was “extremely sensitive” to triggers. This weekend’s snow remains a concern today. Additionally, as temperatures climb this afternoon, the recent snow will be more likely to slide on slopes getting hit by the spring sun.</p>

<p>Slopes across the advisory area with recent drifts of wind-loaded snow are suspect. Yesterday, the Bridger Bowl Ski Patrol noted that the wind was rapidly forming slabs near ridgelines and under cliffs that readily broke 6-18” deep. This weekend sections of cornice broke and triggered avalanches near Lionhead (<a href="https://www.youtube.com/watch?v=xc770oqXMsE&amp;list=PLXu5151nmAvT1nrM2…;, <a href="https://www.mtavalanche.com/node/26265"><strong>photos and details</strong></a>) and in the Republic Creek drainage (<a href="https://www.mtavalanche.com/node/26275"><strong>photo and details</strong></a>). Last week, similar avalanches failed on <a href="https://www.mtavalanche.com/node/26230"><strong>Saddle Peak</strong></a>, <a href="https://www.mtavalanche.com/node/26195"><strong>Buck Ridge</strong></a> and <a href="https://www.mtavalanche.com/node/26199"><strong>Mount Blackmore</strong></a>. Treat slopes commonly loaded by the wind and near ridgelines with added caution.</p>

<p>Large avalanches are possible due to persistent weak layers buried 1-3’ deep on many slopes. On Saturday, skiers in Bear Basin made a hasty retreat after they triggered an audible collapse in the snowpack (<a href="https://www.mtavalanche.com/node/26274"><strong>details</strong></a&gt;). Last week, natural avalanches broke on Crown Butte and Miller Mountain, skiers triggered a slide near Mount Abundance and a natural avalanche broke an estimated 1,000’ wide on Cedar Mountain. See these and all reported avalanche activity on our <a href="https://www.mtavalanche.com/avalanche-activity"><strong>activity log</strong></a>.</p>

<p>This adds up to tricky avalanche conditions. Many slopes are stable, similar to what Doug and I found at the Throne yesterday (<a href="https://www.youtube.com/watch?v=6UH-zaFfU3c"><strong>video</strong></a&…;), but safe travel in and around avalanche terrain requires thorough snowpack assessments and a willingness to heed warning signs if you observe indicators of instability. Human-triggered avalanches are possible, and the danger is MODERATE.</p>

<p>If you get out, please send us your observations no matter how brief. You can submit them via our website, email (mtavalanche@gmail.com), phone (406-587-6984), or Instagram (#gnfacobs).</p>

Easy stuffing Wolverine bowl

Date
Activity
Skiing

2 ski cuts in the top of the bowl and it ran most of the way to the bottom. Skiing next to the path, 4 turns would generate enough sluff that you had to get out of the way. No slab releases but the sluff could knock you down if you weren’t looking out for it.

Region
Bridger Range
Location (from list)
Wolverine Bowl
Observer Name
P Hinz