19-20

Many natural and skier triggered wind slabs in Bridgers

Bridger Range
Code
SS-AS
Aspect
E
Latitude
45.77010
Longitude
-110.94000
Notes

Observations from Bridger Ski Patrol:

"At 10:30 am natural avalanches were reported Between the Peaks of Saddle, in Argentina Bowl, and on Bridger Peak.  At 11am a solo skier trigger an avalanche on the north peak of Saddle with a cornice drop.  Shortly after, skier triggered avalanches were reported to the north, in Peter's Point, and Barny and Gibbs."

From a skier:

"Really touchy windslab formation throughout the day. 6-12 in slabs running on freeze crust."

Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Skier
Problem Type
Wind-Drifted Snow
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

GNFAC Avalanche Forecast for Tue Mar 10, 2020

Snowpack and Avalanche Discussion

<p>The mountains around Cooke City and the Northern Gallatin and Madison Ranges received 8-10” of new snow last night bringing the three-day total to 15-20” at upper elevations. West to northwest winds are depositing snow on slopes that could avalanche today. Look for thick drifts and shooting cracks coming from your ski tips or sled as these indicate unstable slopes. This weekend skiers released a slab in a 40-degree chute in Middle Basin (<a href="https://www.mtavalanche.com/node/22376"><strong>details</strong></a><st…; </strong><a href="https://www.mtavalanche.com/node/22376"><strong>and photos</strong></a>) and observed loose snow avalanches on the east face of Mount Blackmore on Sunday (<a href="https://www.mtavalanche.com/node/22370"><strong>details and photo</strong></a>). Today, similar avalanches are possible in steep terrain. Avalanches breaking deeper into the snowpack are unlikely today, but, as a cornice triggered slide in Hyalite Canyon indicates, they are still an outside possibility (<a href="https://www.mtavalanche.com/node/22360"><strong>photo, video and details</strong></a>). In a video from <strong><a href="https://youtu.be/cfTGLhhLY6Y">Beehive Basin</a></strong> on Sunday we outline these issues.</p>

<p>Today, avoid wind loaded slopes and assess snowpack stability prior to entering avalanche terrain. Human triggered avalanches are possible, and the <u>dry snow danger</u> is rated MODERATE.</p>

<p>The Bridger, Southern Madison, Southern Gallatin and Lionhead Ranges received 8-12” of new snow since Saturday night. On Sunday the new snow avalanched under the weight of skiers and riders on Saddle Peak piling debris 5-6’ deep (<a href="https://www.mtavalanche.com/node/22371"><strong>details</strong></a&gt;). The new snow gained strength since Sunday and, yesterday, in the Taylor Fork I found that dry snow avalanches would be unlikely and if they occurred they would be limited to the new snow (<a href="https://youtu.be/j4iwxKEFQcY"><strong>Skyline Ridge video</strong></a>). Remember that low danger does not equal no danger and in steep technical terrain, a small avalanche can have large consequences.</p>

<p>Today, give cornices a wide berth as they may break far back from the edge, assess slope stability and follow safe travel protocols. The <u>dry snow danger</u> is rated LOW and human triggered avalanches are unlikely.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an <a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e…; target="_blank">observation form</a>, email us (<a href="mailto:mtavalanche@gmail.com&quot; target="_blank">mtavalanche@gmail.com</a>), 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

March 13 and 14, Friday and Saturday, (last of the season) 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

GNFAC Avalanche Forecast for Mon Mar 9, 2020

Snowpack and Avalanche Discussion

<p>Dry snow avalanches will be the primary avalanche concern today. These avalanches will likely be confined to the 3-9” of new snow from the last 36 hours and will slide on a thick melt-freeze crust. Watch for signs of increasing instability such as shooting cracks and collapsing as snow begins to fall later today. Yesterday provided numerous examples of the likely hazard. Skiers on Saddle Peak triggered avalanches that broke 8” deep and piled debris 5-6’ deep in the runouts (<a href="https://www.mtavalanche.com/node/22371"><strong>details</strong></a&gt;). On Mount Blackmore, tourers reported dry, loose snow avalanches on the east face (<a href="https://www.mtavalanche.com/node/22370"><strong>details and photo</strong></a>). This new snow hazard was our primary concern in Beehive Basin (<a href="https://youtu.be/cfTGLhhLY6Y"><strong>video</strong></a&gt;). As people are stepping out into more varied terrain, they will find areas of isolated instability such as a group in Middle Basin that intentionally released a storm slab in a 40-degree chute with a ski cut (<a href="https://www.mtavalanche.com/node/22376"><strong>details</strong></a><st…; </strong><a href="https://www.mtavalanche.com/node/22376"><strong>and photos</strong></a>). In high consequence terrain like this, a small avalanche can push a skier or rider off cliffs and into obstacles. Do not underestimate the risks of small avalanches in this context.</p>

<p>In addition to new snow avalanches, cornices are a significant hazard as they have grown large and will break far back from the edge triggering avalanches failing on deeper weak layers on slopes below. An intentional cornice drop and subsequent avalanche in the Northern Gallatin Range on Saturday provides an excellent example of this (<a href="https://www.mtavalanche.com/node/22360"><strong>photo, video and details</strong></a>).</p>

<p>Yesterday, climbers and skiers reported wet loose avalanches at lower elevations (<a href="https://www.mtavalanche.com/node/22372"><strong>details</strong></a&gt;). Today, the wet avalanche hazard will be limited, but sinking into a wet and unsupportable snowpack is an indicator that the snowpack has lost cohesion and could avalanche. Learn more about wet snow avalanches in Ian’s <a href="https://youtu.be/H5030DBBQhQ"><strong>video</strong></a&gt; from Mount Ellis. This hazard is most likely found on lower elevation slopes with more exposure to the sun.</p>

<p>Today, follow standard safe travel protocols, assess the snowpack for isolated instabilities and carefully manage the hazard of avalanches if you choose to step out into steep terrain. The <u>dry snow</u> danger is LOW. With overcast skies and light snow, the <u>wet snow</u>&nbsp;avalanche danger is LOW.</p>

<p>If you get out, please send us your observations no matter how brief. You can fill out an <a href="https://mtavalanche.us17.list-manage.com/track/click?u=6653a830e4819c9e…; target="_blank"><strong>observation form</strong></a>, email us (<a href="mailto:mtavalanche@gmail.com&quot; target="_blank"><strong>mtavalanche@gmail.com</strong></a>), 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

March 13 and 14, Friday and Saturday, (last of the season) 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