23-24

Recent Natural and rider triggered slides in Sage Basin

Date
Activity
Snowmobiling

We took advantage of great visibility and rode in from Taylor Fork up to Sage Basin and then over the Beaver Slide and around Skyline Ridge into Cabin Creek. We saw three recent avalanches along the headwall of Sage Basin and one in Sunlight Basin. Two of the slides in Sage and the Sunlight slide looked to be naturals that broke a couple days ago. All of the slide looked to be 2-3 ft deep, breaking on the early season weak snow at the bottom of the pack. One of the slides in Sage broke ~700 ft wide. The other slide in Sage looked to have been remotely triggered by riders yesterday from ~100 ft away. 

Beautiful sunny weather and riding conditions today. No cracking or collapsing observed today.

It's going to be heads up as it starts snowing again. Expect to easily trigger avalanches if you get on or near any steep slopes in the next few days.

Region
Southern Madison
Location (from list)
Taylor Fork
Observer Name
Ian Hoyer

GNFAC Avalanche Forecast for Wed Feb 14, 2024

Snowpack and Avalanche Discussion

<p>Dangerous avalanche conditions exist across the advisory area, and large, human-triggered avalanches failing 2-4 feet deep on persistent weak layers are likely. Smaller avalanches may fail within the new or wind-drifted snow, but the gutless foundation of the season’s snowpack continues to drive decision-making.</p>

<p>In the last week alone, we have fifty entries from across the advisory area in our <a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity log</span></strong></a>. Many of these describe multiple slides. The mountains are communicating the avalanche danger clearly.</p>

<p>Yesterday, I got another wake-up call to this reality at Buck Ridge when I triggered an avalanche in First Yellowmule that released 3 feet deep and hundreds of feet wide while I was safely away from the slope in flat terrain (<a href="https://www.mtavalanche.com/node/30721"><strong><span>observation</span…;, <a href="https://www.youtube.com/watch?v=7F9kBArjRDc"><strong><span>video</span>…;). In the backcountry near Big Sky Resort, a group triggered an avalanche that piled debris deeply in a terrain trap. Thankfully, no one was caught or injured (<a href="https://www.mtavalanche.com/node/30714"><strong><span>observation and photo</span></strong></a>). In Cooke City, a group observed a fresh, natural avalanche on Henderson Mountain (<a href="https://www.mtavalanche.com/node/30715"><strong><span>observation and photo</span></strong></a>).</p>

<p>Due to the nature of this season’s persistent weak layers, triggering avalanches from long distances away is relatively common. This weekend, backcountry travelers remotely triggered avalanches in Cooke City (<a href="https://www.mtavalanche.com/node/30678"><strong><span>photos and observation</span></strong></a>), at Lionhead Ridge (<a href="https://www.mtavalanche.com/node/30641"><strong><span>photo and observation</span></strong></a>), near Big Sky (<a href="https://www.mtavalanche.com/node/30621"><strong><span>photo and observation</span></strong></a>), and in Island Park (<a href="https://www.mtavalanche.com/node/30642"><strong><span>video</span></str…;). Last week, riders triggered an avalanche from flat terrain that broke 4 feet deep and 4000 feet wide in Tepee Basin (<a href="https://www.mtavalanche.com/node/30547"><strong><span>photos, video, and description</span></strong></a>). Thankfully, everyone was far enough away from the runout zones, and no one was caught, injured or killed. Factor in the possibility of triggering avalanches on slopes far above your position, and use caution when traveling below steep slopes (<strong><a href="https://www.youtube.com/watch?v=_d5_vlY-bjg&amp;list=PLXu5151nmAvTk1fEF… angle video</a></strong>).</p>

<p>Conservative travel plans are essential. Selecting routes in terrain less than 30 degrees without steep slopes immediately above will keep you safe from avalanches. The danger is CONSIDERABLE.</p>

King and Queen of The Ridge Results

We closed out King and Queen (of the Apron) with $23,208 raised! A huge Thank You to Bridger Bowl and everyone who participated and raised funds for The Friends of the GNFAC! The community came out big after a postponed event, participants were crushing bootpack laps and even getting some powder turns while fundraising for Friends of GNFAC.

Small Rider Triggered Avalanche Buck Ridge

Buck Ridge
Northern Madison
Code
SS-AM-R2-D1.5-O
Elevation
9500
Aspect
NE
Latitude
45.17190
Longitude
-111.38000
Notes

A small rider triggered avalanche at the top of Third Yellowmule. 

 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
R size
2
D size
1.5
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Single Avalanche
Advisory Year

Natural Avalanches McAtee Basin

McAtee Basin
Northern Madison
Code
N
Aspect
W
Latitude
45.17710
Longitude
-111.43500
Notes

Several natural avalanches in McAtee Basin. These avalanches happened early in the morning following a recent storm. 

 

Number of slides
3
Number caught
0
Number buried
0
Trigger
Natural trigger
Slab Thickness units
centimeters
Single / Multiple / Red Flag
Multiple Avalanches
Advisory Year

Remote Triggered Avalanche at Buck Ridge

Buck Ridge
Northern Madison
Code
SS-AMr-R2-D2-O
Elevation
9400
Aspect
N
Latitude
45.17190
Longitude
-111.38000
Notes

We rode into Buck Ridge today and in First Yellow Mule, we triggered an avalanche 100' away from a flat meadow below. This avalanche broke several hundred feet wide and 3' deep on weak faceted snow low in the snowpack. This was right next to a slope that we had remotely triggered weeks ago on January 22nd, observation here

 

Number of slides
1
Number caught
0
Number buried
0
Avalanche Type
Soft slab avalanche
Trigger
Snowmobile
Trigger Modifier
r-A remote avalanche released by the indicated trigger
R size
2
D size
2
Bed Surface
O - Old snow
Problem Type
Persistent Weak Layer
Slab Thickness
36.0 inches
Vertical Fall
150ft
Slab Width
400.00ft
Weak Layer Grain type
Surface Hoar
Weak Layer grain size
8.00mm
Weak Layer Hardness
F
Slab Thickness units
inches
Single / Multiple / Red Flag
Single Avalanche
Advisory Year