23-24

Hebgen

Date
Activity
Skiing

I skied above hebgen today, and was surprisingly the only one out there. The clouds opened up enough to see numerous 2-4’ deep slides that occurred over the past week, on slopes down to 29-30 degrees. Many started quite low on the mountain. There were several places where 27-28 degree slopes had shattered into cracks without sliding. 
I dug a pit on an east aspect at about 8200’, and found 130 cm of snow. An ECT failed at ECTP 29 at the interface of the basal junk and newer snow, about 90 cm down. Normally I would see this as an encouraging sign, but my pit today was purely academic and I skied dad pow all day. I did not experience any collapsing today, in stark contrast to the 2-300 collapses I got Nordic skiing around the hebgen basin yesterday. 

Region
Lionhead Range
Location (from list)
Hebgen Lake
Observer Name
Sam Reinsel

Remote Triggered Avalanche at Buck Ridge

Date
Activity
Snowmobiling

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. We knew conditions were dangerous and chose not to travel on or near steep slopes, but triggering an avalanche in the first hour of riding didn't make us feel great. Similar to what Dave said in his video we left here feeling as though the danger was higher than we thought. From here we continued on towards Muddy Creek and along the way saw a few natural avalanches in McAtee Basin and a small recent rider triggered avalanche in Third Yellow Mule. 

While signs of instability later in the afternoon were not obvious the glareing red flag from the morning had already set the tone for the day. Getting on or below terrain steeper than 30 degrees was not on the table and will remain off the table until conditions improve. 

 

Region
Northern Madison
Location (from list)
Buck Ridge
Observer Name
Zach Peterson

Beehive Basin Still Unstable

Date
Activity
Skiing

Pro 1 class pits and field observations:

Bottom Line: Still isn't looking good.

We toured out in Beehive Basin, conducted stability tests representative of of adjoining terrain. In 5/6 test pits we found the persistent weak layer is still problematic if you are going to get your skis or sled underneath the upper melt-freeze crust. There was also dramatic spacial variability of layers and reactivity even within a 50m x 50m area. This led us to believe that although there are tracks on the mountain, the button is still hiding waiting to be pushed.

The new storm layers have very poor bonding and are also capable of propagation. 

We observed two natural (assumption) slides one ridgeline back on lower Beehive Peak, leading us to conclude there is a possibility of small to medium size avalanches within the new snow layers in addition to the massive sleeping dragon at the bottom of the pack.

Region
Northern Madison
Location (from list)
Beehive Basin

Henderson Mountain Avalanche

Date
Activity
Snowmobiling

Observed a recent avalanche on Henderson Mountain East aspect today. 

Region
Cooke City
Location (from list)
Henderson Mountain
Observer Name
Ben Zavora

Skier triggered avalanche

Date
Activity
Skiing

End of Forest Service Wall outside of Big Sky Resort boundary. 

Region
Northern Madison
Location (from list)
NORTHERN MADISON RANGE

GNFAC Avalanche Forecast for Tue Feb 13, 2024

Snowpack and Avalanche Discussion

<p>Today is an avalanche accident waiting to happen. A powder-starved community and clearing skies will have excitement levels as elevated as the avalanche danger. Please do not get killed in an avalanche today.</p>

<p>Very dangerous avalanche conditions exist in the Bridger Range, where 10” of snow equal to 1.0” of <a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat… water equivalent</span></a> (SWE) fell in the last 24 hours. Natural and human-triggered avalanches breaking 1-2 feet deep are likely. Limit mountain travel to slopes less than 30 degrees and avoid avalanche runout zones.</p>

<p>New and wind-drifted snow is not bonding well to the old snow surface. Yesterday at the Throne, we triggered small avalanches by tapping our ski poles on steep slopes. With more snow, these will be much larger. Additionally, we triggered an enormous collapse on a wind-loaded slope, causing us to tuck our tails and retreat (<a href="https://www.youtube.com/watch?v=kFhSJq7vJ4M"><strong><span>video</span>…;). Similar slabs of wind-drifted snow avalanched naturally on Saddle Peak on Saturday afternoon (<a href="https://www.mtavalanche.com/node/30639"><strong><span>photo</span></str…;). The snowpack structure is very weak, and large avalanches breaking widely across slopes and running far into runout zones are on the table.</p>

<p><span>The danger is HIGH on all slopes.</span></p>

<p>Dangerous avalanche conditions exist in the mountains near Cooke City, West Yellowstone, Island Park, Big Sky and south of Bozeman. With new snow, we are again scratching the underbelly of an avalanche warning. Pioneer Mountain and Hyalite Canyon in the Northern Madison and Northern Gallatin Ranges came out on top with 7-10” of snow equal to 0.5-0.6” of SWE, while the rest of the area got 2-4” equal to 0.2” SWE.</p>

<p>Human-triggered avalanches breaking up to 4 feet deep and hundreds of feet wide are likely. Backcountry travelers have triggered slides from low-angle terrain above and below steep pitches with regularity this season due to persistent weak layers buried in the snowpack. This weekend, one group triggered three avalanches from low-angle terrain in Cooke City (<a href="https://www.mtavalanche.com/node/30678"><strong><span>photos and observation</span></strong></a>), a rider triggered a large slide on Lionhead Ridge from the safety of the flats (<a href="https://www.mtavalanche.com/node/30641"><strong><span>photo and observation</span></strong></a>), the same 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…;). The largest was an avalanche that broke 4 feet deep and 4000 feet wide in Tepee Basin last Wednesday (<a href="https://www.mtavalanche.com/node/30547"><strong><span>photos, video and description</span></strong></a>). These are a small collection of <em>nearly 50 entries </em>of natural and human-triggered slides recorded in our <a href="https://www.mtavalanche.com/avalanche-activity"><strong><span>avalanche activity log</span></strong></a> in the last week alone.</p>

<p>Conservative travel plans that stick to terrain less than 30 degrees are essential to coming home at the end of a fun day in the mountains. 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 all who participated and raised funds for The Friends of the GNFAC! The community came out big after a postponed event; participants were crushing boot pack laps and even getting some powder turns while fundraising for Friends of GNFAC. Top Fundraising teams were: Cooke City Exxon ($8,271), Science Saves Lives ($4,292), and Map Brewing Company ($1,905).

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