GNFAC Avalanche Forecast for Mon Jan 27, 2025
<p>In the mountains around Bozeman and Big Sky, the wind is transporting recent snow into unstable drifts at many elevations. <strong>Wind slab avalanches </strong>are the primary concern.</p>
<p>Skiers north of Bridger Bowl triggered an avalanche on a wind-loaded slope that broke a foot deep and twenty feet wide (<a href="https://www.mtavalanche.com/node/33857"><strong><span>observation</span…;), while others noted cracks in wind-drifted snow shooting from their ski tips (<a href="https://www.mtavalanche.com/node/33851"><strong><span>observation</span…;). Local Ski Patrols triggered <strong>wind slab avalanches </strong>that broke 6-18” deep during routine mitigation work. On many slopes, recent snow and wind slabs sit on weak layers of surface hoar and facets, slowing stabilization (Buck Ridge <a href="https://www.mtavalanche.com/node/33832"><span>observation</span></a>, Divide Basin (<a href="https://www.mtavalanche.com/node/33810"><span>observation</span></a>, Beehive Basin <a href="https://www.mtavalanche.com/node/33824"><span>observation</span></a>).</p>
<p>Avoid steep wind-loaded terrain, opting for sheltered slopes, where the surface conditions will be better, and avalanche conditions will be safer. Visual clues, a stiffening snow surface, and signs of instability, including avalanche activity and shooting cracks, can help us identify concerning terrain features.</p>
<p>In non-wind-loaded terrain, assess the upper few feet of the snowpack for instability before considering steeper slopes. Follow safe travel protocols, carry avalanche safety equipment and carefully evaluate terrain to consider the consequences of potential slides.</p>
<p><strong>*** Ice climbers</strong> in steep, confined gullies should watch for roller balls and wet loose avalanches coming from rocky areas above during the heat of the day. Shady aspects will have lower wet snow hazard.</p>
<p><span>The avalanche danger is MODERATE.</span></p>
<p>Time and the absence of significant loading allowed the snowpack to adjust and stabilize in the mountains of Island Park, West Yellowstone, and Cooke City, as well as in the Southern Gallatin and Southern Madison Ranges. While avalanches are unlikely, they are not impossible, and a very large slide south of Cooke City last week demonstrates their potential (<a href="https://www.mtavalanche.com/node/33847"><strong><span>photo</span></str…;).</p>
<p>We are encouraged by minimal avalanche activity, the generally small size of slides, the lack of signs of instability and unremarkable test results (<a href="https://youtube.com/shorts/wYfXLeIfQ38"><strong><span>Lionhead video</span></strong></a><strong>, </strong><a href="https://youtube.com/shorts/zUjqH2ol3u8"><strong><span>Cooke City video</span></strong></a>). As Mark stated in the Lionhead video, “The weak layers are dormant, not dead.” <strong>Persistent slab avalanches</strong> remain the primary concern, and conditions will become more dangerous again when it snows. For now, generally safe avalanche conditions exist.</p>
<p>Isolated <strong>wind slab avalanches </strong>breaking within recent drifts are a secondary concern. This is especially true in steep and technical terrain, where a small avalanche can have significant consequences.</p>
<p><strong>Travel Advice:</strong> Just because the danger dropped to low <strong><em>doesn’t</em></strong><em> mean you should shred all avalanche terrain on day one. </em>Avoid the highest-consequence slopes—very steep and large faces and avalanche paths with terrain traps such as cliffs, trees, and gullies where isolated instability would be fatal. If you elect to travel in avalanche terrain, look for signs of isolated instability, follow safe travel protocols, expose only one person at a time to potential risk, and ensure everyone carries avalanche safety gear.</p>
<p><span>The avalanche danger is rated LOW. </span></p>
KING AND QUEEN OF THE RIDGE
Do you like to hike? Do you like to ski/ride? Then the King & Queen of the Ridge on 2/1 is for you. Hike, ride and raise money for the Friends of the Avalanche Center at Bridger Bowl this year! Join this fun event to promote and support avalanche safety and awareness! Fundraising prizes for the top 5 individuals who raise over $500. No racing is necessary to compete for the fundraising prizes.
Weather and Avalanche Log for Mon Jan 27, 2025
Strong wind at all elevations in the Bridger Range
Shooting Cracks in the Bridgers
From obs: "We skied north from Texas Meadows to the Playground. Strong southerly winds were actively building wind slabs up to 25 cm deep in immediate lees at treeline. We experienced a few instances of cracking in this wind slab, propagating 2 or 3 meters from our ski tips."
In the Playground area of the Bridger Range, strong winds rapidly built wind slabs up to 25 cm deep around treeline. Skiers experienced a few cracks in this wind slab, propagating 2 or 3 meters from our ski tips. Photo: N. deLeeuw
Forecast link: GNFAC Avalanche Forecast for Mon Jan 27, 2025
Small wind slab avalanche in the Playground
From obs: "We triggered a small soft slab avalanche when skinning near the top of Pair Of Chutes in the Playground. The slab was about 1 foot thick, fist hardness, propagated 20 feet wide and ran 50 feet before breaking up and arresting. The slab did not entrain additional snow as it slid. The avalanche hit my feet but did not disturb my balance. However, it could have been dangerous above consequential terrain. Moderate gusting to high winds were sustained the entire day and wind slabs were widespread in the backcountry terrain north of Bridger."
Skiers triggered a small wind slab avalanche while skinning near the top of Pair Of Chutes in the Playground. The slab was about 1 foot thick, fist hardness, propagated 20 feet wide and ran 50 feet before breaking up and arresting. Photo: J. Taylor
Small isolated wind slab avalanche in the Playground
We triggered a small soft slab avalanche when skinning near the top of Pair Of Chutes in the Playground. The slab was about 1 foot thick, fist hardness, propagated 20 feet wide and ran 50 feet before breaking up and arresting. The slab did not entrain additional snow as it slid. The avalanche hit my feet but did not disturb my balance. However, it could have been dangerous above consequential terrain. Moderate gusting to high winds were sustained the entire day and wind slabs were widespread in the backcountry terrain north of Bridger.
On January 26 we saw a handful (4-6?) of old wind slab avalanches of various ages. The most recent and largest appearing, but still not very fresh, was on the north side of Scotch Bonnet (attached photo). Most were D1-D1.5, the slide pictured was D1.5-2. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Mon Jan 27, 2025
Ride around north of Cooke
We saw most terrain in the motorized area north of Cooke City. We went passed Round Lake to Goose Lake wilderness boundary, around the north of Sheep Mtn. and Scotch Bonnet to Lulu Pass, out to Mt. Abundance, back south over Daisy Pass, and around town hill/Miller Rd., then up and down Sheep Creek to the top.
Skies were clear and wind was calm to non-existent with cold temperatures (singles to teens F).
We saw a handful (4-6?) of old wind slab avalanches of various ages. The most recent and largest appearing, but still not very fresh, was on the north side of Scotch Bonnet (attached photo). Most were D1-D1.5, the slide pictured was D2.
We dug on the southeast shoulder of Mt. Abundance (profile attached). Snow depth was 3.5-4 feet and we had ECTNs. There were some soft-ish facets near the bottom of the snowpack. We also dug a pit in Sheep Creek and had an ECTX, snow depth of 4-5 feet. We did a lot of hand pits to look for recently buried facets. Small sugary facets were generally easy to find, buried 3-6" deep below soft snow. If and where snow is drifted into thicker slabs, these facets might make those slabs more reactive.
A lack of recent avalanches combined with minimal recent loading from new snow and wind point to avalanches being unlikely. The recent large persistent slab in Hayden Creek shows that although slides are unlikely they could be big. We would rule-out big slopes that are heavily wind-loaded, and otherwise feel ok in steep terrain while sticking to safe travel protocols (carry a transceiver, probe AND shovel, and only expose one person at a time to avalanche terrain).