24-25
We went through Flanders' Creek to the Flanders Weather Station to pull it for the season. We descended to the Grotto Falls TH via the Winter Dance Route. The surface snow got wet as the day progressed, but we saw no wet snow avalanche activity. I wouldn't be surprised if there was limited activity as the day progressed.
Blazing April Sun
We went through Flanders' Creek to the Flanders Weather Station to pull it for the season. We descended to the Grotto Falls TH via the Winter Dance Route. The surface snow got wet as the day progressed, but we saw no wet snow avalanche activity. I wouldn't be surprised if there was limited activity as the day progressed.
Recent warm temperatures have almost universally affected snow surfaces. North-facing slopes above 9500' elevation remain dry, and pockets of dry snow exist at lower elevations on shaded slopes. South-facing slopes have cycled a few times, and the corn snow is coming in reasonably well.
There were no signs of dry snow instability.
GNFAC Avalanche Forecast for Tue Apr 15, 2025
<p><span><span><span><span><span><span>In Cooke City, fresh snow from the weekend experienced its first significant warm-up with above-freezing temperatures and intense April sunshine yesterday. Similar weather today will repeat the cycle. </span></span></span></span></span></span><span><span><span><strong><span><span>Wet loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span>, both natural and human-triggered, are likely on steep, south-facing slopes. These avalanches typically begin at a point and expand as they collect snow. Rocks and cliff bands often serve as their starting points. Steep, confined terrain poses the greatest risk because snow running downhill has limited room to spread out. Thankfully, wet snow hazards are easy to identify and avoid. Transition to cooler, shaded north-facing slopes before the day’s warmth destabilizes the snow. Conditions are becoming unstable when the upper few inches of snow get moist, roller balls trickle downslope and small wet snow avalanches dribble out of rocky areas.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Over the weekend, strong winds created snow drifts up to two feet thick. While these wind-loaded slopes stabilize relatively quickly, human-triggered </span></span></span></span></span></span><span><span><span><strong><span><span>wind slab avalanches </span></span></strong></span></span></span><span><span><span><span><span><span>remain possible, especially in high elevation terrain where the surface snow remains dry and cool. Either avoid obviously wind-loaded slopes or assess their stability by watching for shooting cracks and performing a quick extended column test - you only need to dig down to the thick underlying crust, 1-2 feet deep (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=sqn0KFZqXYs&list=PLXu5151nmAvSpq8Ps… to video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger in Cooke City is MODERATE.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Temperatures in the Bridger, Madison, Gallatin, Lionhead and Centennial Ranges will reach the mid-50s F. The primary concern is </span></span></span></span></span></span><span><span><span><strong><span><span>wet loose avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> this afternoon, and the focal point for instability is steep rocky slopes with uncompacted snow on southerly aspects (southeast through west). Wet loose slides are mostly a hazard in very steep or extreme terrain, where they could push a skier or rider into obstacles or terrain traps. If you notice pinwheels of snow rolling downhill or small wet slides, move to cooler, shaded northerly aspects to reduce exposure.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Stay situationally aware when traveling </span></span></span></span></span></span><span><span><span><strong><span><span>above and below large overhanging cornices,</span></span></strong></span></span></span><span><span><span><span><span><span> as they tend to break off periodically during warm spring days. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Other than small wet snow avalanches on sun-exposed slopes, the snowpack is generally stable, and dry snow avalanches are unlikely. The danger is LOW and will rise to MODERATE on the specific slopes where snow surfaces get wet.</span></span></span></span></span></span></p>
Weather and Avalanche Log for Tue Apr 15, 2025
Temps: 30 degrees F +/-
Fisher 18 F
Stable, variable snowpack in N. Bridgers
We found soft snow on north-facing terrain in Sac Bowl and off Pomp Peak, skiing until about 2 p.m. on 4/14. The recent storm winds stripped some southeast facing terrain down to crust, but had deposited 4-6 inches of creamy pow in sheltered N zones. Skiing was mostly bomber, with the exception of some wind slab we avoided on a start zone immediately below ridgeline in Sac Bowl. Saw a few small dry loose / point release slides in southern Bridgers, but nothing in N. Bridgers except for old debris piles.
GNFAC Avalanche Forecast for Mon Apr 14, 2025
<p>Today, the 10” of recent snow in Cooke City will get hit by above-freezing temperatures and the powerful April sun for the first time. Natural and human-triggered <strong>wet loose avalanches are likely </strong>on steep slopes facing the southern half of the compass rose.<strong> </strong>These will start narrowly at a point and spread as they entrain this weekend’s snow. Rocks and cliff bands are common areas for these slides to start, and the underlying crusts make for slick sliding surfaces. These avalanches are most dangerous in steep and confined terrain where they don’t have room to spread out. Move to shadier and cooler north-facing aspects before the day’s warmth melts the surface snow. Cinnamon roll-like roller balls and small wet snow avalanches indicate that slopes are destabilizing rapidly.</p>
<p>Yesterday, ski guides in Cooke City noted numerous natural <strong>wind slab avalanches</strong> running long distances (<a href="https://www.mtavalanche.com/node/34907"><strong><span>observation</span…;). Strong winds during the weekend’s storm drifted snow into slabs two feet thick. Wind-loaded slopes are stabilizing, but some will still release under the weight of a skier or rider. Find better snow quality and safer conditions by looking for more sheltered terrain and avoiding the most heavily wind-loaded slopes below cornices.</p>
<p>Assess the stability of recent snow before considering skiing and riding steep terrain by watching for a moistening of the snow surface, obvious signs of instability and performing a quick extended column test down to the crust buried one to two feet deep.<span> </span></p>
<p><span>The danger in Cooke City is MODERATE for dry snow avalanches and will rise to CONSIDERABLE for wet snow slides.<span> </span></span></p>
<p>Cold temperatures refroze the snowpack and will delay the onset of wet snow instability in the Bridger, Gallatin, Madison, Lionhead and Centennial Ranges. As the day warms and the sun hits this weekend’s snow, there will be a few small <strong>wet loose avalanches</strong>, especially on rocky, south-facing slopes. With only a few inches of recent snow, these avalanches will only be a problem in very steep or extreme terrain where they could sweep a skier or rider off their feet, into obstacles and terrain traps. Redirect to cooler, northerly aspects if you observe pinwheels and small wet slides. Wet loose avalanches will be more significant in isolated areas in the upper reaches of the Northern Gallatin Range (<a href="https://www.mtavalanche.com/weather/stations/shower-falls-snotel-site">… Falls SNOTEL</span></strong></a>), where more snow fell in the last few days.</p>
<p>Outside of very steep and extreme slopes with southern aspects, the snowpack is generally stable, and avalanches are unlikely. The avalanche danger is LOW.</p>