GNFAC Avalanche Forecast for Sun Apr 6, 2025
<p><span><span><span><span><span><span>Today the two main avalanche problems you might encounter are </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> and </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>. Yesterday in the Bridger Range, wind slab avalanches were triggered by skiers (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34844"><span><span><span><strong><span… Peak</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34845"><span><span><span><strong><span… Great One</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>), and some loose snow avalanches ran naturally (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/natural-loose-slides-bridge-ridge…;). I had similar </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34848"><span><span><span><strong><span…; near Cooke City where wind slabs were notably more reactive than expected, despite having had some time to stabilize since snowfall tapered off a couple days ago.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Don’t trust old drifts today, and expect any fresh drifts to be easy to trigger. These wind slabs are relatively small, but can easily knock you over and be harmful if they carry you into rocks, over a cliff, or down a long steep slope. A textured or rounded snow surface is a sign the snow has been drifted into a stiffer slab. Be cautious of wind-loaded slopes, especially in terrain where being carried in even a small slide would have high consequences.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>As sunshine and above freezing temperatures melt the snow surface, wet loose avalanches will become possible to trigger and some may run naturally. Soft snow from last week is sitting on firm crusts which could cause wet loose slides to be pretty big and run far. Temperatures are starting warmer and will be higher than yesterday which will probably cause the snowpack to lose strength earlier in the day, and get wet deeper into the snowpack and on slopes that remained dry yesterday.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Expect the snow surface to get weaker through the day, especially on slopes that receive direct sunshine. Sunny slopes will have a crust this morning. Plan to be off steep slopes before the crust melts or the surface gets wet. Moist sticky snow or roller-balls on the surface mean it is time to find lower angle terrain or slopes with colder, dry snow on the surface.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The sunshine and heat will also make </span></span></span></span></span></span><span><span><span><strong><span><span>cornice falls</span></span></strong></span></span></span><span><span><span><span><span><span> possible. Along ridgelines, overhanging drifts of snow have become large. As these cornices melt and lose strength they could break naturally or under the weight of a person. Minimize your time on slopes below cornices and stay far back from the edge while travelling on ridgelines above them.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is MODERATE across the forecast area.</span></span></span></span></span></span></p>
natural loose snow slides in Bridgers
Observed multiple D1-1.5 natural dry loose avalanches (and some tiny wind slab pockets under the ridge cornice) that likely occurred during peak warming around 2-3 PM. North/sheltered aspects from ~9- 8.5k held an average of 8+ inches of dry, drifted snow. Early AM to mid-afternoon, very active wind transport followed by tapered winds and a rapid increase in temp.
Natural wind slabs and loose snow near Cooke
We saw a couple 3-6" deep natural wind slab avalanches and a few dry loose slides that looked to have happened within the last 24 hours. On southerly slopes below 9,000' there were some wet loose slides from yesterday afternoon.
Reactive wind slabs near Cooke City
Apr 5 Wind slabs were still reactive. We triggered 3 small, 3-8" deep x 5-15' wide, hard wind (1F+) slabs on convex test slopes well below the main ridgelines. 9,800', NE aspects. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Sun Apr 6, 2025GNFAC Avalanche Forecast for Mon Apr 7, 2025
Apr 5 Wind slabs were still reactive. We triggered 3 small, 3-8" deep x 5-15' wide, hard wind (1F+) slabs on convex test slopes well below the main ridgelines. 9,800', NE aspects. Also triggered one softer (4F) wind slab just below the high ridgeline, 10,200', NE aspect. 10-15' wide x 6-8" deep (Pictured). Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Mon Apr 7, 2025
Apr 5 We saw a couple 3-6" deep natural wind slab avalanches and a few dry loose slides that looked to have happened within the last 24 hours. Photo: GNFAC
Forecast link: GNFAC Avalanche Forecast for Sun Apr 6, 2025
Skier carried in wind slab on Naya Nuki
We went on a tour in the Bridgers today, we ascended the east ridge of Naya Nuki to the entrance of the Great One. Wind was blowing and we were being careful about potential wind slabs up high.
Skier 1 ski cut the top of the chute and produced a small wind slab that ran to the break in the chute and continued another 100 vert down the east apron. After all meeting up halfway down, skier 2 proceeded to ski the E facing apron. A wind slab propagated and carried skier 2 roughly 300 vert down the apron where skier 2 was able to swim out of the fall line and came to a rest on top of the debris. Everyone was okay aside two missing ski poles.
On the way out, we saw a few more small natural wind slabs that broke naturally near ridge lines as well as point and release wet slides.
"We went on a tour in the Bridgers today [Apr 5], we ascended the east ridge of Naya Nuki to the entrance of the Great One. Wind was blowing and we were being careful about potential wind slabs up high.
Forecast link: GNFAC Avalanche Forecast for Sun Apr 6, 2025
Snowboarder triggered wet loose slide in Bridgers
A snowobarder tagged us in an IG story of triggering a long running, powerful wet loose slide in the Bridger Range.