GNFAC Avalanche Forecast for Sun Mar 9, 2025
<p><span><span><span><span><span><span>Today the primary avalanche problem is </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> where 5-7” of snow from Thursday was drifted into stiffer slabs. These drifts were reactive and easily triggered the last couple days. Yesterday in the northern Bridgers skiers triggered a few wind slabs that were 8-10” deep and 10-20’ wide. One person was caught and carried ten feet (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34550"><span><span><span><strong><span… and photos</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Two days ago Ian and I found similar fresh drifts that easily cracked under our skis (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/reactive-wind-slabs"><span><span>…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/reactive-wind-slabs-2"><span><spa…;, </span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=Y8xb7L0c0Ug"><span><span><span><strong>…;
<p><span><span><span><span><span><span>Above freezing temperatures and sunny skies will make </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> a concern later in the day. These will probably be small, but could easily knock over a person. Watch and feel for a wet or moist snow surface to indicate you could trigger shallow loose snow slides, and anticipate this hazard to develop mostly around rock outcrops on slopes that receive direct sunshine. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Remain cautious of travel on steep wind-loaded slopes and steep sunny slopes today, especially above cliffs, rocks or thick trees where even a smaller slide would be more dangerous.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Near West Yellowstone and the southern Madison and Gallatin ranges an additional concern is </span></span></span></span></span></span><span><span><span><strong><span><span>Persistent Slab avalanches</span></span></strong></span></span></span><span><span><span><span><span><span> breaking 2-3’ deep on weak layers buried in late January. The last of these deeper avalanches were over a week ago (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/25/wind-loaded-slide-backside-lionhe…;). The likelihood has decreased, but the size would be big enough to have serious consequences. These slides were mostly on mid-elevation slopes with trees around and have surprised riders, leading to several close calls (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34421"><span><span><span><strong><span…;, </span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34413"><span><span><span><strong><span… Creek</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). </span></span></span></span></span></span><span><span><span><span><span><span>Travel one person at a time across steep slopes and have a partner watching from a safe spot. If you ride steeper slopes, choose terrain with minimal trees, rocks, cliffs or confined gullies. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>The avalanche danger is MODERATE.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Cooke City got less new snow last week, so the likelihood and size of potential avalanches is smaller. </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> are a concern, but their size will be small and distribution is minimal. Avalanches breaking deeper on buried weak layers are unlikely. The last of these persistent slab avalanches were a couple weeks ago (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/node/34382"><span><span><span><span><span><…;), and were the only slides of this type near Cooke City over the last couple months.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>While the snowpack is generally stable, you should follow standard safe protocols for travel in avalanche terrain. Expose only one person at a time to steep slopes and carry proper rescue gear (transceiver, probe and shovel). Stay alert for recent drifts and wet loose avalanches, especially in terrain where a small slide has higher consequences. </span></span></span></span></span></span><span><span><span><span><span><span>The avalanche danger is LOW near Cooke City.</span></span></span></span></span></span></p>
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Skier triggered Wind Slab Avalanches in Frazier Basin
From obs: "Skier triggered wind slab on Northeast slope at 7,450 feet elevation. One skier was caught and carried roughly 10 feet before the slide came to a stop."
We also received reports from another group (IG story video) that triggered a couple similar sized wind slab avalanches in north facing chutes in Frazier Basin.
Skier triggered wind slab on Northeast slope at 7,450 feet elevation. One skier was caught and carried roughly 10 feet before the slide came to a stop.
Forecast link: GNFAC Avalanche Forecast for Sun Mar 9, 2025
Skier triggered wind slab on Northeast slope at 7,450 feet elevation. One skier was caught and carried roughly 10 feet before the slide came to a stop.
Skier triggered wind slab on Northeast slope at 7,450 feet elevation. One skier was caught and carried roughly 10 feet before the slide came to a stop.
small loose snow slides N. Bridgers
The new snow was low density and sluffed easily on steep shady northerlies. On steep slopes facing the sun (south and east, and probably west) the new snow sat on a crust and became moist as the sun warmed it up and started to slide under skis. We saw a couple very small natural loose snow slides below rock outcrops on south facing slopes. Air temperatures were well below freezing, especially with wind chill, but the sun quickly warmed the recent new snow.
Fresh reactive wind slabs N. Bridgers
There was 6" of low density snow from yesterday. Winds were stronger than expected, from the north at the top of the Throne, and increased through the morning.
We found fresh drifts that were reactive, cracking easily and 5-10' wide out from our skis, on south and east facing slopes around 8000-8300'.
Shooting cracks in wind slab north of Cooke
From obs: "We found up to a 6” deep wind slab producing shooting cracks at Goose Lake on a NW facing slope at 10500ft."