22-23
36” total. 24” sugar on bottom.
From Email: It was actually great riding up there. Just no base once you broke through. Definitely solid on top and held weight of the sled.
Snowpack at 8000 ft in pioneers is about 2 feet deep and mostly facets. About a foot of 3 mm large squares on the ground, a slightly more dense 4F- layer of crust and facets and another foot on top of that of soft NSF and new snow. Intentionally triggered a very small test slope, slab failed on the lower facet layer. See pics of quick pit and test slope results. Boot and ski penetration to the ground. Weak.
Forecast link: GNFAC Avalanche Forecast for Fri Dec 30, 2022
Snowpack at 8000 ft in pioneers is about 2 feet deep and mostly facets. About a foot of 3 mm large squares on the ground, a slightly more dense 4F- layer of crust and facets and another foot on top of that of soft NSF and new snow. Intentionally triggered a very small test slope, slab failed on the lower facet layer. See pics of quick pit and test slope results. Boot and ski penetration to the ground. Weak.
Heavy snow but non-reactive on Texas Meadows
Toured up to Texas Meadows yesterday, it was spring-like conditions the whole way. We dug a pit at approximately 7600ft on an east aspect, HS was 114cm, and we got an ECTx. There was 10 to 20cm of weak rounds on the ground, and a layer of weaker snow at about 67cm. Our shovel shear broke on the 67cm layer, but it wasn't planar.
GNFAC Avalanche Forecast for Tue Dec 27, 2022
<p>Dangerous avalanche conditions exist in the mountains around Cooke City and West Yellowstone. Cooke City has received 8” of wet snow in the last 48 hours, with 2” near West Yellowstone. Strong winds from the south to southwest are gusting to 55 mph and blowing snow into unstable drifts at many elevations and aspects that are likely to avalanche. A storm bringing 4-8” of snow during the day will increase the danger on all slopes. In addition, two weak layers buried one foot deep and near the ground make much larger avalanches possible.</p>
<p>Yesterday, a splitboarder riding just outside our advisory area near Cooke City intentionally triggered an avalanche breaking 6-18” deep and saw cracks shooting from the nose of his board (<a href="https://www.mtavalanche.com/node/27341"><strong><span>observation and photos</span></strong></a>). Similar to what Alex and Doug found at Lionhead this weekend (<a href="https://www.youtube.com/watch?v=F8HKebJ_OJA&list=PLXu5151nmAvTi1DBS…;, <a href="https://www.mtavalanche.com/node/27323"><strong><span>observation</span…;), a boarder in Republic Creek confirmed seeing a reactive weak layer buried a foot deep (<a href="https://www.mtavalanche.com/node/27345"><strong><span>observation</span…;).</p>
<p><span>Careful route finding and snowpack evaluation are essential. Avoid all steep, wind-loaded slopes, and expect the danger to increase with today’s snow. The avalanche danger is CONSIDERABLE. </span></p>
<p>The avalanche story is complicated in the Madison, Gallatin and Bridger Ranges where problems including rain and wet snow at lower elevations, new snow during the day, strong winds creating unstable drifts and two weak layers buried a foot deep and near the bottom of the snowpack make avalanches possible.</p>
<p>Yesterday, a skier near Big Sky triggered “whumphing” on a slope indicating unstable weak layers (<a href="https://www.mtavalanche.com/node/27334"><strong><span>observation</span…;). I found a weak layer of near-surface facets buried a foot deep at Mount Blackmore and saw the wind drifting snow (<a href="https://youtu.be/jjrqrzYhpIc"><strong><span>video</span></strong></a>). Another group at Blackmore got unstable results with their test propagating on the near-surface facet layer. Alex confirmed multiple weak layers at Buck Ridge and saw recent avalanches (<a href="https://www.youtube.com/watch?v=C2HXtmgNkt8"><strong><span>video</span>…;). And the Big Sky Ski Patrol noted “very sensitive” slabs of wind-drifted snow 4-6” deep during routine mitigation.</p>
<p>Today, precipitation will begin as rain at lower elevations. Yesterday, on our drive down Hyalite Canyon, we observed small wet snow avalanches on the roadcuts. Any rain will have a destabilizing effect on the snowpack.</p>
<p>Keep your head on a swivel looking for signs of instability because human-triggered avalanches are possible, and the danger is rated MODERATE.</p>
<p><span>Please share avalanche, snowpack or weather observations via our<a href="https://www.mtavalanche.com/node/add/snow_obs"><span> </span></a><a href="https://www.mtavalanche.com/node/add/snow_obs"><strong><span>website</s…;, email (<strong>mtavalanche@gmail.com</strong>), phone (406-587-6984), or Instagram (#gnfacobs). <span><span> </span></span></span></p>
<p><span>Dangerous avalanche conditions exist in the mountains around Strong winds are gusting to 55 mph and blowing snow into unstable drifts at many elevations and aspects that are likely to avalanche. A storm bringing 4-8” of snow during the day will increase the danger on all slopes. Two weak layers buried one foot deep and near the ground make much larger avalanches possible. Today, careful route finding and snowpack evaluation are essential. </span></p>
Upcoming Avalanche Education and Events
Our education calendar is full of awareness lectures and field courses. Check it out: Events and Education Calendar.
Thursday, December 29, 6:30 p.m., Avalanche Presentation and Raffle (great odds of winning!) at MAP Brewing in Bozeman. Free.
Weather and Avalanche Log for Tue Dec 27, 2022
Rain and snow in the north; snow in the south and wind everywhere. Lone Peak measured 105 mph.
Two avalanches on Buck Ridge
We saw two large avalanches in the 2nd Yellow Mule that were probably 2-3 days old, and likely broke on the weak layer near the bottom of the snowpack. Hard slabs on heavily wind-loaded slopes.