Skiers on 03/29/2024 saw this avalanche on the N face of Hyalite Peak from Divide Cirque. This avalanche likely occurred in the last 24 hours. Photo: E. Webb
23-24
On 03/29/2024 skiers saw this recent avalanche on a NE aspect in the Divide Cirque at 9800'. This likely happened in the last 24 hours. Photo: E. Webb
Forecast link: GNFAC Avalanche Forecast for Sat Mar 30, 2024GNFAC Avalanche Forecast for Mon Apr 1, 2024
Divide Cirque Obvs
Skied Divide Peak this morning. Snowfall totals in the main fork were around 3", while the Shower falls area experienced 6-8". Inconsistent snow depths within divide cirque highlight heavy snow transport yesterday and overnight. Varying levels of sun crust below the most recent snow were widespread.
One hand shear on a solar ESE aspect demonstrated cohesiveness, which seemed to be due to moist snow, on a thick crust. Sheer quality created a pretty smooth bed surface.
Today's tour provided many views of undulating wind effect- cornices on west-east ridges formed on south and north sides. Plenty of large cornices were present and could be quite destructive.
Spotted two fresh natural slides, one within Divide cirque on a NE aspect @ ~9,800 (D1, R1), and another on the N face of Hyalite @ ~10,200ft. that was mostly out of view, but could be estimated around similar size and destructiveness. These seem to have occurred within the last 24 hours, or after snowfall, likely windslabs on lee slopes.
We skied east of the central divide gully, avoiding wind issues to the west and solar issues to the east.
ECT below the Ramp
ECTP 11 30cm down on melt freeze layer.
PST 28/100 End
location: meadow below the ramp above Bradley’s meadow.
Recent natural avalanche on Mt. Blackmore
Spotted this big guy on the east face of Blackmore today. Seemingly natural and I believe it occurred in the last 36 hours or so. Debris had last nights snow on it. I’d estimate it at D2.
GNFAC Avalanche Forecast for Fri Mar 29, 2024
<p><span><span><span><span><span><span>Over the last 36 hours it has snowed 10-16” (1.1-2.0” of </span></span></span></span></span></span><a href="https://avalanche.org/avalanche-encyclopedia/snowpack/snowpack-observat… water equivalent</span></span></u></span></span></span></span></span></a><span><span><span><span><span><span>). Strong winds yesterday drifted this new snow into slabs that will be easily triggered today. Either simply avoid these drifts or check to make sure they’re well bonded to the old snow surface before getting onto steeper slopes. Small, steep test slopes can be a great way to safely assess these surface instabilities (</span></span></span></span></span></span><a href="https://www.mtavalanche.com/images/24/small-skier-triggered-wind-slab">…; of a small windslab I triggered yesterday near Cooke City). Recent avalanches or shooting cracks are clear signs of unstable drifts that mean steep wind-loaded slopes are ready to avalanche. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>These wind slabs could be several feet thick by themselves and plenty dangerous, but would also be a good trigger for huge avalanches breaking on the weak layers at the bottom of the somepack. It’s been a bit since we’ve last seen one of these slides breaking deeper, but the loading over the last week with yesterday’s additional snow on top makes us a bit nervous about the possibility today (</span></span></span></span></span></span><a href="https://www.youtube.com/watch?v=MGZxS-K8u3o"><span><span><span><strong>… Rind video</span></span></u></span></strong></span></span></span></a><span><span><span><span><span><span>). Assessing these deeper weak layers is much more difficult than assessing the surface instabilities. The best management strategy is picking slopes on the lower angled and smaller end of the spectrum with less obstacles or terrain traps beneath them. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>If the sun pops through the clouds, loose wet avalanches will quickly become a concern and with plenty of new snow and crusts beneath it they could be good sized and run far. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Human triggered avalanches are LIKELY and the avalanche danger is CONSIDERABLE.</span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Our concerns are generally similar around Bozeman and Big Sky, but with less new snow wind drifts will be a bit thinner and triggering an avalanche is a bit less likely. On many slopes the wind drifts that formed yesterday will have bonded well to the old snow surface, but be on the lookout for thicker drifts and those that aren’t bonded as well. Be on your toes if the sun pops out as the new snow will quickly become wet and start to sluff on steep terrain. Keep your terrain choices in check as deeper slides also aren’t totally out of the question today. </span></span></span></span></span></span></p>
<p><span><span><span><span><span><span>Remember that even shallow avalanches can be dangerous in the wrong spot (especially above cliffs where just getting knocked off your feet could have big consequences). </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>
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