Gunnison
AvalancheCBAC Staff · Dec 29, 2024 · Gunnison
Weather
About 5" of dense snow/graupel overnight. Cloud cover was variable, changing from overcast to partly cloudy back to overcast. Calm winds this morning with some light drifting observed after 2:30 p.m. off of the high peaks. Unusual layer of dense snow capping the snow surface which may or may not limit transport tomorrow with increasing winds; there is lower density snow below that would drift easily if the cap is removed.
Snowpack
We triggered numerous rumbling collapses that would cross terrain features up to 1000' or more. The collapses often required some effort: either hard stomps or the 5th or 7th person to skin past a thin spot. Several of the collapses rattled out persistent slabs from relatively small terrain features. There was about 5" or 6" of very dense new snow (including graupel and occasional rime crusts) that produced minor cracking and ECTP results in stability tests, suggesting a thin storm slab problem today. However, that problem paled in comparison to the persistent slab issue, which has settled and stiffened to about 50 cm thick with 4F. Ski pen is about 4" to 6" now, not directly to the weak layer like it was a the last few days. We did a couple of hasty tests on steeper southerly aspects to see how the new snow was bonding to the thicker crusts there and didn't see any notable results. On lower angle southerly aspects, we got collapses because the crust was thinner and collapsible, and in one case, a collapse traveled over to a northeast facing slope and triggered a couple of remote slides.
Avalanche
Good vis today! Many natural avalanches up to D2 in size ran during the past few days. The natural cycle paused today but human triggering (almost all remote) continued. The terrain where we highlighted facet sluffs last week was most active in the last few days: west, north, and east aspects near and below treeline. Areas like Climax Chutes and Schuylkill Ridge saw extensive activity. Above treeline terrain was quieter but there were a handful of large avalanches. I only saw a few avalanches on southerly aspects; they were on SE aspects above treeline on Bichmond and Augusta.