Public Observation #2022-889
Submitted:December 12, 2022 9:21 AM
Observation Date:December 11, 2022
Zone or Region:Central Cascades
Did you observe any avalanches?Yes
Avalanche Type:Hard Slab
Size:D2: Could bury, injure, or kill a person
Comments:We observed what looked to be a slide path from the previous day or two. The crown appear to be about 2 feet deep, and it had started from around 7200 feet and propagated 75-100 yards wide across a complex slope. It did not appear to have broken to the ground, so this may have run on a layer of buried surface hoar.
Signs of Unstable Snow
Did you see shooting cracks?Yes
Did you experience collapsing or whumpfing?Yes
ObservationsWe dug a pit on a north facing aspect at about 6,900 feet. I did a poor job of taking precise measurements and photos, but snow depth was about 140-150cm. We found what looked to be a layer of buried surface hoar about 60-70cm down. We also found about ~10cm of loose ground facets at the bottom of the snowpack. The snowpack in this zone was sitting on scree. Snow density was 1-2 finger above the facets and progressed evenly to fist hardness at the top of the snowpack, aside from the BSH layer.
Later while skinning through the area above the slope on which we dug the pit, we felt a collapse and observed a crack running horizontally along the entire slope we were skinning on. We were in a safe location, but the slope was connected to a mid-30 degree slope below us.