Vail & Summit County
SnowpackDrew Gibson · Jan 29, 2024 · Vail & Summit County
Weather
Overcast in the morning and mid-day. Temperatures in the high 20s at the trailhead. No wind. There was uninterrupted sun in the afternoon as skies cleared.
Snowpack
The slab on the west aspect is alive and well below and near treeline. It is supportive to skis and difficult to cause a failure in. Even when I dug the tail of my ski in to cause a progressive failure, collapses were not heard until I was at about 11,000ft. While traveling on the skin track I caused multiple collapses as well as when I stepped off the track and trees would shake ~40m away. Test pits showed easy (<10 taps) compression scores and ECT scores a bit higher (~15) failing on the facets under the slab. The weak layer (~30cm of depth hoar) is very weak and often fell out of the pit wall during excavation. Propagation Saw Test scores are holding consistent in the 30/100 range telling me that though the the slab is becoming more stubborn, the weak layer isn't getting any stronger. See the attached pit, the structure was fairly consistent in sheltered BTL and NTL terrain. Surface hoar growth was 4mm-6mm tall up to 12,000ft On NE-facing slopes near treeline the snowpack is deeper, (still less than 1.5m in many places) but the slab is acting similarly to other aspects. I observed two avalanches on northeast-facing slopes. One was at 11,600ft on a small, sheltered, 38-degree rollover. SS-N-R3-D1.5. The slide ran into tight timber and debris stacked up multiple feet. This likely ran last week. The other avalanche was at 11,800ft on an open, wind-affected slope. This slide may have been remotely triggered based on a few other tracks in the area, but it is unknown. SS-U-R3-D1.5