Quick report
A party submitted photos of an avalanche on 12/29 on the N side of the Sisters that looked suspiciously like a persistent slab avalanche. We decided to head out there to get more details. We discovered a second avalanche and confirmed that both were persistent slab avalanches. We also confirmed that they were both more than ten days old - likely they occurred on 12/20/23. For more information, check out this avalanche observation.
As for today, we saw variable snow surfaces, including 1-3 inches of soft snow on supportable crusts, exposed icy crusts, wind-scoured and sculpted surfaces, and small pockets of wind-drifted snow. Bushes and rocks still poke through the snowpack in many areas, but coverage above 8800 ft was pretty good. We did not see any obvious signs of instability today.
Weather
- Air Temp
- 23
- Cloud Cover
- overcast
- Wind Loading
- light
- Snow Avail For Transport
- small smounts
Cold and overcast weather prevailed during our tour. The winds mostly remained light, but some of the gusts did transport small amounts of snow.
Snowpack
The snowpack structure consisted of a cohesive mid-pack on top of old, weak snow. Snowpit tests indicated that while the old, weak layers still exist, they seemed to have gone dormant.