Close
Eastern Sierra Avalanche Center

Professional Observation

       

Basic Information

Observation Details

Observation Date:
February 27, 2023
Submitted:
February 27, 2023
Observer:
Barbara Wanner | Key Observer
Zone or Region:
Lee Vining
Location:
Many slides in unusual places in the Mono Basin

Signs of Unstable Snow

Recent Avalanches? 
Yes
Cracking? 
None Experienced
Collapsing? 
None Experienced

I finally got some visibility yesterday morning (February 26th). Went to check out what the new snow and winds from the February 24 – 26th storm resulted in.

  • Many small to large avalanches ran in drainages and on slopes with a NE aspect above Mono Lake.
  • Several of these slab avalanches ran at low elevation with a mid slope crown line at a slight convexity. Their debris spilled onto Hwy 395 resulting in road closures including one that ran late afternoon yesterday.
  • Some slides started up higher where new snow and continued wind-loading was overburdening the start zones.
  • My guess is that some of the low elevation slab avalanches ran on the weak pre-strom snow surface of rime and surface hoar that built up like a bathtub ring around the Mono Basin during extended periods of valley fog aka Poconip.

Snow Stability

Stability Rating: 
Very Poor
Confidence in Rating: 
Stability Trend: 
Worsening

Advanced Information

Avalanche Observations

Close