Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Bottom Line

This week teaching a Rec level-one avalanche course at Lolo Pass, we observed isolated signs of instability. On the north and northwest aspects, persistent weak layers like buried surface hoar can be found 16 inches down (40cm). We had propagation in our extended column tests and sudden planer brakes in our compression tests on this buried surface hoar layer.
On solar south and southwest aspects, the buried surface hoar layer can be still be found but has high spatial variability and is not propagating in extended column tests. In the heat of the day, we spotted small loose wet slides that had come off large boulders steep hillsides above road cuts and drainages around 5500 feet on southwest aspects.