Professional Observation

Observation Details

Signs of Unstable Snow

Drove 395 N today from the Southern Sierra to Mammoth this morning. The sun was out all the way to Bishop allowing good views of the mountains. Blowing snow from SW wind was observed all along the Sierra Crest, being quite intense at the high, crest level elevations, but also evident on mid-slope features.

It was a fantastic day for viewing lingering evidence of avalanches from the most recent storms. Some of the avalanches we saw were obviously fresh with crown lines visible and obvious debris, others more muted by new snow. Many slides seemed to have begun as dry slab avalanches and entrained much moist/and or wet snow on their way down creating large, dense debris piles. We saw slides up to what appeared to be size D2.5-3 in some locations. We saw slides with large, open, leeward starting zones  facing N, NE and E, with obvious crowns indicating initial wind slabs; and some that originated in mid-slope, lower elevation areas that were steep and rocky, generally facing more East and receiving strong sun.

A few photos of slides between Mammoth and Bishop: