Professional Observation

Observation Details

Signs of Unstable Snow

A few D.5 loose dry point releases had slid from the northerly cliffs likely during the extreme 100mph+ winds on Monday.

Minor cracking on a few cross-loaded wind ribbons, cracks did not extend greater than 1-2feet and were not of concern here.

Snow Stability

Key Points

• The Mammoth lakes Basin and Mammoth crest were pretty well socked in all morning until the clouds started breaking around noon. It continued to snow all morning with periods of decent intensity, but overall rates were around (S-1)– less than 1cm/hour.
• It was indeed cold as it registered 0degF @ 12pm @ 10,800ft and with the 30mph north wind…wind chill values were around -26degF. It felt good though to feel winter and I relished it.
• New snow depths averaged around 2-4inches until I got above 9500ft within the undulating terrain and sheltered basins below TJ bowl. New snow depths here dramatically increased and on average there was from 8-12” of new light powdery snow in a beautiful blanket reaching up to the tilted cliff bands of the Mammoth crest.
• Steeper (40deg+) tilted northerly terrain around 11000ft in the couloirs was already piped by the northerly winds and for the most part stripped of the new snow.
• The new snow was very light and I did not find any slab in the area during my travels which lasted until 230pm or so. There were some minor cross-loaded ribbons at the mouth of couloirs as well as a few areas of loaded sidewalls above 10500ft, but they did not exhibit any significant cracking or hardened slab. These wind drifts were of Fist Hardness and did not move under kick turn tests, stomping or hard ski cuts. This could be a different situation tomorrow after settlement, wind and increasing temps.
• The new snow was bonded well to old surfaces and I could not find areas where I could isolate a surface block, the new snow was light and un-cohesive. Therefore, I did not bother digging a snow pit. The solidified pack under the Crest is more than robust enough to hold up this new light storm. Snow on steeper terrain that was not affected by the north wind exhibited a bit of sluffing but nothing ran more than a few feet off of turns.
• I have to say it was beautiful day to see the landscape cloaked in a winter shroud again after such a lengthy high and dry period.