Professional Observation

Observation Details

Signs of Unstable Snow

Snow Stability

Key Points

• Observations from the drive from Bishop to Mammoth this morning showed thin cloudy conditions with likely minimal snowfall amounts at the highest elevations of Mt Tom et al. with ever-decreasing snow coverage in the lower elevations of the Buttermilks. Looks like spring season is going to be short to non-existent outside of Bishop if we don’t get substantial snow fall soon. Solar aspects are primarily dirt and rock now. A block head wind hit the truck slowing progress by the Mammoth airport with white out conditions developing as I headed up 203 into Mammoth Lakes.
• Quite cold, but invigorating this morning with the thermometer registering 10degF @ 9300ft @ 12pm and 7degF @ 10000ft @ 1pm. With the sustained 50-60mph winds on top of the Sherwin Ridge I believe the windchill measured in the realm of -17 to -20degF.
• On average, the height of new snow (HN)=5cm with upwards of 10cm in northerly wind loaded depressions and tree wells. The deepest depths of wind loaded snow I found were along Old Mammoth Road and Red Fir street where winds had deposited over 15cm of snow along road cuts.
• With the cold temperatures the new snow was light and easily sluffed off of steeper aspects, but with such minimal deposition, I could not get anything to run close to even being called a loose-dry avalanche, at least at this time of day. A couple meters down slope was all the snow was running, even on 40deg+ terrain.
• It was lightly snowing most of the morning (S-1) with a few periods of higher intensity under completely overcast skies in the Mammoth area. Mammoth and north was primarily socked in while by Convict Lake to the south the highest elevations were obscured with light cloud drifting below tree line with the intense winds.
• Skinning was arduous with the new light coating of snow over riding firm windboard and temperature crusts. I utilized ski crampons all the way from Mammoth Rock to the top and it took much more time than usual to make the ascent.
• Amazing how much snow we have lost even on the northerly aspects on the Sherwins, cornice lines are gone and snowpack has shrunk, I measured 13ocm total snow @ 9300ft on a due North aspect in sheltered trees.
• Skiing was not that bad where the new light layer of snow was resting on 5-10cm of near surface faceted snow. Otherwise it was classic “Dust on Crust” conditions.
• I could not find any wind slab development along the Northerly aspects adjacent to ridge line from above Mammoth Rock over to the feature called “the Hose”.
• A bit miserable on top and I had to put a buff on which is a rarity for me, I could feel the onset of wind nip along my cheeks and nose today.