Northern San Juan
AvalancheSusan Hale Josh Hirshberg · Feb 25, 2014 · Northern San Juan
Weather
Benign mild day today. Mostly clear and warm with slightest WNW breeze.
Snowpack
Of note are the warm surfaces. Found moist snow as deep as 10-15 cm on most westerly aspects that we traveled on. Even lower angle terrain was seeing the affects of warming. This will ultimately become the next crust interface for our next round of snow. Also of note is the dramatic difference in snow coverage between East-facing slopes and West-facing slopes. Easterlys (NE-E-SE) appear fat/loaded and smooth; while Westerlies near & above TL are virtually stripped, rough with sustrugi or with only pockets of snow coverage. Found HS of 145cm @ 11,500ft on a shaded W slope.
Avalanche
Observed two avalanches today: The previously reported snowmobile triggered slide in US Basin; and two unreported natural release out of Bullion King area (details below). We chose not to approach the NE facing slide in US Basin - due to threats from above - a large, steep, wind-loaded feature topped with a very impressive cornice suspended from the upper cliff. This terrain gains volume very efficiently from SW-W-NW winds and can often be a repeat offender in active winters.