Northern San Juan
AvalancheAnonymous · Jan 6, 2014 · Northern San Juan
Weather
Clear, 15 mph NNW wind, no precip. about 20F. At treeline on a W,SW ridge of peak 12,603 just southwest of Ohio Peak. Aspect was SSW at approx. 210 degrees. Elevation was 12,000' ** Your N. SJ forecast was spot on for today, thanks! Unfortunately we tested it.
Snowpack
130cm at crown, 38 degrees. Three MF crusts approx. 5cm thick @ 210, 80cm, & 60cm knife hardness , 10 cm of fresh wind deposited snow on top. 4 F density snow between 120 cm and 80. 1F density from 75 to 60, 55 to 25 cm was Pencil hardness. 25-0 cm was facets of approx. 2-4mm. Both obvious slabs did not appear to run on the MF crusts but on thin surface hoar? for the 12" slab whereas the thicker slab seemed to be Persistent? problem and collapsed on facets? and ran to the ground.
Avalanche
Traversing off ridge onto SSW aspect with obvious wind loading onto the slope, minimal cornice build-up. First skier noticed settlement after crossing over ridge onto slope of about 30 degrees. First skier continued across slope toward sub-ridge about 100' distant and noticed settlement again before reaching sub-ridge and safe stopping zone. Second skier had stopped just over ridge on 30 degree slope and waited for 1st skier. When skier 2 continued on about 25', felt settlement & then noticed fracture propagating above and across slope and start to move. Skier 2 then attempted to ski down slope and was caught and partially buried (uphill leg and ski) at the toe of the slide near the left flank. Slide approximately 75 yards wide by 125 yards long. Wind slab and persistent slab from 12" thick to 24" thick. Majority of the slide went to the ground. Slow running slide.