Southern San Juan
SnowpackChris Bilbrey · Apr 11, 2023 · Southern San Juan
Weather
Another hot, sunny day with only a flick of wind at higher elevations.
Snowpack
Monday night's weak freeze left an egg-shell cover over the snowpack. The surface refroze just enough to be supportive to skis, but we could punch past boot tops (approx. 30 cm) on sunny slopes below treeline around 10 AM. As we moved up in elevation, boot penetration decreased to between 15 and 20 cm above treeline on easterly-facing slopes, and 5 to 10 cm on northerlies. The snowpack on sunny slopes near trees or exposed rocks was noticeably weaker and we easily sunk deeper into wet snow. Avoiding traveling on or below steep slopes with wet snow was an important terrain management objective for us, and we found safer travel along the ridgeline - giving larger cornices an extra buffer. Our snowpit on an east-facing slope at treeline revealed two wet, melt form layers near the surface (32 and 50 cm down). The upper layer did not fail in snowpack tests, but the lower one produced CT RP 15/16, and ECTP 22. The melt form grains were 1 to 2 mm sized. The slab in-between the two layers ranged P- to 1F, and the slab below the lowest layer was mostly P hard. Traveling across a large, flat opening around 3 PM, we observed numerous long-propagating surface cracks with some running up into steeper slopes, but those slope angles only increased to near 30 degrees. All in all, a hot day in the mountains with wet snow expanded to new aspects/ elevations. Below 10,000 feet in the afternoon, the snowpack had turned to junk, but had not transitioned to full-depth trap door conditions.