Northern San Juan
AvalanchePatrick Ormond · Feb 19, 2018 · Northern San Juan
Weather
2/17/18: Clear skies, light-mod WSW winds. No precip. 2/18/18: Few clouds am, broken skies pm. Mod-Strong SW winds, mod-intense blowing snow. No precip. 2/19/18: broken-overcast skies. Strong-Extreme SW winds. Intense blowing snow. Snowing S1-2 all day. HN24 8-10cm by 12pm. Dropping temps over the 3 days.
Snowpack
Highly variable. Much wind effect ATL, with drifting, scouring, wind slab, wind crust/board. Solar aspects TL/BTL developed thin crust. Few collapses noted, mostly localized and not widespread. Minor cracking in fresh wind drifts TL/BTL 2/19. Low angle terrain so nothing went anywhere.
Avalanche
Natural cycle during the night or early morning 2/18. Debris seen in Spirit Gulch from North facing aspect. Slab with sympathetic slab seen from afar in North facing Paradise Basin off Ophir Pass road. Both avalanches seem likely from cornice failure/wind loading with strong SW winds.