Northern San Juan
AvalancheChris Bilbrey · Apr 18, 2024 · Northern San Juan
Weather
Bluebird to start, then broken skies (cumulus clouds) moved overhead late-morning and dominated the day. No precipitation, but we observed a brown haze to the southwest over the desert. Fortunately, it didn't look like it was headed our way. Steady westerly wind kept air temperatures cool up high and snow surfaces in check. Temperatures warmed nicely in sheltered areas and at lower elevations.
Snowpack
Monday night's storm delivered about 2 to 3 inches of new snow. Several days later, this was difficult to discern with certainty, but more evident on northerly aspects near and above treeline. The snow surface on easterly, southerly, and westerly slopes that sees direct sunshine looked more like a "caramel-vanilla swirl" than an all white pallet - widespread dust emergence across all elevations. Consecutive nights of below freezing temperatures has helped lock-up the upper snowpack and we found firm, supportive conditions to start the day. As things warmed, boot penetration increased. This ranged 20 to 30 cm below 11,000 feet to only three or four inches above that to the treeline. In the alpine, surface softening was only an inch or two. All aspects below about 11,500 feet had a moist to wet snow surface, and slightly "less-wet" grains below to about a foot deep on due north aspects. If we return to a prolonged period of non-freezing conditions, northerly aspects near and maybe below treeline could come into play for wet snow activity - more of the human-triggering flavor. Higher elevation north-facing slopes are about the only spot to find colder, drier snow. However, the warmth is taking its toll on conditions and we found evidence of moistening grains below the surface in isolated, higher elevation spots. As we descended lower in elevation during the afternoon, the snow surface got really wet and sticky. All in all, we did not encounter lots of "trap-door" conditions from today's warming and the snowpack looks tired and unlikely to produce a wet snow avalanche the lower you move in elevation. We did not find continuous enough snow cover for skinning till we climbed to around 9,300 feet from town.
Avalanche
Pretty quiet on the wet snow avalanche front during the big warm-up (4/9-14) and the last few days. Across the landscape, most action was small and of the loose flavor.