Southern San Juan
SnowpackChris Bilbrey · Apr 21, 2023 · Southern San Juan
Weather
A mix of clouds and sun with cool temperatures. Thicker cloud deck remained to the northwest with periodic pieces of moistures passing overhead. Moderate winds out of the northwest, and brief strong gusts.
Snowpack
The snowpack has fully transitioned into a spring pack around the compass on near and below treeline slopes, and southerly-facing slopes above treeline. Northerly alpine slopes still harbor cold, dry snow. We found subtle effects of prior warming on northeast and northwest aspects, where a thin crust resides in the upper layers. More obvious were hard, wind-layers from the prolonged windy and generally dry weather during April. Neither the wind layers, thin crust, or tiny facets embedded within seem to have much influence on instability. Snowfall over the last couple of days left a skiff of snow below treeline (enough to visually cover the frozen coral reef, but not enough to soften the ride). New snow depths increased to 3 to 4 inches, with drifts around 6 inches deep around 11,400 feet and higher. The distribution of new snow ranged from isolated to specific depending on the slope. Slopes that face north through east are where we found deeper drifts, while west and northwest were mostly scoured from recent winds. Despite firm surfaces below, the new snow has bonded well and was stubborn to sluff with ski pressure on slopes over 35 degrees. By midday, the top 1/2" of the snow surface on southerly, wind-sheltered slopes began to soften. This was generally below 11,000 feet. Open slopes exposed to the wind at similar elevations did not exhibit the same surface softening. Dust emergence is becoming more widespread across aspects favoring those more recently scoured, southerly aspects, and most notably in below treeline areas.