Southern San Juan
AvalancheJeff Davis Chris Bilbrey · Mar 19, 2021 · Southern San Juan
Weather
Splitter San Juan day. Ample sunshine, light winds and warm temperatures.
Snowpack
The biggest change or hazard we observed in the snowpack today was driven by warm ambient air temperatures and sunshine. Looking at local weather stations, temperatures were north of the freezing mark above 12,000 feet for over ~7 hours starring around 10 am and were finally dropping around 5 pm when clouds moved into the area. Last night's clear skies contributed to strong radiational cooling that allowed the snow surface to refreeze on east through south to west-facing slopes near and below treeline. Surface crust quickly broke down by mid-morning but remained supportable to skis. Boot penetration around 30 cm's on easterly-facing slopes. Surface softening and wetting more pronounced on steeper slopes affected by the sun versus flat terrain. Northerly-facing slopes at upper elevations continue to hold dry snow, but those same aspects became sticky and wet below treeline in the afternoon. Wind-drifted slabs in the alpine on northwest through north to northeast aspects were soft and showed good bonding with underlying snow layers. No surface cracks in deeper drifts and ski pressure did not dislodge any wind-drifted pockets below ridges or in cross-loaded terrain features. Rollerballs and pinwheels were widespread in the afternoon with the most activity below rocky outcrops and cliff bands on southeast through south to west-facing slopes.
Avalanche
Widespread Loose Wet avalanche activity on sunny slopes in the afternoon. All small in size and stated as point releases.