Northern San Juan
AvalancheColin Mitchell · Apr 6, 2020 · Northern San Juan
Weather
Warm and breezy morning. Temperatures rose quickly after daybreak, and reached 40 degrees by the time of my arrival, accompanied by light and gusty southwest winds.
Snowpack
Wet! Water has penetrated to within a few centimeters of the ground here, evidenced by obvious melt-water effects on snow grains and percolation columns. My profile was in the deepest part of the snowpack on this slope. Although it was 165 cm where I dug, average HS on this slope is around a meter. This deeper area is the only reasonable location for profiles. The upper half of the snowpack has been completely saturated, the effects of melting were less pronounced lower down, but still obvious. The bottom 20 cm was moist, rounding facets. The facet/crust layers formed in late February are now buried by about 50 cm of snow from March and early April. This faceted layer produced hard propagating results (ECTP27) on March 22. It has been weakened by melt water. Today, I got ECTP14 and ECTP18 on this layer. The failures were of the sudden, vigorous 'pop and drop' variety. Overall, we are getting close to having a uniform, isothermal snowpack here, but not there yet. The forecast cooler weather starting on Thursday should help stabilize things.
Avalanche
No activity observed today anywhere in the corridor or surrounding terrain south of Silverton.