Greetings from Silverton,
On Tuesday, March 22, dust event #3 (D3) began in the afternoon in the San Juan Mountain region. Then (at Senator Beck Study Basin), starting approximately 8 pm that evening, snowfall started covering the newly deposited dust with 13" (33 cm) of clean snow by the following evening.
D3 ensued during the latter portion of the CODOS state-wide sampling tour, where we assess dust-on-snow conditions at 11 locations across Colorado. After D3 occurred, we visited Wolfe Creek Pass, Spring Creek Pass, and our Swamp Angel Study Plot (SASP).
D3 was a mild event at our SASP site. It was a bit more prominent at Wolf Creek Pass, and very much a significant event at the Spring Creek Pass location. Observations at Spring Creek indicate D3 was a dry deposition event at that location as well. Please see photos below.
SASP, March 24, 2016. Mild D3 dust layer under 13" (33 cm) of fresh snow.
Spring Creek Pass, March 23, 2016. At CODOS sample location, D3 is 2"-2.75" (5-7 cm) below the surface. D2 is 2.75" (7 cm) below D3.
Spring Creek Pass, March 23, 2016. High winds scouring new snowfall, keeping D3 exposed in some areas, and creating dust dunes.
Wolf Creek Pass, March 23, 2016. Crust containing D3 and D2 is located approximately 5" (13 cm) below fresh snow accumulation.