Dust on Snow Update

Water Year 2010 has already distinguished itself from Water Year 2009 by the absence of dust-on-snow events, to-date. By March 1, 2009 there were three dust-on-snow events in the western San Juan Mountains. So far this season, however, we have observed only one dust-on-snow event. The October 27, 2009 dust  layer, although it deposited a significant amount of dust on the then-shallow snowpack, did not initiate a significant snowmelt surge and will not play a major role in Spring 2010 snowmelt.