Dust storms speed snowmelt in the US West
An unusually high number of the storms has left a film of dust on the Rocky Mountain snowpack, causing it to melt earlier and forcing farmers to adjust. This could be the new normal, scientists say. 
By Nicholas Riccardi
Reporting from Denver — A series of unusual spring dust storms has left the snowcapped mountains of western Colorado stained brown and red, even a bit pink. The dust is speeding up the runoff to rivers that supply millions of people with water and raising fears of an increasingly arid West. Twelve dust storms barreled into the southern Rockies from the deserts of Arizona, Utah and New Mexico so far this year. In contrast, four storms hit the mountains all year long in 2003. Eight occurred in each of the last three years. … The storms leave a dark film on snow that melts it faster by hastening its absorption of the sun’s energy. That, coupled with unseasonably warm temperatures, has sped up the runoff here, swelling rivers to near flood stage, threatening to make reservoirs overflow and fueling fears that there will not be enough water left for late-summer crops. … Painter has found that dust can speed up snowmelt by as much as 35 days — in other words, snow that would normally disappear by May 15 would instead be gone by April 10. … “This is really the story of the wholesale transformation of the West,” Painter said. …
