Halfway Through Season, Snowpack in U.S. West Thins

An animation showing snowpack in the western United States compares conditions at the end of January, 2011 and this year. (Maps: NOAA NOHRSC; Animation: Tom Yulsman) January was not kind to snowpack in the mountains of the U.S. West — from which most residents of this part of the country derive their water. This week is about the half-way mark for snow season in the West, and scientists have fanned out throughout the region to measure the amount of water locked in snow — a measure called "snow water equivalent." This is a monthly ground-truthing exercise to back up an automated monitoring system called SNOTEL. What they've been finding, combined with SNOTEL and drought data, is concerning. I created the animation above to provide a visual sense of what's happening. The first frame shows the snow water equivalent in the mountains of the West at the end of January 2011, ...