Pederson says he's confident his tree-ring results are accurate in part because during a brief period of overlap during the 20th century, the snowpack depth derived from the tree rings and modern observations look like "photocopies" of one another.
Although the new study describes ongoing decline in snowpack throughout the Rockies, this year has bucked that long-term trend. Record snowpacks have been recorded in the northern West, according to the Agriculture Department's Natural Resources Conservation Service, which monitors snowpack.
Experts characterized it as a brief blip in a longer-term trend of decline. They attributed last year's unusually wet winter to the La Niña weather pattern that was in place from August to May.
"We're seeing 200 to 400 percent of normal for this time of year," said Michael Strobel, director of the service's National Water and Climate Center.
Reprinted from Climatewire with permission from Environment & Energy Publishing, LLC. www.eenews.net, 202-628-6500