New 'snow eater' heat waves melt Western snowpack faster and earlier
Researchers have coined the term “snow eaters” for spring heat spells that keep temperatures above freezing all day, dramatically speeding snowmelt across the Western United States.
Climate scientists, including Matthew LaPlante of Utah State University, have identified a distinct class of spring heat events called “snow eaters.” Published in Science Advances, the research finds these episodes occur when temperatures remain above freezing around the clock for three to five days, causing snow to melt at roughly twice the normal speed. Since the 1850s, the region impacted in the Western United States has expanded by an average of about 40,000 square miles per century, and the first snow-eater of the season now arrives about one month earlier per century.
The rapid melt poses flood hazards, reduces water stored for summer use, and fuels more severe wildfires, according to experts such as Noah Molotch and Ben Hatchett. Solar radiation, a major driver of melt, interacts with these warm spells to create a feedback that further accelerates snow loss. Although the study focused on the West, similar patterns likely exist elsewhere, prompting calls for improved forecasting to aid water managers and outdoor safety.
Why it matters
Earlier, faster snowmelt threatens water supplies, flood control and wildfire risk for millions in the West.
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