A new category of heat waves is melting western US snowpack faster

Researchers have identified and named a new category of heat wave, called a snow eater, that rapidly melts mountain snowpack in the Western United States. A study published in the journal Science Advances found these events occur when temperatures stay above freezing both day and night for multiple days, typically three to five, roughly doubling normal snowmelt rates. The study found that since the 1850s, the area affected by these heat waves has expanded by about 40,000 square miles per century, and the first snow eater of the season now arrives about one month earlier per century. Researchers say the phenomenon has contributed to record low snowpack across the West this spring and may be linked to increased flooding, water management challenges, and wildfire risk.