Scientists define a new category of heat wave: ‘Snow eaters’
Unseasonably warm weather that rapidly melts snowpack is becoming more widespread in the U.S. West and happening earlier in the year.
Matthew LaPlante, a climate scientist at Utah State University, observes the effects of his research on a daily basis from his home high above Salt Lake City. Warm nights above freezing cause the snow level to lower, revealing more of the aspens he taps for syrup. This experience inspired scientists to coin the term "snow eater" to describe a new type of heat wave that occurs in the spring and early summer.
A study in Science Advances, led by LaPlante, identified the specific conditions that create these snow eater events. These events require temperatures to stay above freezing both day and night for at least three to five days in a row, causing snow to melt at a significantly faster rate than usual. This can lead to flooding and make water resource management more challenging.
The study found that snow eaters have been happening more frequently and earlier in the season in the Western United States due to climate change. Since the 1850s, the area affected by snow eaters has expanded by an average of about 40,000 square miles per century, with the first snow eater of the year arriving about one month earlier per century.
The term "snow eater" has a complicated history, with references dating back to the 1880s and more recent headlines in March when an early heat wave wiped away snowpack in the Colorado Rockies and California's Sierra Nevada. Scientists hope the catchy term will draw more attention to this phenomenon, as there is still much to learn.
While the study focused on the Western U.S., snow eater heat waves likely occur elsewhere. Solar radiation is a major driver of snowmelt and can be amplified when combined with heat waves. This creates a "snowball effect," where warming snow crystals lose their reflective properties, causing them to absorb more sunlight and melt faster.
The West saw record-low snowpack this spring, with Colorado receiving less precipitation than normal while California got rain instead of snow. However, across the region, above-average temperatures have been a common factor. These conditions have likely contributed to severe wildfires in the region. Mountain forests in the Western U.S. rely heavily on snow accumulation for water availability during the summer, making drought stress a critical factor for wildfire intensity and frequency.
Better prediction of snowpack behavior could help water managers plan for the future. Early or rapid snowmelt poses challenges for water resource management, as melted snow becomes a hazard instead of a resource for reservoirs and rivers. Snow eater heat waves may also pose risks to outdoor enthusiasts, such as skiers and hikers, and could be linked to hazards like avalanches and permafrost melt, though those connections are still being investigated.
Written by urgent.news from Grist's reporting — not their text. Machine-written — it may contain errors, so check the original before relying on it.
