NASA satellite imagery illustrates the dramatic reduction of snowpack in Utah between late February and late March. Illustration: Guardian Design/NASA Worldview
Recent snow surveys conducted across the American west indicate a troubling trend, as an exceptionally warm winter paired with unprecedented March temperatures has left snowpack levels at historically low points throughout the region.
Experts have cautioned that, despite a potential for more snowfall in the coming weeks, the extraordinary rate of melt-off experienced over the past month has placed critical basins in an uncharted situation heading into the dry season. They assert that any additional precipitation may come too late to make a meaningful difference.
“This year is on a whole other level,” remarked Dr. Russ Schumacher, a climatologist at Colorado State University, regarding the extreme heat that accelerated the melting of an already meager snowpack in March. “Observing this year fall significantly below all previous years for which we have data is deeply concerning.”
Snowpacks serve as vital reservoirs, functioning like a water savings account for the region. Measurements collected across the west during the week of April 1 are crucial in predicting the peak volume of water that could eventually flow into reservoirs, rivers, and streams, ultimately replenishing arid landscapes throughout the summer.
The issues affecting experts extend beyond the visible accumulation of snow at higher elevations; they are also concerned about the quantities of moisture still encapsulated within that snow. The concept of "snow water equivalent" (SWE)—which indicates the volume of water that can potentially melt and feed both natural and artificial water systems—is alarmingly low.
As of Monday, California's Sierra Nevada recorded a mere 4.9 inches of SWE, which is 18% of the historical average, according to the state's Department of Water Resources. In the Colorado River's headwaters, which supports over 40 million individuals, SWE was just over 4 inches, representing only 24% of average levels—this figure stands at less than half of what has been previously categorized as a record low.
Dr. Schumacher observed that while an approaching storm could temporarily slow the rate of melting, it would not suffice to restore the basins to a healthier state. SWE measurements recorded at the onset of April resembled those typically seen in May or June, indicating substantial melt-off that was already underway.
Data sourced from a division of the U.S. Department of Agriculture (USDA) reveals that states in the Southwest and Intermountain West are experiencing critically low levels. The Great Basin recorded only 16% of the average SWE this Monday, while the lower Colorado region marked 10%, and the Rio Grande was assessed at 8%.
“This year has the potential to be significantly worse than any previous years we have analogues for,” Dr. Schumacher warned.
Despite relatively normal precipitation rates across most of the western United States, each major river basin in the region had been contending with snow drought as March commenced. Approximately 91% of snow stations reported below-median snow water equivalent levels. Water managers and climate scientists had held hope for a March miracle; however, an extreme heatwave, unprecedented for the season, led to rapid snowmelt.
“March is typically a pivotal month for snowstorms,” Dr. Schumacher noted. “Instead of the expected snowfall, we experienced this extraordinary, off-the-charts warmth.”
In March alone, over 1,500 monthly high-temperature records were shattered. According to climate scientist Daniel Swain, the situation likely marks one of the most statistically aberrant heat events recorded in the American Southwest.
“Beyond the evident strangeness of it all,” Swain stated, “the most significant consequence of our record-breaking March heat will likely be the destruction of the snowpack for the water year 2025-26 across nearly all of the American West.”
Describing the impact of this heat wave as “nothing short of shocking,” Swain emphasized that California is currently tied for the worst mountain snowpack level recorded in history.
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