The intensity and frequency of extreme weather events are generally rising due to climate change, but the enormous snow dumps that periodically wreak havoc on the U.S. West may not be affected in the same way.
According to a recent study that was published on Monday in the Proceedings for the National Academy of Sciences, the amount of snow that falls during so-called “snow deluge” years—like the significant snow season in California in 2023—is declining.
Adrienne Marshall, lead author and assistant professor of geology and geological engineering at Colorado School of Mines, stated in a statement that “there’s a common narrative with climate change that extreme weather events are getting more extreme.”‘
“But with snow deluge, we’re not seeing that’s the case,” Marshall further added. “Instead, what we’re seeing across the western U.S. is that snow deluges decline, too.”
The scientists used automated snow telemetry observations—unattended, automated snow measurement sites that send data to a central database—as well as snow survey results and data from California’s Sierra Nevada to reach their conclusions.
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According to the researchers, a moderate warming scenario by the end of the century would result in a 58 percent decrease in the amount of snowfall during deluge years.
According to the study, they found that the amount of snowfall in a typical year will decrease much more during the same time, by almost 73 percent.
“Should we expect our big snow years to stop happening? The answer we get here is, ‘Kind of,'” Marshall stated.
The study found that the snow-water-equivalent, or the volume of water in the snowpack, at its peak on April 1, 2023, indicated that the California flood was roughly a once in 54-year occurrence.
On the other hand, snow droughts are becoming more frequently. The scientists pointed out that although deluges require both cool and wet conditions, these snow-free intervals can occur due to warmth or dryness alone.
Although warmer doesn’t always translate into less precipitation, it does raise the likelihood that it will come in the form of rain, which doesn’t build up on mountains and melt in the spring like snowpack does.
The authors’ conclusion was that their findings applied not only to California but to regions throughout the American West, and they might have a significant influence on both people and wildlife.
Snow deluges can either prolong the winter ski season or reduce activity because of infrastructural damage, according to recent experiences, the researchers said. The amount, timing, and melting of snow have an impact on summertime recreation and hydropower operations.
Even though snow deluges might increase a region’s water supply, the authors caution that they can also “breed complacency” because they can produce surprisingly significant runoff in a given year. Managers may feel less pressure to create adaption plans with such unexpectedly abundant supply, the researchers continued
“Snowpack acts as a massive reservoir that stores water for the summer when we need it most,” Marshall stated. “When we lose that, we get runoff at a time of year when we don’t need it as much.”
