Winter Snowmelt Increasing, Raising Western Snowpack Concerns
New research published in the journal Nature Climate Change finds that snow is melting earlier – often in the winter. That’s a bad sign for the Mountain West.
Researchers took an unprecedented look at more than 1,000 snow measurement stations from New Mexico up through Canada and Alaska. They found that over the last 40 years, about a third of those stations recorded increasing winter melt.
Study lead Keith Musselman is a researcher at University of Colorado Boulder's Institute of Arctic and Alpine Research. He says the study suggests that snowpacks are being affected by climate change, even if snowpack averages have been relatively stable over the last few decades.
“In some cases it’s validation of our future projections that snow quality (and) snow quantity will be expected to continue to decline,” Musselman said.
Mountain snowpacks feed rivers and streams and fend off summer drought in the West. If warming increases, and they shrink or melt earlier, that can mean more wildfires and challenges for farmers later in the season.
But winter snowmelt is bad for other reasons, too. It means crustier snow for skiers and snowboarders, and more saturated ground during the winter. That can keep the ground warmer, which means microbes can stay awake longer and continue exhaling carbon emissions. Beyond that, wet ground increases the risk of flash floods.
“More frequent winter melt really fills up that reservoir – that soil reservoir – and reduces that buffer that can protect us against floods,” Musselman said.
Study authors also suggest that winter snowmelt may be a good way to measure changes to snowpack going forward because it depends more on temperature than precipitation. The study found increased winter runoff in three times as many locations than they saw decreased snowpack.
This story was produced by the Mountain West News Bureau, a collaboration between Wyoming Public Media, Boise State Public Radio in Idaho, KUNR in Nevada, the O'Connor Center for the Rocky Mountain West in Montana, KUNC in Colorado, KUNM in New Mexico, with support from affiliate stations across the region. Funding for the Mountain West News Bureau is provided in part by the Corporation for Public Broadcasting.