Worst snow drought in decades grips much of Western U.S.

A record snow drought and unprecedented warmth are undercutting mountain snowpacks across much of the American West, with officials and scientists warning that the impacts could carry into spring and summer. The Associated Press reported that scientists are seeing snow cover and snow depth at the lowest levels in decades, and that the pattern is developing as many Western states brace for less runoff later in the year.

The National Snow and Ice Data Center director Mark Serreze said he has not seen a winter like this before. He described the underlying weather pattern as “so darned persistent,” as he spoke after decades in Colorado observing seasonal cycles.

Scientists said the magnitude of the shortfall is visible in broad measurements of snow extent. In normal conditions for this time of year, scientists said snow cover should be about 460,000 square miles—roughly the size of California, Utah, Idaho and Montana. This year, they said, snow cover was only about 155,000 square miles, California-sized, according to the National Snow and Ice Data Center.

NOAA-linked monitoring points to unusually deep deficits in the snowpack that stores water for later release. Jason Gerlich, the regional drought early warning system coordinator for the National Oceanic and Atmospheric Administration, said Oregon’s snowpack is both record low and about 30% lower than the previous record. Gerlich said the Upper Colorado River Basin is at the center of the snow drought because the basin depends on mountain snow that gradually melts as winter warms into spring.

Water managers and researchers said the issue is not only how little snow is present now, but the timing of how water reaches rivers. Experts said a robust snowpack helps supply a steady flow of water into creeks and rivers that supports agriculture, cities and hydropower. They warned that a lack of snow—or snow that melts too fast—could leave less water available later in the season, and Daniel Swain of the University of California’s Water Resources Institute called it “a pretty big problem for the Colorado basin.”

The AP reporting also connected the snow drought to wildfire risk, citing research on how earlier snow loss can change ground conditions. Daniel McEvoy of the Western Regional Climate Center said snow disappearing earlier than average leaves the ground exposed to warmer weather in the spring and summer, which dries soils and vegetation sooner—conditions that can help kick-start an early wildfire season.

The warming is also showing up in temperature records across the West, not only in snow measurements. Since Dec. 1, NOAA data cited by the AP showed more than 8,500 daily high-temperature records have been broken or tied in the region. Scientists told the AP that much of the precipitation that would normally fall as snow and stay in the mountains is arriving as rain instead, which runs off faster and reduces the amount stored for later.

While the AP noted that going snowless can happen at times, scientists emphasized that the warmth driving this winter’s pattern is unusually extreme and easier to link to climate change from the burning of coal, oil and natural gas. Russ Schumacher, a professor of atmospheric science at Colorado State University and Colorado State Climatologist, said the warmth was so extreme—especially in December—that snow was falling only at the highest mountain elevations, and that the following weeks turned dry almost everywhere while staying warm. McEvoy said, “It was so warm, especially in December, that the snow was only falling at the highest parts of the mountains,” adding that the pattern shifted as the period moved into January.

In Utah, the snow drought has also been visible in day-to-day winter conditions. Trevor Stephens, a West Jordan, Utah resident, described going to a store in gym shorts and a T-shirt and said there was “no snow on the ground,” lamenting a lack of snowboarding opportunities.

Looking ahead, meteorologists expect wetter and cooler weather this week, with some snow possible, and the AP reported this could be near the peak of the snow drought. However, Schumacher said he does not think there is “any way we’re going to go back up to, you know, average or anywhere close to that,” though he said conditions may still allow deficits to be chipped away if the weather pattern becomes more active.