It's been an abnormally warm winter, and snowpack is below average across most of the Upper Colorado River Basin. Basin-wide, snow-water equivalent, or the amount of water stored in snowpack, is about 75% of median for this time of year.
In the northern parts of the Upper Colorado River Basin, snow-water equivalent is near or above average. The Upper Green River Basin in Wyoming, for instance, is at 137% of usual snowpack for this time of year. But along the river's main stem in Colorado and Utah, and further south, that number is much lower. The Gunnison River Basin is at 63% of the median snow-water equivalent for this time of year, the Colorado River headwaters are at 58%, and the San Miguel, Dolores, Animas, and San Juan river basins are at 56%.
A big reason for the lack of meaningful snowpack is warm temperatures. Across the basin, temperatures were 5-10 degrees above average in November, and 9-12 degrees above average in December.
Seth Arens, a research scientist with the Western Water Assessment, said right now, most SNOTEL monitoring sites, which track snowpack and snow-water equivalent, should have accumulated between 25% and one-third of their total accumulation for the water year.
"There's a lot of snow accumulation season left, that we could start to catch up towards average snowpack," he said. "That said, the weather patterns we've been seeing so far this year have been pretty persistent and kind of anomalous."
Forecasters are predicting an inefficient runoff, meaning that not all of the water stored in snow will make it into rivers this spring. The Colorado Basin River Forecast Center is currently predicting 57% percent runoff for this spring. Arens said that's likely due to a lack of snow at lower elevations.
"There's a lot of areas in those lower elevations that do contribute to runoff," Arens said. "And a lot of those areas where there would be additional snow water coming in during runoff season—they're not snow-covered this year."
Arens said that due to climate change, the region will probably see more winters like this one in the future, but he wouldn't call it "the new normal."
"We're going to keep going through these cycles of having warm winters and cold winters, but that average is going to get higher and higher," he said. "So that means on these extremes: our extremely warm winters are going to be warmer and warmer, and the extremely cold winters aren't going to be as cold."
Low snowpack this winter could also have dire consequences for the entire Colorado River Basin. The seven states that use the river are in the midst of years-long negotiations over how to allocate diminishing water, and have until February 14, 2026, to submit a plan to the federal government.
Arens thinks that by the end of Water Year 2025-26, water levels in Lake Powell, one of the river's largest reservoirs, will hit record lows. The current lowest recorded water elevation was about 30 feet above minimum power pool, or the amount of water needed to generate hydroelectricity at Glen Canyon Dam.
"I think it's pretty likely at this point that we'll get lower than that," Arens said. "The question is (whether) we'll get all the way down to that elevation where they have to turn off power generation."
Copyright 2025 Rocky Mountain Community Radio. This story was shared via Rocky Mountain Community Radio, a network of public media stations in Colorado, Wyoming, Utah, and New Mexico, including KSJD.
