Colorado’s snowpack tells the story of water in the West

A student measuring snow near the Niwot SNOTEL site.

A student looking at snowflakes under a magnifying glass.

Closeup of a snowflake measuring tool.

At 9,500 feet on an early spring day, Jennifer Kay would usually expect to find thick snow blanketing the CU Boulder’s Mountain Research Station, an alpine monitoring and research site 25 miles west of Boulder. 

But this March, as Kay stepped out of her car, she found bare ground. 

Kay, professor in the Department of Atmospheric and Oceanic Sciences and a fellow at the Cooperative Institute for Research in Environmental Sciences (CIRES), was leading a field trip of nine students to a SNOTEL, or snowpack telemetry, station at Niwot Ridge. The station, sitting at 9,940 feet above sea level, is one of over 900 snow monitoring stations located across the West. 

These stations autonomously measure and weigh the amount of snow that has fallen. Since the establishment of the SNOTEL network starting in the 1960s, scientists have rarely seen numbers as bleak as this year’s. Over the past winter, the Niwot SNOTEL site received only about a quarter of its normal snowfall. 

Record-low snowpack 

Across the American West, an unusually warm and dry season has left snowpack at historic lows. In Colorado, peak snowpack was just 40% of normal this spring, and a record-breaking March heatwave triggered snowmelt more than a month early, during what is typically the region’s snowiest time of year. 

These unusual conditions are upending a system that more than 80 million people depend on for water and raising concerns about worsening drought, extreme heat and elevated wildfire risk. 

Stalled jet stream 

Snowpack acts like a frozen water tower, storing water in the winter and then releasing it into rivers and reservoirs in early summer. 

Snowmelt is particularly important to the American West because it serves as the primary water source for many states, including Colorado. Niwot Ridge is part of a watershed that provides about 40% of the water for the City of Boulder. 

The snow drought that heavily affected almost all western states this winter is linked to the interplay between the atmosphere and the ocean, said Andrew Winters, assistant professor in the Department of Atmospheric and Oceanic Sciences. 

“This snow pattern is really outside of the realm of what we’ve seen for at least 40 years,” he said. 

Based on data from the U.S. Department of Agriculture, the 2026 snow year was the lowest on record across the Upper Colorado River Basin, a watershed spanning four states in the Southwest. 

“The year 2002 marked the beginning of a ‘mega-drought’ in the Colorado River Basin,” said Keith Musselman, assistant professor in the Department of Geography and a fellow at the Institute of Arctic and Alpine Research (INSTAAR). The drought significantly reduced the amount of water stored in reservoirs, including Lake Mead and Lake Powell, and caused record-breaking wildfires. This year’s snowpack, he said, is even lower. 

Snow hopes ahead 

Scientists are uncertain where the jet stream will track next winter. Winters said the Pacific Ocean is expected to shift into El Niño conditions, which typically push the jet stream farther south and could bring more snow to parts of the West, including Colorado. 

“Historic years like this one are challenging for water and fire, and make us all appreciate the importance of snow for the West,” Kay said. “Understanding the odds of having another winter with atmospheric patterns like 2026 is definitely an active and important area of research.”