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Forecasters say coming winter storms won’t be enough to prevent drought when runoff season starts

Snow along the banks of the Colorado River in Glenwood Springs in January 2024.
Caroline Llanes
/
Rocky Mountain Community Radio
Snow along the banks of the Colorado River in Glenwood Springs in January 2024.

A dry autumn, followed by a dry start to the year has water researchers worried about drought conditions this coming spring and summer.

Southern Colorado, Utah, and the Four Corners region are experiencing much lower than average levels of snowpack for this time of year, according to the National Integrated Drought Information System (NIDIS). Snow telemetry (SNOTEL) monitoring sites are showing as low as 47% percent of normal in places like Mancos, Colorado, and 42% in the Upper San Juan. Monitoring sites near Grand Junction and Paonia are doing a little better, but still low, measuring between 60% and 87% of normal for this time of year.

The snow water equivalent (SWE), or how much water is stored in snowpack, is at a record low in some places in southern Utah. The Lower Colorado-Lake Mead basin is at 29% of normal SWE, the Escalante Desert-Sevier Lake basin is at 51% of normal SWE, and the Upper Colorado-Dirty Devil Basins has 56% of normal SWE.

In addition, NIDIS says February temperatures were 4 to 6 degrees above normal in much of southern Utah and western Colorado, which helped to drive a lot of the snow drought conditions. The National Weather Service reported six new days of record highs in Grand Junction.

Further to the north, however, the Upper Colorado River Basin isn’t experiencing nearly as much snow drought. That includes Wyoming and northern Colorado and Utah, as well as the high country in the central mountains. For example, SNOTEL monitoring stations near Aspen and Jackson are reporting snowpack between 90% and 115% of normal for this time of year.

What does that mean for spring runoff? 

Forecasters are predicting an “inefficient runoff” for much of the Upper Basin, which means a good portion of snowpack will not actually make it into rivers and streams this summer.

Seth Arens, a research scientist with the Western Water Assessment, says a likely reason for that is a lack of soil moisture.

“A setup that often is really good for runoff, is if we have a wet fall leading up to when the snow starts falling,” he said. “So if those soils are really wet, then you get the snow on that. And those soils stay wet because once the snow is on the soil, you're not going to get any evaporation from the soils.”

Arens said that wasn’t the case this fall.

“Preceding when snow started to fall, we had hot weather, dry conditions, any soil, any water that was in the soil was getting evaporated out of the soil, so the soils were drying out in October,” he said.

October brought record-breaking temperatures to much of Colorado and eastern Utah, as well as Wyoming. Dry conditions also persisted throughout the region.

Arens said inefficient runoff would likely be a problem for most of the Upper Colorado River Basin this spring, but some watersheds may stay closer to normal, based on forecasts. That includes the headwaters of the Colorado River, the Yampa River, and the Gunnison River. Watersheds that are predicted to experience that inefficient runoff include the Green River upstream of Flaming Gorge Reservoir, and the Dolores and San Juan rivers.

A winter storm is predicted to bring snow to much of the Rocky Mountains later this week, with snow predicted to start on Wednesday in Utah and Wyoming, and on Thursday in Colorado. Arens said while it may bring some relief, it likely won’t be enough to bring runoff back up to average.

“Our seasonal forecasts are pointing to a drier and warmer than average spring,” he said. “In recent history, we've seen warm, dry springs that then have this negative impact on the amount of runoff that's being generated from the snowpack.”

Climate change and drought forecasting

Arens said human-caused climate change is having a big impact on how researchers and forecasters look at big systems like the Colorado River as a whole.

“Without even thinking about changes in precipitation, just the impact of increases in temperature will, in general, push our river systems to (be) drier and overall having less water in the system,” he said.

A big part of that is that weather models that forecasters use are based on historical climate data, and oftentimes, data points like “average snowpack for this time of year” are taken using 30 years’ worth of data. But as conditions change, that gets more difficult.

“In wonky meteorology speak, we're moving from a stationary climate to a non-stationary climate,” he said. “Meaning that we're changing from a climate that has been relatively stable in these climate patterns, to a climate that is much more erratic. There's going to be more extremes. There's going to be some weather patterns, maybe, that are kind of outside of what we've been predicting.”

Arens said it’s changing the way that scientists and forecasters are thinking about their models and data.

“Some of those models might start to be not the best tools anymore, just because the physical conditions are changing and there's not necessarily good predictive tools to do that differently yet,” he said, adding that researchers don’t yet have enough information, in a lot of cases, to craft new models that describe the new patterns weather we’re seeing.

“We just know that (patterns) are changing, and they're changing in unpredictable ways, and they're changing in ways that we're seeing more extreme weather in both directions: extreme wet, extreme dry.”

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 Aspen Public Radio.

Caroline Llanes is the rural climate reporter for Rocky Mountain Community Radio. She was previously a general assignment reporter at Aspen Public Radio, covering everything from local governments to public lands.