A warm winter and above-average spring temperatures to come are crushing forecasters’ hopes for more snow in the Rocky Mountains in a season that could rival 2002, a disastrous year that plunged the Colorado River Basin into the 21st century megadrought.
As of March 1, Lake Powell was only expected to receive 36 percent of normal inflows, which could make for the fifth lowest runoff season on record. That’s a troubling sign for the Colorado River Basin as tensions flare between state officials who have failed to deliver an agreement for how to share a shrinking river over the next 20 years.
“The best we can hope for is to get from historically low to just bad,” said Russ Schumacher, Colorado’s state climatologist and a professor at Colorado State University. “That’s the best we can hope for at this point.”
Southern Nevada depends on Lake Mead for about 90 percent of its water supply, and levels upstream at Lake Powell directly connect to how much water can be released. Current federal projections show Lake Powell falling below the level at which Glen Canyon Dam can generate power, though it’s likely the Bureau of Reclamation will move water in from an upstream reservoir to avoid that scenario.
In the headwaters of the Colorado River, snowpack is the lowest it’s been on record at 65 percent of average, with measurements going back to 1986. Nearly every portion of the seven Colorado River states is forecast to have a 90 to 100 percent chance of above-normal temperatures, according to the National Oceanic and Atmospheric Administration.
“It’s going to be way warmer than average for several days, with lots of records broken, most likely,” Schumacher said. “That’s not a formula for building up snowpack. That’s a formula for making it go away early.”
Warming trends a sign of the times
While forecasts are never an exact science, Schumacher said it’s likely that the early seasonal heat is coming to the West.
“It’s not too common for all the models to agree that there’s going to be a big high pressure and then for it not to come through,” he said. “It’s more a question of the magnitude and exactly how long it sticks around.”
In many places, snow is already melting at low elevations. Normally, March and April present water managers with another chance for snowpack to bounce back.
Dan McEvoy, a climatologist at the Desert Research Institute and Western Regional Climate Center, said the only sections of the American West that he expects to get any significant snow in the next week are the Pacific Northwest and parts of Montana.
The snow deficits were so large in the Colorado River Basin already that McEvoy said regular temperatures probably wouldn’t have moved the needle very much, anyway. But the temperatures to come are concerning, and secure this season’s fate as “bottom of the barrel” in terms of snowpack.
“This is kind of the worst-case scenario when you’re already in really low snowpack conditions,” McEvoy said. “We have had years in the past where March and into April has brought a lot of snowfall to the mountains and colder temperatures. It can still feel like winter in the mountains. But it doesn’t seem like that’s going to happen this year.”
Both Schumacher and McEvoy said the public should keep an eye on wildfire forecasts, as worse snow seasons often give way to drier conditions and more fire weather.
Schumacher said snowpack melting earlier can have wide-reaching implications for water users, particularly the agriculture and recreation sectors that depend on water flows into the late summer.
Warmer air means more evaporative losses and less time for snowpack to accumulate over a full season, he said.
“We’re still going to have big swings from year to year, where there’s going to be years with lots of snow in the mountains and years with very little like we have this year,” Schumacher said. “Warming has tilted things towards the worst outcomes when it comes to water.”
Contact Alan Halaly at ahalaly@reviewjournal.com. Follow @AlanHalaly on X.
