Much of the Western United States has experienced one of its warmest winters on record, leaving snowpack at historic lows and prompting warnings of drought and wildfires this summer. An early March heat wave pushed temperatures into triple digits across multiple states. Experts describe the conditions as unprecedented, with no historical parallels.
In Park City, Utah, skiers encountered patches of grass on slopes throughout much of the winter, signaling a season that largely failed to materialize. Snowpack, which provides 60 to 70 percent of the Northwest's water supply and is vital for the Colorado River Basin serving seven states, now stands at record lows, according to the federal Colorado River Basin Forecasting Center. Hydrologist Cody Moser reported that the upper Colorado River basin's snow cover fell from 40 percent of normal in early March to 25 to 30 percent recently, based on the Snow Telemetry network's half-century of data. Marianne Cowherd, a climate scientist at Montana State University, noted, “There is no analog... This limits our ability to look to the past for insight.” She added that precipitation arriving as rain rather than snow leads to evaporation or runoff to the ocean, bypassing storage in rivers and reservoirs. “Even when we’re getting precipitation, we’re not storing it,” Cowherd said. We lack reservoir capacity to hold needed water volumes, she warned, as warmer temperatures accelerate melt while lower spring solar angles may slow it. A mid-March heat dome brought temperatures up to 35 degrees Fahrenheit above normal, shattering over 1,500 daily records in 11 states and setting a national March high of 112 degrees Fahrenheit in four cities, per Climate Central. The World Weather Attribution Initiative deemed the event “virtually impossible” without climate change. Clair Barnes of Imperial College London’s Centre for Environmental Policy stated, “The role of climate change is clear,” highlighting risks from early-season extremes before bodies acclimatize. These conditions threaten Lake Powell's power generation levels as early as August, according to the U.S. Bureau of Reclamation. Denver Water declared a Stage 1 emergency, mandating 20 percent usage cuts and outdoor watering bans. CEO Alan Salazar said, “This winter was unusually warm and did not deliver the snow we need... a reminder of the impacts of climate change on our water supply.” Early vegetation growth amid heat raises wildfire dangers, warned August Isernhagen of the Truckee Meadows Fire Protection District, citing potential for unprecedented fire season conditions. While an El Niño pattern or late snow could mitigate risks, Cowherd said such outcomes appear unlikely based on forecasts.