Rapid snowmelt threatens US West water supply outlook

Rapid melts across the U.S. West have caused snowpack to disappear up to four weeks early in some areas — wreaking potential havoc on the region's water supply, federal meteorologists warned Thursday.

These conditions have particularly affected parts of Utah, Colorado and New Mexico, causing some basins to shift from above-average snowpack to "snow drought," according to an update from the National Integrated Drought Information System (NIDIS).

That transition occurred in under a month, with snow disappearing one to four weeks earlier than usual, the NIDIS updated stated.

Tracking snow drought — a period characterized by abnormally little snow for a given time of year — is critical to assessing potential impacts to water supply, soil moisture and wildfire potential, the meteorologists noted.

Washington state and Utah have already declared drought emergencies due to low snowpack, as well as below-average streamflow forecasts and long-term impacts of dryness, according to the NIDIS.

The Washington State Department of Ecology recently declared an emergency in the Yakima Basin, while issuing advisories for several watersheds in the central and northern Cascades.

Meanwhile, Utah Gov. Spencer Cox (R) last week published a drought executive order that announced a state of emergency in 17 counties.

“I urge all Utahns to be extremely mindful of their water use and find every possible way to conserve," Cox stated at the time. "Water conservation is critical for Utah’s future.”

As for the Colorado River Basin, the NIDIS update said that supply forecasts for this region declined in comparison to April 1 projections, presumably due to dry conditions and early, rapid snowmelt.

Peak snow-water equivalent — the amount of water contained in snow — in the Southwest was also much below the median, according to the report.