Roundup: Rapid snowpack melt in Rocky Mountains foils drought relief hopes in U.S. West-Xinhua

Roundup: Rapid snowpack melt in Rocky Mountains foils drought relief hopes in U.S. West

Source: Xinhua| 2022-05-13 04:47:45|Editor:

by Peter Mertz

DENVER, the United States, May 12 (Xinhua) -- A warm, windy weather front from U.S. arid southwest brought words of dismay from climate scientists and havoc to residents of the High Rockies, where "Colorado's snowpack is melting at a 'ridiculous' rate," a headline of The Denver Post said this week.

"Last night our roof blew off and damaged both our cars," Lari Goode wrote on Facebook on Monday. Other residents of Carbondale, 6,181 feet (1883.9 meters) in elevation, posted pictures of toppled trees and Jae Gregory "clocked a (wind) gust of 72 miles an hour."

Red Flag Warnings with "high fire danger" continued Thursday for most of Colorado, also nicknamed the Centennial State, and throughout neighboring states of New Mexico and Arizona, CBS4 Denver reported. Much of the region braced for possible wildfires triggered by hot weather, humidity under 15 percent, and continuing winds of between 45 and 60 miles per hour, local meteorologists reported.

Colorado's aberrant weather produced record low temperatures in the past winter and delivered an above-than-normal snowpack. However, there was a record high of 89 degrees Fahrenheit (31.6 degree centigrade) last Saturday and it is expected to break more high temperature records this week, according to the Colorado Public Radio (CPR).

"Colorado didn't see enough snow this winter to fully recover from the ongoing megadrought and now what snow the state did see is melting too quickly," weather experts told The Denver Post.

Predicting a "complete melt out by the end of May or beginning of June," an official with the Colorado Climate Center (CCC) told the newspaper, "that's too soon, by several weeks," worsening drought conditions "and exacerbating what officials are anticipating could be the worst wildfire year in Colorado's history," according to the report on Tuesday.

Rivers were surging and waterfalls gushing outside of the town of Marble in Colorado, and local residents are recovering from the high wind blasts and dust that hit the region Sunday night, which toppled trees, tore roofs from homes, and caused a power outage lasting 12 hours on Monday.

The heavy winds scattered a layer of brown dust throughout the High Rockies that "came from the dry landscape of the southwestern United States," CBS4 News reported Tuesday, adding that "a substance with a darker color to the top of snow isn't good when it comes to the spring melt."

The widespread dust blanket "means that the snowpack is retaining more of the incoming solar energy, which is helping to speed up the melt," CBS4 added, but it "isn't the only factor working to accelerate the spring melt in Colorado, with both the lack of snowstorms and above normal temperatures also playing a big role."

DOWNSTREAM

With the U.S. West "still in the grip of the worst megadrought in 1,200 years," the sudden meltdown has dismayed climate change scientists who call "the mountain snowpack a natural reservoir" that "provides a steady supply of water for millions of people who rely upon it for agriculture, industry, and municipal and residential use," NASA's Earth Observatory reported last month.

"The Colorado River needs a big moisture boost," CPR said Tuesday, adding that "runoff forecasts suggest it won't come from spring snowmelt."

An April 18 report by the Colorado Basin River Forecast Center anticipated a "near-average to much-below average water supply volume for April to July 2022 across the Upper Colorado River Basin and Great Basin," a prediction that has melted away in just the past week.

"Water managers really like to see how much snow there is and what the percentage average is at different elevation bands," said Noah Molotch, a researcher at the Institute of Arctic and Alpine Research (INSTARR) in Boulder, Colorado.

"Water managers know that snow from low elevations will run off earlier and increase stream flow early in the season, whereas higher elevations run off later and will be the primary source of streamflow later," he added.

The amount of water forecasted to flow into Lake Powell is a good marker for the overall health of the upper half of the Colorado River system, the CPR said, noting that "the reservoir on the Utah-Arizona border, the nation's second-largest, supplies water and electricity to millions of people in the West."

With Powell's water level dropping to its lowest level since 1963 when it was filled by the Glen Canyon Dam, the U.S. Bureau of Reclamation recently announced emergency plans to protect the reservoir by holding back water releases to downstream states, the first time the agency has moved to delay a release of water from Lake Powell that normally goes to Arizona, California and Nevada.

According to NASA, the runoff forecast is worse in the south, where hydrologist Cody Moser said warmer-than-average temperatures have caused the snowpack to melt sooner and quicker.

Moser said parts of the upper Colorado River basin have got near-normal amounts of precipitation since fall of 2021, but "because the soil is drier with warmer temperatures, it soaks up a lot of the snowmelt before it reaches rivers and reservoirs."

"As snow melts, some of the state's waterways - like the Colorado, Gunnison, Rio Grande and San Juan rivers - might see a short-lived uptick but ultimately below-average flows in water," the CCC said.

The melt out also comes on the heels of an extremely dry April, which set records along much of Colorado's Eastern Plains, the Colorado Agricultural Meteorological Network said in a group climatologist discussion Tuesday morning.

The lack of moisture and early melt out increase the risk for wildfires across the state, and threatens Colorado's agricultural industry worth 47 billion U.S. dollars, CCC noted, and with "current trends, the state's drought conditions will only worsen heading into the summer."

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