Historic flooding strikes Yellowstone National Park

Today’s Image of the Day from NASA Earth Observatory features a comparison of snowpack in Yellowstone National Park on June 16, 2021 and the same day in 2022. As America’s first national park is celebrating its 150th anniversary, it is also experiencing historic flooding that has not been seen in the region for a century. 

According to the National Weather Service, warm weather and heavy rainfall in Billings, Montana led to flooding rarely or never seen before across many area rivers and streams.

“In the second week of June 2022, an atmospheric river – a narrow band of tropical moisture – soaked the Pacific Northwest before dumping several inches of rain on northern Wyoming and southern Montana. The inundation coincided with a warm spell that exacerbated melting of the heavy snowpack,” reports NASA.

“On June 13, park officials closed Yellowstone – which spans 2.2 million acres (8,900 square kilometers) in northwest Wyoming, southwest Montana, and eastern Idaho – and announced the evacuation of more than 10,000 visitors due to safety concerns. Campsites were flooded, roads were washed out, and rocks tumbled onto roadways.”

Despite a slow start to the 2021–2022 water year, a cool, wet spring brought much-needed water to the region, which has been experiencing drought conditions. In April, higher than median precipitation in the Yellowstone basin helped build up the snowpack on the ground, which had increased to nearly the 30-year median by May. The Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Terra satellite captured these images 

The Billings National Weather Service explained that between June 10 and 13, the Absaroka and Beartooth ranges received between 0.8 and five inches of rain, which combined with two to nearly five inches of snowmelt. The collective water – equivalent to four to nine inches of rain – flowed over soil that was already soaked. 

“The runoff deluged the Yellowstone, Stillwater, and Clarks Fork rivers and their tributaries. At Corwin Springs, north of Gardiner, Montana, the Yellowstone River crested at 13.88 feet on June 13, 2022, breaking the previous record of 11.5 feet set on June 14, 1918,” reports NASA.

“A record river discharge of 51,400 cubic feet per second was also measured that day, breaking the previous record-high flow of 32,200 cubic feet per second in 1996, according to U.S. Geological Survey stream gauges.”

“North of the park, Gardiner and Cooke City were isolated by the rising floodwaters, which washed-out roads and bridges, swept away multiple houses, and flooded hundreds more. Rock Creek took out several bridges and flooded businesses in the historic downtown of Red Lodge, Montana. The flooding also caused power outages and compromised drinking water supplies in several towns.”

“The northern part of the park, where the river flows through steep canyons, suffered the most damage as the Yellowstone River cut a new course. The road between Gardiner and the park headquarters near Mammoth Hot Springs, a main supply route into the park, was washed out and it is expected to take months to repair.”

The north and northeast entrances to Yellowstone have basically vanished in the floodwaters, and are closed indefinitely.

Image Credit: NASA Earth Observatory

–—

By Chrissy Sexton, Earth.com Staff Writer