After a very wet winter with plenty of other wild weather, regions across the United States are bracing for the risk of flooding as record-breaking snow begins to melt, putting millions of people at risk.
Here’s what you need to know about the riskiest places.
Flood risk closes Yosemite National Park
Most of the valley in the heart of California’s Yosemite National Park will close to visitors beginning at 10 p.m. on Friday, April 28, and will last until at least May 3. Valley.
[Related: There are rivers in the sky—and one is causing raging rain over California.]
Home to towering granite formations like El Capitan and Half Dome, as well as numerous waterfalls, the wildly popular park welcomed 3.6 million tourists in 2022.
Central California is bracing for the hottest temperatures of the year, as well as a looming heat wave with highs in the 90s Fahrenheit and overnight lows above freezing. According to the National Weather Servicetemperatures will be five to 15 degrees above average, and the heat is expected to hasten spring thaw after record winter snowfall in the Sierra Nevada mountain range.
A series of atmospheric rivers brought numerous snowstorms to the region this winter, with some parts of Yosemite seeing up to 15 feet of snow. The park was closed for about three weeks in February due to snowfall, which was one of Yosemite’s longest and most extensive weather-related closures.
California State Climatologist Michael Anderson noted that significant flooding was more likely later in May, not late April. Reservoir operators in the region are releasing water now to make room for more water as the spring thaw continues.
A large basin in the northern San Joaquin Valley along the Tulare River is a significant area of concern for flooding. A long-dry lake bed filled in with water from storm runoff and submerged large swaths of farmland and ranches.
Mississippi River cities brace for flooding
More than 1.4 million people were under flood warnings Tuesday, April 25, with warnings stretching along the Mississippi River from North Dakota to parts of Missouri.
Twenty river meters along the Mississippi River are in major flood stage, partly as snow begins to melt. Multiple cities in the Upper Midwest saw record snowfall this season, which could lead to some of the worst flooding in two decades.
[Related: Last year’s historic floods ruined 20 million acres of farmland.]
The Mississippi River at La Crosse, Wisconsin is forecast to crest near 16.1 feet Wednesday, April 26, through Thursday, April 27. This would be the third highest ridge in the area, measuring near the record of 17.89 feet set in April 1965. According to the NWS, “the water is within a foot of Rose Street near Interstate 90, and the exit of I-90 eastbound may be closed” if it reaches 16 feet.
Davenport, Iowa, has begun installing barriers to keep out floodwaters as the city of about 100,000 people braces for warm weather and snowmelt. The city is no stranger to these spring floods, but it is preparing for the worst. In 2019, Davenport and other parts of the Midwest saw record flooding, when gauges saw a crest flood of 22.7 feet.
Snow will continue to melt across the US as spring temperatures increase. To stay safe in floods, it’s critical to understand flood hazards and flood zones, and to always have an evacuation plan in case forecasts and water levels change. The Federal Emergency Management Agency (FEMA) has multiple flood maps that can help you assess your flood risk and plan accordingly.