The federal government's spring weather outlook issued Thursday shows flooding risk will remain high through May for 25 states, as Midwestern states are still coping with the disastrous effects of last week's "bomb cyclone" storm.
"Nearly two-thirds of the Lower 48 states face an elevated risk for flooding through May, with the potential for major or moderate flooding in 25 states," the National Oceanic and Atmospheric Administration said in its spring outlook report issued Thursday. "The majority of the country is favored to experience above-average precipitation this spring, increasing the flood risk."
The forecast comes as communities in the Midwest cope with historic flooding caused by rapidly melting snow and storms that has led to at least three fatalities. The hardest-hit states include Nebraska, Iowa, Wisconsin, South Dakota and Minnesota.
In Nebraska, flooding has caused estimated damage of nearly $1.5 billion, according to state officials. President Donald Trump approved a disaster declaration Thursday for Nebraska that makes federal emergency funding available to the affected areas.
The severe weather last week included what meteorologists call a "bomb cyclone," or bombogenesis. The event is caused "when a storm rapidly intensifies over a 24-hour period," according to NOAA.
"We expect the flooding will get worse and become more widespread," said Mary Erickson, deputy director of the National Weather Service. "The flooding this year could be worse than anything we've seen in recent years, even worse than the historic floods of 1993 and 2011."
According to NOAA's outlook, "additional rain and melting snow will prolong and expand flooding, especially in the central and southern U.S. As this excess water flows downstream through the river basins, the flood threat will become worse and geography more widespread."
Officials estimated the flooding risk is in areas where more than 200 million people live. Of the total, about 41 million people are at risk for moderate flooding and 14 million more people for major flooding, according to Ed Clark, director of NOAA's National Water Center in Tuscaloosa, Alabama.
"This is potentially an unprecedented flood season," Clark said. "The flooding we have seen in the past two weeks will continue into May and may become more dire in the coming weeks as these waters flow downstream."
Areas with the highest risk for moderate to major flooding include the upper, middle and lower Mississippi River basins and northern Red River areas. In addition, the area at risk includes the Great Lakes, eastern Missouri River, lower Ohio, along with the Cumberland and Tennessee River basins.