Spring forecast calls for major or moderate flooding in 25 states

March 21 (UPI) -- This spring promises to be a wet one for the majority of the continental United States with major or moderate flooding potential in 25 states, the National Oceanic and Atmospheric Administration reported Thursday.

Nearly two-thirds of the United States is at an elevated risk of flooding.

Residents in Nebraska have already dealt with unprecedented flooding that's caused more than $1 billion in damage that covers 80 percent of the state. Other northern Midwest states are also affected.

"The extensive flooding we've seen in the past two weeks will continue through May and become more dire and may be exacerbated in the coming weeks as the water flows downstream," said Ed Clark, director of NOAA's National Water Center in Tuscaloosa, Alabama. "This is shaping up to be a potentially unprecedented flood season, with more than 200 million people at risk for flooding in their communities."

The flood risk is based on current snowpack, soil moisture, frost depth, streamflow and precipitation.

Ice jams are also a problem as sheets of ice break apart, creating an artificial dam that causes rivers to go over their banks.

"Additional spring rain and melting snow will prolong and expand flooding, especially in the central and southern U.S.," NOAA said. "As this excess water flows downstream through the river basins, the flood threat will become worse and geographically more widespread."

Areas at the greatest risk for flooding are the entire Mississippi River basin, the northern Red River basin and the Great Lakes regions. The eastern Missouri, lower Ohio, lower Cumberland and Tennessee basins are also at risk.

It's not all bad news, though -- above-average rains this winter means California has ended its seven-year drought.

Drought conditions will continue in northern New Mexico, though spring storms and melting snow will help relieve the drought. The drought will persist in Alaska and Oregon and could expand to Hawaii this spring.

North Texas to the Dakotas could have below-average temperatures this spring.