Snowpack in the Kootenai River Basin climbed from 121 percent to 138 percent of average during that same period, while the Upper Clark Fork River Basin moved from 113 percent to 125 percent of average. The Bitterroot River, which Nickless initially thought would avoid flooding, went up from 103 percent of average to 118 percent.

Nickless said his figures measure snow water equivalent, or the amount of water the snowpack contains.

Some areas in the Flathead River basin, such as Bisson Creek and Noisy Basin, are registering nearly twice the amount of water contained in a normal winter's snowpack.

Data-gathering instruments at a site in Noisy Basin, which is at an elevation of 6,000 feet, currently register 67 inches of water in the snowpack. In a typical year, there would only be about 40 inches of water, Nickless said.

"That water has to go somewhere," he said. "Even if it melts slowly it will exceed the banks of the river and do some flooding."

Nickless said with the Flathead River expected to reach levels of 14.1 to 15.8 feet, he expects "just about every Flathead River location to flood. And that's just with snow melt."