Cool weather may delay expected flooding on area rivers

The service’s online hydrographs showed predictions of some area rivers rising to near flood stage levels this weekend.

“I don’t think we’ll see that,” Weather Service hydrologist Ray Nickless said.

However, when a period of sustained warmer temperatures settles in, Nickless expects runoff from low-elevation drainages to cause flooding.

“I see high water coming out of the Ashley Creek drainage. I expect that to get to flood level,” he said, and he expects the same for the Fisher, Little Bitterroot and Thompson river drainages.

Once snow starts to melt at higher elevations, he anticipates other rivers, includes the three forks of the Flathead River system, to be running high.

Mountain snowpack above the Flathead Basin is at 131 percent of average. Above the Kootenai Basin, it is at 125 percent of average.

Nickless is forecasting small stream flooding on the eastern and western slopes of the Mission Mountain range.

An automated snow measurement site at Bisson Creek at 4,900 feet is at 183 percent of average, and another site at 6,700 feet is at 151 percent of average.

The Noisy Basin site on the Swan Range is at 151 percent of average, with an unusually high snow water equivalent of 62 inches.

Nickless said snow water equivalents have been rising across the region because of recent rain being absorbed by the snowpack.

“That’s got to come out at some point,” he said.