With up to six inches of high-elevation rain in the forecast, the National Weather Service on Monday issued a flood watch for portions of Northwest Montana through Wednesday afternoon.

The flood watch covers the West Glacier area and the Kootenai/Cabinet area but excludes the Flathead Valley.

The Flathead and Mission valleys will likely see only up to one inch of rain, with two to four inches forecast in the mountains to the north and east.

The Cabinet Mountains should see the largest impacts this side of the Idaho border, with up to half a foot of rain falling during the next two days.

“Our alert level isn’t at its highest, but Libby, the Yaak, Troy and Noxon, they’re going to see a lot of rain and a lot of snow melt,” LeeAnn Allegretto, a meteorologist at the Weather Service’s office in Missoula, said Monday. “The fact that they have streams and creeks and rivers running through them, that could contribute to them seeing more problems.”

She expected melting snow to significantly contribute to flooding while warm, Pacific air is forecast to push the snow level as high as 7,000 feet.

Tuesday’s high temperature is expected to hit 48 degrees in Kalispell and 44 degrees in West Glacier, with Tuesday night low temperatures near 40 degrees.

The forecast for the summit of Big Mountain (elevation 6,790 feet) calls for a high of 35 degrees Tuesday, with snow turning to rain at Whitefish Mountain Resort. Tuesday night’s low is forecast at 30 degrees atop Big Mountain.

The lower-mountain forecast predicts a high of 40 degrees and low of 37 degrees Tuesday. Whitefish Mountain Resort opened its ski and snowboard season on Saturday.

Allegretto added that while the rain event should taper off by Wednesday afternoon, flooding could linger for up to 24 hours afterward.

“We are expecting a widespread cool-down, and that should slow things pretty dramatically,” she added.

Reporter Sam Wilson can be reached at 758-4407 or by email at swilson@dailyinterlake.com.