This week’s deluge of rain is projected to bring rivers and streams to new peaks this year across Northwest Montana, and people in flood-prone areas are being advised to be prepared.

Flathead, Lincoln and Lake counties were under flood watches through Thursday afternoon, with total rainfall of up to 3 inches expected by Thursday.

Kalispell set a new precipitation record on Tuesday. By 9 p.m., 1.72 inches of rain had fallen at Glacier Park International Airport. The previous record for June 17 was 1.13 inches set in 2010.

Higher elevations also may receive from 15 to 20 inches of snow. It was snowing heavily on U.S. 2 over Marias Pass on Tuesday afternoon.

“These impressive precipitation totals will result in significant runoff which may cause rapid rises on area small streams, creeks and culverts,” an advisory from the National Weather Service states. “Many streams may approach bank-full, and some local flooding will be possible, especially on those streams and creeks flowing out of Glacier National Park.”

The Flathead River at Columbia Falls is expected to exceed its previous peak for this year’s runoff season.

The river is predicted to rapidly rise by over four feet, reaching nearly the 14-foot mark, which is considered minor flood stage. It is expected to gradually drop over the following few days.

Other rivers in the Flathead Valley— the Whitefish, Stillwater and Swan rivers — are expect to approach their flood-stage flows.

In Lake County, small streams and creeks flowing from the Mission Mountains might spill over their banks, according to the Weather Service.

“Lowland flooding and significant ponding on area roads from Libby to Kalispell and Glacier Park is expected at times,” the Weather Service advised.

Ray Nickless, a hydrologist with the National Weather Service, said the saving grace is that lower temperatures have prevailed at elevations above 6,000 feet, causing snowfall and limiting snow melt that would add to the rain runoff at lower elevations.

While the seemingly constant rainfall may seem as if it would rival heavy rains that fell prior to the historic 1964 floods, Nickless said the biggest difference is the lack of rain at high elevations this week.

“In 1964, it was all rain,” he said.

Reporter Jim Mann may be reached at 758-4407 or by email at jmann@dailyinterlake.com.