Weather forecasters say next week could be the start of the long anticipated La Nina weather pattern. The first big winter storm of the season is predicted, and the mountains of Western Montana could see anywhere from four to seven feet of snow by Jan. 19, the National Weather Service in Missoula reported today.

A cold front will move through the region Saturday night, bringing moderate snow to mountain passes, especially Marias Pass near Glacier National Park. The Flathead Valley could pick up four or more inches.

On Tuesday to Thursday, a very moist westerly flow is expected to set up, likely bringing heavy snow to area mountains. Several feet of snow could fall in Glacier National Park. Arctic air will enhance snow in the valley, and gusty winds of 40-50 mph are predicted.

Backcountry travelers should be prepared for changing snowpack characteristics following this snow event, the National Weather Service warns.

"It looks like the start of La Nina," NWS meteorologist Ryan Leach said. "The long term forecast is still for above average precipitation and below average temperatures."