Jun. 13—An abrupt change in weather is expected next week, with below average temperatures and mountain snow likely.

The shift is forecast to begin late Sunday through Tuesday, according to the National Weather Service in Missoula. A low pressure system will bring widespread precipitation and lowering snow levels across Western Montana.

Snow levels could drop to 4,500 feet, potentially damaging trees and other vegetation from snow loading.

One to 2 feet of snow is possible over the high terrain of Glacier National Park above 6,000 feet — including Logan Pass on Going-to-the-Sun Road. The alpine section of the Sun Road remains closed to vehicle traffic.

The Weather Service advises people to be prepared for unpleasant and raw conditions in the backcountry next week.

Rain is likely in the Flathead Valley Monday through Wednesday. Highs will top out in the upper 50s with lows in the 40s.

Rivers are not expected to rise during this period, with the Flathead River at Columbia Falls forecast to stay between 8 and 9 feet. Flood stage is 13 feet.

Mountain snowpack remains robust in Northwest Montana. About 42 inches of snow remained on the gound at Noisy Basin in the Swan Range, holding a snow-water equivelant that’s 125% of normal.

A weather station on Flattop Mountain in Glacier National Park on Thursday showed 38 inches of snow on the ground.

Overall, the Flathead Basin snowpack is 70% of normal for this time of year.