Smoke from wildfires in Canada and Idaho barreled into Montana on Monday afternoon, rapidly degrading air quality across the Flathead Valley ahead of a major shift to cold and wet weather.

Monitoring stations showed particulate matter concentrations worsening at around noon Monday as air quality lowered to moderate levels in Libby, Columbia Falls and Kalispell.

"Over the weekend, fires in southern British Columbia exhibited extreme fire behavior," the Montana Department of Environmental Quality's air forecast stated. "The Young Creek fire grew dramatically on Sunday thanks to unseasonably warm air and gusty winds. The smoke plume could be seen on satellite pushing into Northwest Montana." 

Other regional fires affecting air quality included the Big Bear Fire in Idaho near the Bitterroot Valley, and the Garnet Fire east of Missoula.

Weather models suggested a northerly flow on Tuesday would continue to send Canadian wildfire smoke into northern portions of the state. 

However, Northwest Montana's air quality will benefit from a potent weather system that is expected to deliver gusty wind, heavy rain and even mountain snow.

Parts of the region could get drenched with between 1 and 2 inches of rain Tuesday, while low temperatures dip into the mid 40s in the valley and near freezing in the mountains. Localized flooding or mudslides in areas of heavy precipitation is possible, according to the National Weather Service in Missoula.

Wave heights over 4 feet on Flathead Lake could batter east shore locations like Blue Bay and Yellow Bay as winds gust up to 50 mph.

Meanwhile, snow levels in Glacier National Park my dip as low as 8,500 feet, though widespread measurable snowfall is unlikely. Some locations could approach record cool high temperatures for the date. 

"Backcountry users should take into account the cold, wet, and windy conditions to reduce any risk of prolonged exposure or hypothermia," the Weather Service warned.

More seasonable weather returns by the end of the week.