Kalispell residents looking east could see only the dim outline of the Swan Mountain range Wednesday as smoke from wildfires in the Pacific Northwest spilled into the Flathead Valley — a trend expected to continue today.

The conditions prompted the Montana Department of Environmental Quality to label the valley’s air quality “unhealthy for sensitive groups,” meaning people with respiratory or heart disease, the elderly and children should avoid prolonged outdoor exertion until the advisory is lifted.

Kristin Martin, a state air quality meteorologist, said Wednesday was the first time this year the valley has reached that threshold for a 24-hour average, although the shorter-lived smoke plume when the Glacier Rim Fire initially flared up had caused average air quality to dip to that level over an eight-hour period.

“Right now, it’s a pretty bland weather system, so the smoke is just drifting in from the west and northwest directions,” Martin said. “Toward the weekend, there will be more of a southwesterly flow and a better chance of showers and thunderstorms that will potentially clear it out and cause some improvement.”

National Weather Service meteorologist Dan Zumpse agreed but characterized the shift in wind from northwesterly to southwesterly as a potential “double-edged sword” that could bring smoke in from wildfires burning in California and the Southwest.

“I think the big thing that’s really going to get the smoke out of the air in the next couple days will be the pattern change with more water-bound thunderstorms we’re expecting,” Zumpse said, “especially considering how dry we’ve been for the last month. A lot of this can also be attributed to suspended dust and dirt in the air.”

Scattered thunderstorms could begin Friday afternoon and continue through the weekend and into next week, according to the Weather Service forecast. Flash flood warnings are in effect throughout Western Montana’s southern half, but Northwest Montana is unlikely to see the same level of precipitation.

“But that’s not to say that shouldn’t be a concern for people up there, considering how long it’s been since we’ve had any real precipitation,” Zumpse said.

The Glacier Rim Fire, 95 percent contained, is currently in mop-up stage and not contributing to air quality conditions.

However, at least 10 significant wildfires in Washington state were burning more than 21,000 acres as of Wednesday afternoon, combining with smoke plumes from more than 104 significant wildfires in British Columbia.

Smoke from both Washington and British Columbia is being funneled into Northwest Montana.

The Weather Service is predicting some relief this morning, but shifting winds will return smoke to the valley by this afternoon, with more directly westerly winds blowing over several wildfires burning in the Idaho Panhandle.

In the longer term, this could just be the start of a relatively smoky summer.

“Smoke impacts will likely continue for the foreseeable future,” Martin said. “The season has certainly been very intense to start off with, so I would expect that to continue.”

Despite a quarter-inch of precipitation falling Tuesday on the Flathead Valley, Stage 1 fire restrictions are still in effect for Flathead, Lake, Lincoln and Sanders counties. Fires are prohibited except within designated recreation sites.

Exceptions include liquid petroleum or LPG fires, or within the Bob Marshall Wilderness Complex, where campers may only use completely contained wood stoves with fire screens or spark arresters.

Smoking is only allowed in buildings, vehicles or outdoor areas cleared of flammable materials. For complete list of recreation sites where campfires are permitted, visit firerestrictions.us.

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