Heavy smoke expected to linger above western Montana

HELENA (AP) — Smoke from wildfires across the U.S. West has wafted over large swaths of western Montana on Friday, leading to unhealthy air quality in Missoula and Frenchtown.

The Montana Department of Environmental Quality recommends that active children, adults and people with asthma and other respiratory diseases avoid prolonged outdoor exertion amid unhealthy air quality.

Conditions were classified as unhealthy for sensitive groups in Helena, Great Falls, Cut Bank, Seeley Lake, Hamilton, Butte and Bozeman, where the department recommends limiting outdoor exertion for sensitive groups.

Dense smoke from wildfires in Oregon is causing poor air quality in Montana, said Leeann Allegretto, meteorologist with the National Weather Service. She said the smoke is expected to linger at least through the weekend, with visibility ranging from 3 to 6 miles (5 to 10 kilometers) in Missoula.

With large fires burning in British Columbia, California, Oregon and Idaho, Allegretto said she did not expect a major reprieve from smoky skies above Missoula in the coming days, even with storms expected to move into the area next week.

Missoula could also experience above-average heat this weekend, with temperatures possibly exceeding 100 degrees Fahrenheit (38 Celsius), though heavy smoke could keep the air from reaching full heat potential.

Climate change has made the West much warmer and drier in the past 30 years, and scientists have long warned that the weather will get wilder as the world warms. Special calculations are needed to determine how much global warming is to blame, if at all, for a single extreme weather event.

Meanwhile, extreme fire risk remains in much of Montana.

The Alder Creek Fire has burned more than 5 square miles (13 square kilometers) west of Butte, leading to the evacuation Thursday of all 17 homes in Alder Creek, NBC Montana reported.