The National Weather Service has issued an air stagnation advisory for much of western Montana until midday Wednesday.
Following last week’s cold snap and winter storm, a high-pressure system is moving into the region, which will result in light winds and the development of inversions. The Weather Service has issued the stagnation advisory for all of northwest Montana, as well as the Missoula and Bitterroot Valleys.
Stagnant conditions can trap pollutants near the surface and cause deteriorating air quality. The American Lung Association said people with respiratory illness should keep an eye on the forecast and avoid outdoor exercise or strenuous activity when air quality is bad.
Find real-time air-quality information from the Montana Department of Environmental Quality.
