MISSOULA - It was a cold, sunny day across Western Montana, but we’re already seeing the indicators of stagnant air conditions developing as we end the week.
After a cold and clear morning across the region Wednesday morning, the first indicators of problems to come started to show up in many of our valleys.
While persistent light winds had been helping the past couple of days, by late Wednesday morning you could see the haze starting to build, as high pressure strengthens over the region, trapping cold air in the valley floors. That means particulates from a variety of sources, including cars, doesn’t have a chance to disperse.
Montana DEQ says air quality was still “good” Wednesday afternoon, although Libby was registering “moderate” conditions. Our forecast is for those conditions to continue to deteriorate as we approach the weekend.