The haze you see in the sky over the Cumberland Plateau today will actually be smoke, drifting down from massive wildfires that are burning more than 1,500 miles away.
The National Weather Service’s forecast for Scott County over the next two days is for haze. That haze is created from smoke hovering relatively close to the ground from the hundreds of wildfires that are burning in Canada, and the dozens more that are impacting the Pacific Northwest in the U.S.
Wildfires have created states of emergency in both nations, after several weeks of heat and drought. The same weather conditions that have led to a somewhat cooler-than-normal and wetter-than-normal summer in the Southeast have generated just the opposite effect for other parts of North America to the north and west.
One of the most severe wildfires, the Bootleg Fire in Oregon, is so strong that it has generated its own weather, creating lightning strikes and releasing billows of smoke. The smoke from all the wildfires has created health hazards across parts of North America for more than a week, and on Tuesday that smoke began to filter as far south as Tennessee.
For the next couple of days, the smoke in the air is expected to thicken over the Cumberlands and most areas north of Interstate 40, which will generate hazy conditions and lower air quality while hampering visibility.
So far, the National Weather Service has not issued any air quality alerts for the Cumberland Plateau region. That has not been the case for other parts of the country, including Middle Tennessee, where a Code Orange air quality alert is in place over the Nashville area. In a Code Orange alert, health officials warn that active children and adults, and people with respiratory diseases such as asthma should limit prolonged outdoor exertion.
Other places with air quality alerts include most of Minnesota, much of Indiana and a portion of upper East Tennessee and southwestern Virginia.
Red flag warnings remain in place across parts of the interior of the Pacific Northwest, including Washington, Oregon and Idaho. Fire weather watches are in place for other swaths of the northern Rockies, extending as far south as central California.
The atmospheric setup that is ushering the smoke from the wildfires southward is the same setup that has lowered rain chances in East Tennessee after two weeks of almost daily thunderstorms.
Often times, particularly during the summer months, the air flow pattern over East Tennessee is from the south, ushering in warm, moist air from the Gulf of Mexico. If that were the case this week, thunderstorm chances would be greater, while smoke from the northern wildfires would be pushed the opposite direction, away from Tennessee.
Instead, a northwest flow pattern is in place, due to atmospheric ridging over the center of the continent. Such a flow leads to warmer and more sunny conditions in this part of the country.
East Tennessee’s location on the eastern periphery of the ridge of high pressure in the upper atmosphere also creates a condition known in meteorological circles as “subsidence,” where air sinks over a broad area. That will bring smoke from the wildfires closer to the surface and make it even more evident. However, the greatest impact in East Tennessee is likely to be felt in the Tri-Cities area.