Smoke from wildfires raging in California and the Rocky Mountains will linger over the Black Hills through the week, the National Weather Service said Tuesday.
Meteorologist Steve Trimarchi said Tuesday that a ridge of high pressure over the Rockies has been funneling the smoke to the Black Hills for the past several days.
"The flow aloft is from the west and southwest and that happens to be where all the large fires are in California, Idaho, portions of Montana and Wyoming," Trimarchi said. "Most of the large fires are in California, and the way the pattern is working right now, that is blowing all of that smoke into our area."
The smoke particulates flowing from those large wildfires are impacting air quality throughout the Black Hills. The South Dakota Department of Environment and Natural Resources has four recording stations in the area at Rapid City, Black Hawk, Wind Cave National Park and Badlands National Park.
According to the DENR's readings, the air quality index (AQI) in the Black Hills has hovered in the moderate category since the middle of last week. The AQI's moderate value is between 50 and 100.
Tuesday, the Rapid City AQI monitoring station rose to a high of 90. The DENR's moderate criteria states the air quality is acceptable, but there may be a moderate health concern for a small number of people who are unusually sensitive to air pollution.
Trimarchi, who works in the Rapid City office, said the air pattern is expected to last until a Canadian air mass moves through the area over the weekend.
"Luckily, the smoke is staying in the upper atmosphere for the most part, so we're not really getting the smell or the more irritating parts of it," he said. "It's going to stay this way for the next two to three days, but we will have fluctuation in how hazy it is outside. The real change where the smoke should begin to dissipate is after Friday when the upper air mass changes."
Until then, guidelines from the U.S. Environmental Protection Agency say people who are sensitive to the smoke particulates should take precautions.
"This is especially important if you have heart or lung disease and are at higher risk for adverse health effects," the EPA guidelines state. "Reducing physical activity and using HEPA-filtered air cleaners indoors are other ways to reduce your smoke exposure."
Contact Assistant Managing Editor Nathan Thompson at firstname.lastname@example.org.
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