Pierre and Fort Pierre residents woke up to a thick plume of smoke in the air Thursday morning, something Meteorologist Aaron Dorn of the Aberdeen National Weather Service station said is the result of a Canadian cold front combined with wildfires across western North America, including Wyoming.
"The short of it is, if you've noticed for about the past two weeks, when you look up during the daytime hours, if it's no clouds in the sky, the sky's not blue," Dorn said. "It's kind of hazy, milky greyish-white color. That's the smoke from wildfires out in the western U.S. And that's being propagated across the Northern Plains in an elevated fashion. So that's just a layer of smoke aloft, and we haven't been really getting too much of that down to the ground from those fires."
What's changed since Wednesday, Dorn said, is the start of a Canadian cold front.
"One, we're now getting wildfire smoke from Canadian wildfires up to the north of us," Dorn said. "They're streaming down all the way through the southern end of Canada, south-central Canada, all the way down through eastern North Dakota and much of Minnesota and that is now expanding all the way down into northeast South Dakota, even now over to central South Dakota."
Dorn said the latest models show conditions improving some time on Friday.
"It shows widespread coverage of this smoke over South Dakota at two in the morning," Dorn said. "The back edge of it is pushing through Minnesota at that time. So my guess is probably at some point on Friday conditions start to improve."