Wildfire smoke from Canada is expected to move over the U.S., impacting air quality for millions of people on Friday and this weekend.  Maps and satellite imagery show the large-scale impact of the blazes.

Satellite imagery analyzed by scientists shows that the wildfires are not only extensive but also exceptionally intense, producing towering clouds of smoke that can be transported thousands of miles.

Since the upper Midwest is closest to the fires burning in Saskatchewan and Manitoba, upper-level winds are blowing the thick smoke southward. This has prompted air quality alerts for the entire state of Wisconsin on Friday, as well as parts of Michigan's Upper Peninsula and northern Minnesota.