Photos: Extreme Canadian wildfire smoke shrouds parts of U.S.

The National Weather Service has issued several air quality alerts today. Smoke from wildfire in Canada, including dozens of blazes in Quebec, is flowing south. There are alerts up in the Northeast, along the mid-Atlantic and as far south as North and South Carolina. There are air quality alerts in parts of Ohio, too.

For the past several weeks, smoke from the wildfires have been pushing into the U.S. Here are some scenes from around the U.S and Canada.