Canadian wildfire smoke shifts into the Midwest and Northeast, prompting health warnings

Smoke from large Ontario and Minnesota wildfires is forecast to drift into the Midwest, Northeast and Mid-Atlantic through Friday, likely worsening air quality and triggering advisories to limit outdoor activity, keep windows closed, and run air conditioning with clean filters; the plume is expected to move south and east with light winds, with Minnesota declaring a peacetime emergency to aid firefighting efforts.