Dangerous wildfire smoke is impacting more than a dozen states on Saturday morning as air quality alerts span from the Upper Midwest and Great Lakes to New England, south through the Northeast and Mid-Atlantic.
More than 900 wildfires are burning across Canada, sending smoke into the Northeast and Mid-Atlantic, though a storm system moving through Saturday could help clear much of the haze.
Ontario Premier Doug Ford visited Thunder Bay on Saturday to receive an operational briefing and highlight the province's ongoing firefighting efforts.
In a post on X, Ford outlined the extensive resources being deployed to combat wildfire, including hundreds of firefighters, aircraft, helicopters, heavy equipment and incident management teams.
He emphasized that Ontario continues to work closely with Indigenous communities, emergency management partners and other jurisdictions to protect lives and contain the fires.
Air Quality Alerts remain in effect from Minnesota to Maine this afternoon, including Chicago, Detroit, D.C., Philly, New York City and Boston. Most alerts in the Northeast will expire by midnight.
Parts of the western Great Lakes and Upper Midwest are expected to see poor air quality through the weekend as northwesterly winds push a plume of smoke into the region.
The Northeast will see a big improvement in air quality during the second half of the weekend, according to the forecast.
A system sweeping across the Northeast this afternoon will quickly push the wildfire smoke to the north with improving conditions expected for much of the region by the evening hours.
The region will see a huge improvement on Sunday with most of the smoke clearing.
Plumes of lighter smoke could still sweep across parts of the region throughout the day. However, it will be focused higher up in the atmosphere and just bring slightly hazy skies in some areas.
Meanwhile, 100 million Americans from Illinois to the East Coast are on alert for severe thunderstorms and flash flooding.
The Storm Prediction Center has issued a Level 3 of 5 risk for severe storms across parts of the Ohio Valley, Northeast and Mid-Atlantic. Major cities along the Interstate 95 corridor, including New York, Philadelphia, Baltimore and Washington, D.C., could be affected.
Pittsburgh, Cleveland and Buffalo are also expected to see strong storms.
The rounds of showers and storms will bring the threat of damaging winds, hail, a few tornadoes and chances for flash flooding in certain areas.
Flood watches are in effect for parts of the Northeast, including New York City, Philadelphia and Washington, D.C. through Saturday evening as heavy rainfall could trigger flash flooding.
Elsewhere, monsoonal moisture in the Southwest could fuel another round of thunderstorms capable of producing heavy rainfall and flash flooding extending from West Texas and New Mexico into central and northern Arizona and southern Utah.
On Sunday, severe weather is possible across parts of Virginia and the Carolinas, where scattered storms could produce damaging winds and heavy rainfall as Charlotte, Raleigh and Virginia Beach are among the cities that could be affected.
ABC News' Michelle Simmons contributed to this report.
