Strong-to-severe thunderstorms are expected over the northern and central Plains, Midwest, Northeast and mid-Atlantic.  

VERMONT OFFICIALS URGE FARMERS TO DOCUMENT, REPORT FLOOD-RELATED CROP DAMAGE

The threat of severe storms over the Plains

The threat of severe storms over the Plains on Tuesday (Credit: Fox News)

Large hail, damaging winds, isolated tornadoes and heavy rain could lead to flash flooding.  

The threat of severe storms over the Northeast

The threat of severe storms over the Northeast on Tuesday (Credit: Fox News)

Air quality alerts continue for parts of the Midwest and Great Lakes as smoke from wildfires drifts southward from Canada.  

Potential record high temperatures in the U.S.

Potential record high temperatures in the U.S. on Tuesday (Credit: Fox News)

CLICK HERE TO GET THE FOX NEWS APP 

Heat moving eastward

Excessive heat moving eastward on Friday (Credit: Fox News)

The extreme heat will expand toward the North and across the Mississippi Valley, into the Northeast on Thursday and Friday.