Severe thunderstorms were expected across swaths

Across swaths of the Eastern U.S. on Monday

Southwest continued to swelter under

A relentless heat wave through the long Fourth of July weekend

Scattered showers and thunderstorms were expected

Through much of the eastern U.S., with chances of flash flooding

In some areas from the lower Great Lakes to southern New England

The National Weather Service said in an update Monday

There was also a lower possibility of heavy rain and thunderstorms

Meanwhile, a cold front slowly pushing into the Ohio Valley  was expected to deliver drier and cooler air toward the East Coast