To the south and east of the boundary, hot and humid air will bake the Southeast and spread northward into the mid-Atlantic.
Strong, gusty thunderstorms will erupt late in the day in parts of the western Plains, while dry and pleasant conditions grace the Upper Midwest and Great Lakes region.
Hot and dry air will continue to enhance the threat for wildfire development and spread in the Four Corners region.
A storm system diving into the Pacific Northwest will bring showers and much cooler weather back to the region. Ahead of the system, scattered thunderstorms will dot the northern Rockies.
DAILY EXTREMES
National High Tuesday 103 at Needles, CA
National Low Tuesday 24 at Aspen Springs, CO