(AP) — A push of slightly cooler and less humid air will cause the dome of heat that has been so persistent in much of thee eastern two-thirds of the nation to shrink southward today.
Showers and thunderstorms will be a focusing point along the boundary of the two batches of air from the central Plains to the Ohio Valley and southern Appalachians. Some of these areas, especially those east of the Mississippi River, can be prone to flash flooding.
Farther northwest, a second push of cool air will set off showers and thunderstorms over parts of the northern Plains and Upper Midwest.
Meanwhile, tropical moisture is forecast to trigger multiple rounds of showers and thunderstorms over the interior Southwest, where flash flooding will also be a concern.
A major heat wave will grip the Northwest through this week.
The tropics remain quiet, with no forecast storm development for the next few days.