A heat wave will continue to keep much of the Eastern United States in its grip Sunday, while a cold front that could lower temperatures in the middle of the country may be accompanied by thunderstorms that threaten flash floods.
The National Weather Service says the "oppressive and dangerous" heat wave will abate by Monday and Tuesday. The agency says the greatest heat threat is in the Carolinas up to Maine, where temperatures will feel like 100 to 110 degrees Fahrenheit.
Temperatures are expected to remain at or above the high 70s overnight.
Inland, a cold front stretching between the Central Plains and the Great Lakes region is forecast to move south, carrying showers and thunderstorms that could bring heavy rainfall and flash flooding to the Midwest.