Weather across America

(NATIONAL) Dangerous heat grips parts of the South, Excessive Rainfall leading to flash flooding possible from the Tennessee Valley to the Southeast, and slow-moving shortwave energy will support scattered showers and thunderstorms across the Mid-Atlantic, Southeast and Gulf Coast. 

Heavy rain may develop over the Carolinas, where favorable dynamics moisture and instability will be present. Therefore, a Slight Risk of Excessive Rainfall leading to Flash Flooding is in effect over portions of western Tennessee and the Carolinas. Widespread areas of 1-2 inches are likely with locally higher amounts possible Sunday. 

The focus for excessive rainfall shifts to a stationary front draped across the Southeast and Gulf Coast on Monday. The axis of heaviest rainfall will occur from the Great Smokey Mountains of North Carolina down through northern Georgia and to the central Gulf Coast. Another Slight Risk of Excessive Rainfall is in effect from the western Carolinas down into northern Georgia and northwestern Alabama. 

Elsewhere, scattered showers and thunderstorms will form across the High Plains through Monday supported by shortwave energy that is embedded within the western U.S. ridge. A dangerous heat wave will persist across portions of the southern U.S. through Monday. Record high temperatures combined with unusually high humidity will lead to heat indices near record levels over the Mid-Mississippi Valley and Gulf Coast region.

The extreme heat and lack of overnight relief will continue for the Gulf Coast until a cold front ushers in more seasonal temperatures beginning Monday. Portions of the Northwest and Desert Southwest will experience abnormally warm temperatures over the next couple of days as well as the upper ridge focuses over the West. 

Excessive Heat Warnings and Heat Advisories are in effect for the Gulf Coast and Desert Southwest. Heat of this intensity poses a health risk to anyone without effective cooling and/or adequate hydration. Do not underestimate the potential for heat-related illness. Have a way to break your heat exposure, cool down, and stay hydrated.