Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 342 AM EDT Tue Aug 13 2019 Valid 12Z Tue Aug 13 2019 - 12Z Thu Aug 15 2019 ...Heat wave abates across the South my mid-week and heavy rain and storms for much of the East Coast... Excessive heat and humidity will continue across much of the south-central U.S. through Tuesday as the upper level ridge leads to subsidence and thus above average temperatures. The combination of the high temperatures and dewpoints well into the 70s will result in dangerous heat indices across these regions, with much of these areas under heat advisories and excessive heat warnings. A cold front is progged to gradually reach the Gulf Coast region by Wednesday night, leading to increased showers and thunderstorms, and temperatures returning closer to seasonal averages. Heavy rainfall and severe thunderstorms will likely make weather headlines from the Mid-Atlantic region to southern New England. A shortwave impulse aloft coupled with a surface low approaching from the Ohio Valley is expected to result in scattered to numerous showers and storms from the Appalachians to the East coast on Tuesday, with the potential for 1 to 2 inches of rainfall for some areas. The best chance for severe weather will be from Tennessee to Delaware, with an Enhanced Risk delineated across parts of Virginia and Maryland. While the heat will eventually be breaking from the south central to southeast U.S. this week, it will building across the Southwest on Tuesday as the upper level ridge builds westward. An Excessive heat warning is in effect for the lower elevations of southern Arizona and southeast California for afternoon high temperatures in the lower to mid 110s and overnight lows only in the middle 80s to near 90 degrees. The hot temperatures across the Southwest are expected to continue through the remainder of this week. Hamrick Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_ndfd.php