Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 431 PM EDT Sun Jul 20 2014 Valid 00Z Mon Jul 21 2014 - 00Z Wed Jul 23 2014 ...Heat and humidity make a return to the central U.S. early this week... ...Flash flooding and severe thunderstorms possible across the Northern Plains and Upper Mississippi Valley... ...Wet and stormy conditions will continue over the Southeastern U.S.... Temperatures and dewpoints will be on the rise beneath an upper ridge building in over the Central U.S. early this week. Heat advisories have been issued for portions of the Midwest where heat indices could climb into triple digits. To the north of the expanding ridge...a cold front will begin to drop south/southeastward through the northern tier of the Nation. The front will trigger showers and thunderstorms while pressing through the Northern Plains Monday night and crossing into the Upper Mississippi Valley on Tuesday. These developing storms will be tapping into a warm and unstable airmass setting up over the central U.S....giving them the chance to become organized and potentially pose a threat for flash flooding and severe weather. Scattered showers and thunderstorms will be possible with the tail end of the boundary while it settles southward through the northern Great Basin and Rockies. Wet and stormy conditions will persist across the Southeast and up into the Central Appalachians Monday into Tuesday...beneath an elongated upper trough stretched over the Eastern U.S.. Much of the shower and thunderstorm activity should be scattered in nature; however...a lingering frontal boundary...combined with a rich moisture supply...could lead to organized areas of heavy rains along the Central Gulf Coast...across Florida...and over portions of Georgia and South Carolina. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php