Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 450 PM EDT Fri Aug 08 2014 Valid 00Z Sat Aug 09 2014 - 00Z Mon Aug 11 2014 ...Heavy rains and flash flooding possible over the Southern Appalachians... Showers and thunderstorms will continue to focus along a wavy frontal boundary stretched from Oklahoma to the Southeast coast this weekend. Storms developing within a warm and muggy airmass in place to the south of the front could contain locally heavy downpours. A more organized area of heavy rains is expected to develop over the Southern Appalachians as a surface low along the front slowly meanders eastward through the Tennessee Valley. These rains could pose a risk for flash flooding. Well north of the wavy boundary...locations from the Great Lakes to the Northeast should be in store for a pleasantly dry weekend. A cold front in the northern tier will trigger scattered showers and thunderstorms while dipping through the Northern Plains Friday night into Saturday. More organized areas of convection will be possible as the boundary pushes farther southeastward through the Upper Midwest and Central Plains Saturday night into Sunday. Monsoonal moisture lingering over the Great Basin will continue to foster scattered shower activity this weekend. Late in the forecast period...temperatures will be on the rise again across portions of the Northwest as an upper ridge builds in aloft. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php