Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 431 AM EDT Fri Jun 27 2014 Valid 12Z Fri Jun 27 2014 - 12Z Sun Jun 29 2014 ...Heavy rains with strong to severe storms possible across portions of the Great Plains and Mississippi Valley... ...Showers and thunderstorms will continue across the southeastern quarter of the Nation... Numerous showers and thunderstorms are expected to breakout ahead of a cold front edging eastward across the Northern and Central Plains on Friday. A rich supply of moisture...combined with the slow progression of the system...will pose a risk for heavy rains and flash flooding; However...the main threat will be widespread severe weather. By Saturday...the chance for heavy rains and strong to severe storms should shift slightly eastward with the front...impacting locations across the Upper to Middle Mississippi Valley. Widespread convection will continue to ignite within a warm and unstable airmass in place across the southeastern quarter of the Nation. Much of the activity should be scattered in nature...but a frontal boundary sagging southward along the Eastern Seaboard could help focus storms across the Carolinas. Also...energy moving through aloft could help organize activity from the Western Gulf Coast to the Tennessee Valley. Persistent onshore flow will keep weather unsettled from the Pacific Northwest to the Northern Rockies the next few days. Precipitation should be light to moderate...with the highest totals expected along the favored slopes of the terrain. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php