Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 333 AM EDT Wed Aug 27 2014 Valid 12Z Wed Aug 27 2014 - 12Z Fri Aug 29 2014 ...The flash flood threat continues for portions of the Central Plains through Thursday morning, and moves into the Midwestern states by Thursday afternoon... ...A slight risk for severe thunderstorms is possible for parts of Nebraska and Kansas on Wednesday... Tropical moisture lifting into the Four Corners region of the Country will interact with an area of upper level energy advancing eastward across the Central Rockies. This is expected to continue to produce an expansive area of showers and thunderstorms from the Central/Southern Rockies to the Midwest on Wednesday and Thursday. The heaviest and most organized of the convective activity is expected to ride along a nearly stationary surface boundary stretched across the Central Plains and Middle Mississippi Valley. For Wednesday into Thursday, WPC has highlighted a slight risk for flash flooding across much of central and eastern Nebraska into western Iowa. In addition, SPC has also highlighted a slight risk for severe weather for southern Nebraska and Northwest Kansas. As the energy aloft ejects into the Central Plains on Thursday, and the surface front lifts slowly northward, the heavy rain and flash flood threat will move into the Middle Mississippi Valley and portions of the Upper Midwest. Meanwhile, the eastern portion of the this boundary will move east and southward as a cold front across the Northeast, Mid-Atlantic, and Ohio Valley on Wednesday. This should produce scattered showers and storms along the front, but given the lack of upper level support, the activity should remain fairly light and mainly driven by diurnal heating. Down south, weak energy moving westward into coastal Texas will bring showers and storms to portions of the Western Gulf Coast region throughout the forecast period. While the heaviest of the rain is expected to remain offshore, a few scattered showers or thunderstorms will likely make it onshore to coastal regions of Texas and Louisiana. Monarski Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php