Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 455 PM EDT Sun Apr 27 2014 Valid 00Z Mon Apr 28 2014 - 00Z Wed Apr 30 2014 ...High impact flash flooding and severe weather event expected ahead of a slow moving system moving out of the Plains... ...Conditions will dry out and warm up out West as a strong ridge begins to build in aloft... A cold front slowly moving out of the Plains...combined with return flow from the Gulf of Mexico...will set the stage for a widespread flash flooding and severe weather event across the Mississippi and Tennessee Valleys early this week. The copious amounts of moisture surging northward out of the Gulf will fuel an expansive area of moderate to heavy rains ahead of the this system...and the slow progression of the storm will make flash flooding a serious concern. Given the large amounts of instability that will be available...thunderstorms developing with this system will likely become strong to severe. Locations across the middle to lower Mississippi Valley will be under the greatest risk Sunday night into Monday...and the threat will only slightly shift eastward into the Tennessee Valley and portions of the Southeast Monday into Tuesday. Another facet of this storm will be with precipitation developing within the cold air on the back side of the deep surface low gradually lifting out of the central Plains. Temperatures should be low enough to support late season accumulating snows across portions of the northern High Plains. Scattered rain and snow showers should continue behind a dissipating cold front pushing farther inland through the northwestern corner of the Country Sunday night; However, conditions will dry out and temperatures will be on the rise out West as a strong ridge begins to build in aloft on Monday. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php