Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 442 AM EDT Sun Apr 06 2014 Valid 12Z Sun Apr 06 2014 - 12Z Tue Apr 08 2014 ...Severe thunderstorms and widespread flash flooding expected across the Central Gulf Coast states on Sunday... An expansive area of showers and thunderstorms will continue to develop to the north of a frontal boundary stretched across the northern Gulf and up through the southeastern U.S. on Sunday. A surface wave along the front is expected to strengthen while it lifts into the Lower Mississippi Valley Sunday afternoon...and an abundance of moisture getting transported out of the Gulf will fuel an organized area of heavy rains...with embedded thunderstorms...across the Central Gulf Coast states. Severe weather and widespread flash flooding will both be a threat across the region. The heavy rains and thunderstorms will begin to spread northward up the Eastern U.S. as the intensifying low lifts through the Tennessee and Ohio Valleys on Monday and into the Lower Great Lakes by early Tuesday. The widespread threat for flash flooding should diminish...but severe weather will still be a possibility within developing storms ahead of the trailing cold front sweeping through the Southeast and southern Mid-Atlantic states. Scattered shower activity is expected beneath a broad upper trough swinging out of the Rockies on Sunday. Although temperatures will be low enough to support snow in the higher elevations...a lack of moisture will limit precipitation totals and snowfall accumulations. Light rain and snow showers will be possible across the northwestern corner of the Country early Sunday...but then a ridge building in aloft should keep locations west of the Continental Divide precipitation free for the start of the work week. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php