Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 456 PM EDT Wed Aug 06 2014 Valid 00Z Thu Aug 07 2014 - 00Z Sat Aug 09 2014 ...Heavy rains and flash flooding expected across the Middle Mississippi Valley... Showers and thunderstorms will continue to fire up along and north of a frontal boundary stretched through the Nation's midsection Wednesday into Thursday. An abundance of Gulf moisture feeding into the storms will allow for periods of heavy rains. The greatest risk for any flash flooding will be across the Middle Mississippi Valley...where a surface wave along the boundary should help develop an organized area of heavy rains with embedded thunderstorms. As the wave of low pressure steadily tracks eastward Thursday night into Friday...the threat for heavy rains and flash flooding will shift into portions of the Ohio Valley. A wavy front draped over the Mid-Atlantic states will serve as a focal point for convection Wednesday night...but the boundary should push southeastward off the Atlantic coast on Thursday and leave behind drier conditions for the end of the work week. South of the front...plenty of moisture and daytime heating will keep convection in the forecast across Florida. Farther north...energy swinging through aloft should allow for scattered showers and thunderstorms over New England. Out West...the combination of moisture and slow moving energy aloft will trigger additional days of showers and thunderstorms over the Great Basin and Central/Southern Rockies. Gerhardt Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php