Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 350 PM EDT Wed Jul 31 2013 Valid 00Z Thu Aug 01 2013 - 00Z Sat Aug 03 2013 ...Wet and unstable conditions along the entire eastern Seaboard... ...Showers and thunderstorms across the Northern Rockies and Northern/Central Plains on Thursday bring a risk for flash flooding and severe weather... It is time to say farewell to the rather pleasant and dry conditions the Mid-Atlantic has been experiencing the past few days. A system over the Southeast U.S. will move across the region on Thursday before lifting into New England on Friday. Scattered showers and thunderstorms are expected to develop across the Mid-Atlantic by late Wednesday and New England by early Thursday. The rain and storms should become more organized and heavier in nature throughout Thursday as the front nears and moves through these regions. The wet weather across the Mid-Atlantic is expected to come to an end Friday morning as the front moves offshore, but should continue across New England as the upper trough swirls over southeast Canada. As the tail end of this system moves slowly over the Southeast, the showers and thunderstorms will remain in the forecast from the eastern Gulf Coast to the Carolinas. A second system stretching across the northern tier of the country will serve as a focal point for convection across the Northern Rockies and Central and Northern Plains states throughout the forecast period. Some of these thunderstorms could have the potential for flash flooding and severe weather on Thursday... especially across the central Plains. Please refer to the Storm Prediction Center for more information regarding the severe weather threat. The northern portion of this system should weaken over the Great Lakes, and redevelop Thursday evening across the Midwest. As this moves through, an organized area of heavy rain and storms is likely to develop across the Middle Mississippi Valley just ahead of the front. Meanwhile, a closed upper low spinning off the West Coast will gradually move inland on Thursday. This will bring an increased chance for scattered shower and thunderstorm activity into the Pacific Northwest and Intermountain West by Thursday afternoon. Monarski Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php