Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 409 PM EDT Tue Sep 02 2014 Valid 00Z Wed Sep 03 2014 - 00Z Fri Sep 05 2014 ...There is a slight risk of severe thunderstorms over portions of the Lower Great Lakes and Central Appalachians... ...Heavy rain possible over parts of the Upper Great Lakes... A front extending from the Northeast southwestward to the Mid-Atlantic then westward to the Southern Plains will move off the Northeast/Mid-Atlantic Coast by Wednesday evening. The western portion of the boundary will lift northward to the Upper Midwest as a warm front by Thursday. Showers and thunderstorms will develop along and near the boundary from the Northeast to the Mid-Atlantic and across the Tennessee Valley to parts of the Southern Plains will likewise move eastward off the Northeast Coast by Wednesday morning. Showers and thunderstorms will remain over parts of the Carolinas into parts of the Central Gulf Coast into Wednesday evening. In addition, upper-level impulses extending from the Southern Mid-Atlantic to the Central Gulf Coast will aid in producing showers and thunderstorms over parts of the Southeast to the Central Gulf Coast Wednesday evening into Thursday. In the meantime, the western end of the front will lift northward as a warm front from the Southern Plains to the Upper Midwest. The boundary will merge with another front moving eastward out of the Northern Rockies on Wednesday evening. Along with the northward moving front, moisture from the Gulf of Mexico will surge northward into the Upper Great Lakes by Thursday morning. The moisture and the lift provided by the boundary will aid in producing showers and thunderstorms over parts of the Middle/Upper Mississippi Valley that will move northward into the Upper Mississippi Valley/Upper Great Lakes by Wednesday into Thursday morning. Meanwhile, upper-level energy over the Pacific Northwest will move eastward to the Northern Plains/South-Central Canada by Thursday. The energy will produce rain over parts of the Pacific Northwest into parts of the Northern Rockies on Tuesday evening into Wednesday morning. The storm will produce an area of light to moderate rain over parts of the Northern High Plains on Wednesday moving into parts of the Northern Plains by Thursday. Showers and thunderstorms will also develop over parts of the Upper Mississippi Valley on Thursday morning. Elsewhere, moisture associated with T. S. Dolly will produce scattered showers and thunderstorms over the Western Gulf Coast through Thursday. T. S. Dolly is forecast to move into the East Coast of Mexico overnight Tuesday. See the latest NHC advisory for the most current track and intensity. Furthermore, upper-level energy off the East Coast of Florida will move westward to the Southern tip of Florida by Thursday. The energy will aid in producing showers and thunderstorms over the area through Thursday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php