Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 337 PM EDT Sun Sep 06 2015 Valid 00Z Mon Sep 07 2015 - 00Z Wed Sep 09 2015 ...There is a slight risk of severe thunderstorms over parts of Upper Great Lakes/Upper Mississippi Valley... ...Heavy rain possible from the Upper Great Lakes to the Middle Mississippi Valley... A front extending from the Upper Great Lakes/Upper Mississippi Valley roughly southwestward to the Central High Plains will move eastward to the Great Lakes/Central Plains and become quasi-stationary by Monday evening. Showers and thunderstorms will develop along and ahead of the boundary from the Southern High Plains/Central Plains to the Upper Mississippi Valley/Upper Great Lakes that will likewise move eastward to the Great Lakes to the Central Plains and extreme Northern New England by Tuesday morning. Moisture streaming onshore form the Atlantic and later the Gulf of Mexico along with upper-level energy will aid in triggering showers and thunderstorm from parts of the Southern Mid-Atlantic/Southeast Coast to parts of the Central Gulf Coast through Tuesday. In addition, weak monsoonal moisture and daytime heating will produce showers and thunderstorms over parts of the Southern Rockies/Southwest mainly during the late afternoon and late evening hours on Sunday and Monday. Furthermore, onshore flow from the Pacific and upper-level energy will aid in producing rain over parts of the Pacific Northwest into parts of the Northern Rockies through Tuesday. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php