Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 320 AM EDT Sun Jun 19 2016 Valid 12Z Sun Jun 19 2016 - 12Z Tue Jun 21 2016 ...There is a slight risk of severe thunderstorms over the Upper Mississippi Valley... A front extending from the Northern Plains to the Central Rockies into the Great Basin will move eastward to the Great Lakes/Middle Mississippi Valley into the Central Rockies by Monday evening into Tuesday. Showers and thunderstorms will develop from the Northern Plains to the Upper Mississippi Valley on Sunday morning. By Sunday afternoon, showers and thunderstorms will develop along and ahead of the boundary from the Upper Great Lakes/Upper Mississippi Valley to the Central High Plains that will move eastward to the Great Lakes/Ohio Valley then westward to the Central Plains by Monday evening. In addition, onshore flow over the Pacific Northwest will end by Sunday morning. The associated rain over parts of the Northwest will end by later Sunday morning. Meanwhile, a dissipating boundary near Southeastern Florida will aid in producing showers and thunderstorms over parts of Southern Florida through Monday morning. Additionally, flow off the Western Gulf of Mexico with weak upper-level energy and daytime heating will aid in producing showers and thunderstorms over the Western/Central Gulf Coast through Monday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php