Short Range Forecast Discussion NWS Weather Prediction Center College Park MD 355 PM EDT Sat Sep 05 2015 Valid 00Z Sun Sep 06 2015 - 00Z Tue Sep 08 2015 ...There is a slight risk of severe thunderstorms over parts of the Northern High Plains... ...Heavy rain possible over parts of the Upper Great Lakes/Upper Mississippi Valley and the Middle Mississippi Valley... A slow moving front will advance eastward from the Northern Plains to the Upper Great Lakes by Monday, while the boundary trails southwestward into parts of the Great Basin. Showers and thunderstorms will develop along and near the front from the Northern Rockies to the Upper Mississippi Valley on Saturday evening. The showers and thunderstorms will taper off over the Northern Rockies to the Northern High Plains on Sunday. Showers and thunderstorms will develop along and ahead of the front on early Sunday morning over the Upper Mississippi Valley/Central Plains and move eastward to the Upper Great Lakes to Middle Mississippi Valley/Central Plains by Monday morning. Meanwhile, onshore flow and upper-level disturbances will aid in producing rain along parts of the Pacific Northwest through early Monday. In addition, monsoonal moisture and daytime heating will produce showers and thunderstorms over parts of the Southern/Central Rockies on Saturday afternoon and evening. The monsoonal showers and thunderstorms will wane on Sunday. Additionally, easterly flow off the Atlantic and upper-level energy over the Southeast/Central Gulf Coast will aid in producing showers and thunderstorms along the Southern Mid-Atlantic/Southeast Coast to parts of the Eastern/Central Gulf Coast through Monday morning. Furthermore, upper-level energy over parts of the Great Lakes will trigger scattered showers and thunderstorms over parts of the region on Saturday evening. Ziegenfelder Graphics available at www.wpc.ncep.noaa.gov/basicwx/basicwx_wbg.php